The Star Formation in Radio Survey: 3 - 33 GHz Imaging of Nearby Galaxy Nuclei and Extranuclear Star-forming Regions
S.T. Linden, E.J. Murphy, D. Dong, E. Momjian, R. C. Kennicutt Jr., D.S. Meier, E. Schinnerer, J.L. Turner
DDraft version April 23, 2020
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The Star Formation in Radio Survey: 3 – 33 GHz Imaging of Nearby Galaxy Nuclei and Extranuclear Star-formingRegions
S.T. Linden, E.J. Murphy, D. Dong, E. Momjian, R. C. Kennicutt Jr., D.S. Meier, E. Schinnerer, andJ.L. Turner Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904, USA National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA California Institute of Technology, MC 100-22, Pasadena, CA 91125, USA National Radio Astronomy Observatory, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801, USA Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801, USA Max Planck Institut f¨ur Astronomie, Knigstuhl 17, Heidelberg D-69117, Germany Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095, USA (Dated: April 23, 2020)
ABSTRACTWe present 3, 15, and 33 GHz imaging towards galaxy nuclei and extranuclear star-forming regionsusing the Karl G. Jansky Very Large Array as part of the Star Formation in Radio Survey. With3 −
33 GHz radio spectra, we measured the spectral indices and corresponding thermal (free-free)emission fractions for a sample of 335 discrete regions having significant detections in at least tworadio bands. After removing 14 likely background galaxies, we find that the median thermal fraction at33 GHz is 92 ± .
8% with a median absolute deviation of 11%, when a two-component power-law modelis adopted to fit the radio spectrum. Limiting the sample to 238 sources that are confidently identifiedas star-forming regions, and not affected by potential AGN contamination (i.e., having galactocentricradii r G ≥
250 pc), results in a median thermal fraction of 93 ± .
8% with a median absolute deviationof 10%. We further measure the thermal fraction at 33 GHz for 163 regions identified at 7 (cid:48)(cid:48) resolutionto be 94 ± .
8% with a median absolute deviation of 8%. Together, these results confirm that free-freeemission dominates the radio spectra of star-forming regions on scales up to ∼
500 pc in normal star-forming galaxies. We additionally find a factor of ∼ Keywords: galaxies: nuclei - H ii regions - radio continuum: general - stars: formation INTRODUCTIONThe radio spectra of star-forming galaxies, typi-cally characterized as a power law ( S ν ∝ ν α ), encodeinformation about the thermal and non-thermal en-ergetic processes which power them. Both thermal(Bremsstrahlung) and non-thermal (synchrotron) emis-sion are associated with massive ( ≥ M (cid:12) ) star forma-tion, underlying the basis for the well-known far-infrared(FIR: 42-122 µ m)-radio correlation (de Jong et al. 1985;Helou et al. 1985; Condon 1992; Bell 2003). FIR emis-sion arises from the absorption and re-radiation of UVand optical photons that heat dust grains surroundingmassive star-forming regions. The O and B stars in such regions, with lifetimes of ≤
10 Myr, produce ionizing(Lyman continuum) radiation whose strength is directlyproportional to the amount of free-free emission. Thesesame massive stars end their lives as core-collapse super-novae, whose remnants accelerate cosmic ray (CR) elec-trons/positrons that produce the diffuse non-thermalsynchrotron emission observed in star-forming galaxies(Condon 1992; Koyama et al. 1995; Murphy et al. 2006;Lacki & Thompson 2010; Lacki et al. 2010).However, the connection between the non-thermalsynchrotron emission and the current star-formationrate (SFR) of a galaxy is far less direct relative to ther-mal free-free emission. Variations in the generation andpropagation of CRs through the interstellar medium a r X i v : . [ a s t r o - ph . GA ] A p r Linden et al. (ISM) can affect the observed low-frequency emissionsurrounding star-forming regions. Despite the complex-ity in interpreting this non-thermal emission from galax-ies, several empirical (Bell 2003; Koyama et al. 1995;Murphy et al. 2006; Heesen et al. 2014; Tabatabaei et al.2017) and theoretical (Condon 1992; Murphy et al. 2011)calibrations for the star-formation rate (SFR) exist inthe literature. These studies demonstrate that at fre-quencies low enough (typically ∼ α NT ∼ − . ∼
30 GHz) the emission becomes dominated by ther-mal emission ( α T ∼ − . (cid:48)(cid:48) . In the initial investigation, Murphy et al.(2012) used the Westerbork Synthesis Radio Telescope(WSRT) in combination with the GBT to construct1.7-to-33 GHz radio spectra for 53 galaxy nuclei andextranuclear star-forming regions on ∼ kpc scales. Theyfound evidence that the measured thermal fraction at33 GHz varied significantly for star-forming regions ob-served at different physical resolution due to the rangein galaxy distance. Photometric apertures larger than ∼ − ≤ ∼ ii regions withinthese larger complexes, it is difficult to determine thephysical nature of these trends within nearby galaxies.This study served as the foundation for extendingthe SFRS into a multi-frequency Karl G. Jansky VeryLarge Array (VLA) campaign to image hundreds ofstar-forming regions in 50 galaxies taken from the Spitzer
Infrared Nearby Galaxies Survey (SINGS: Ken-nicutt et al. 2003) and the Key Insights on NearbyGalaxies: a Far-Infrared Survey (KINGFISH: Kenni-cutt et al. 2011). The results from our 33 GHz observa-tions, along with corresponding H α and Spitzer /MIPS24 µ m photometry were recently presented in Murphyet al. (2018a), hereafter M18a, and explored the H α -to-33 GHz and 24 µ m-to-33 GHz flux density ratios of star-forming regions as a function of galactocentric radiusand physical resolution. An outlier of these distribu-tions, NGC 4725 B, was later followed up with higher- frequency observations (Q-band: ∼
44 GHz) in order toconfirm this region as the second known source of extra-galactic anomalous microwave emission (AME: Murphyet al. 2018b). Building on this analysis, we have alsoobtained 3 and 15 GHz imaging for the SFRS, allowingus to map the full radio spectrum of each star-formingregion at a matched-resolution of ∼ (cid:48)(cid:48) . In this paper,we focus our presentation on the results associated withthe radio spectral indices and corresponding free-freeemission fractions for the entire sample.The paper is organized as follows: In § § §
4, and discussed in §
5. Our main conclusions aresummarized in §
6. In the Appendix we additionally pro-vide ancillary photometry from the Galaxy EvolutionExplorer (GALEX),
Spitzer , and ground-based H α ob-servations at a matched resolution of 7 (cid:48)(cid:48) that are notused in the present analysis. Throughout the paper wereport the median absolute deviations rather than stan-dard deviations, as this statistic is more resilient againstoutliers in a data set. SAMPLE AND DATA ANALYSISIn this section we describe the sample selection, andpresent the VLA observations along with the data re-duction and imaging procedures.2.1.
Sample Selection
The SFRS sample includes targeted observations from56 nearby galaxies ( d L <
30 Mpc) in the SINGS andKINGFISH legacy programs (Table 1). All nuclear andextranuclear star-forming regions were chosen to havemid-infrared spectral mappings carried out by the IRSinstrument on board
Spitzer , and
Herschel /PACS far-infrared spectral mappings, for a combination of theprincipal atomic ISM cooling lines ([OI] 63 µ m, [OIII]88 µ m, [NII] 122, 205 µ m, and [CII] 158 µ m). NGC 5194and NGC 2403 are exceptions; these galaxies were partof the SINGS sample, but are not formally includedin KINGFISH. They were observed with Herschel aspart of the Very Nearby Galaxy Survey (VNGS; PI:C. Wilson). Similarly, there are additional KINGFISHgalaxies that were not part of SINGS, but have exist-ing
Spitzer data: NGC 5457 (M101), IC 342, NGC 3077,and NGC 2146.The SINGS and KINGFISH galaxies are fully repre-sentative of the integrated properties and ISM condi-tions found in the local Universe, spanning the full rangein morphological types, as well as a factor of 100 in IR
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 1.
Galaxy Properties
Galaxy Type a Dist. b Nuc. Type c D i P.A. a (Mpc) (arcmin) ( ◦ ) ( ◦ )NGC 0337 SBd 19.3 SF 2 . × . · · · . × . . × . d NGC 0925 SABd 9.12 SF 10 . × . . × . . × . d NGC 1377 S0 24.6 · · · . × . . × .
21 153 d NGC 1482 SA0 22.6 SF 2 . × . . × . . × . · · · . × . . × . . × . . × . . × . . × . . × . . × . . × . . × . . × . . × . . × . . × . . × . . × . . × . d NGC 4254 SAc 14.4 SF/AGN 5 . × . d NGC 4321 SABbc 14.3 AGN 7 . × . . × . . × . . × . . × . . × . . × . d NGC 4631 SBd 7.62 SF(*) 15 . × . . × . . × . . × . . × . . × . · · · . × . . × .
26 29 d NGC 5474 SAcd 6.8 SF(*) 4 . × . d NGC 5713 SABbcp 21.4 SF 2 . × . . × . . × . d NGC 7331 SAb 14.5 AGN 10 . × . . × . a Morphological types, diameters, and position angles were taken from theThird Reference Catalog of Bright Galaxies (RC3: de Vaucouleurs et al. 1991). b Redshift-independent distance taken from the list compiled by Kennicutt et al.(2011), except for the two non-KINGFISH galaxies NGC 5194 (Ciardullo et al.2002) and NGC 2403 (Freedman et al. 2001). c Nuclear type based on optical spectroscopy: SF = Star-Forming; AGN =Non-thermal emission as given in Table 5 of Moustakas et al. (2010) or (*)Table 4 of Lonsdale Persson & Helou (1987). d Position angle taken from Jarrett et al. (2003).
Linden et al. luminosity ( L IR : 8-1000 µ m), global IR/optical flux ra-tio, and the star formation rate. Similarly, the spectro-scopically targeted star-forming regions included in theSFRS cover the full range of physical conditions foundin nearby galaxies, including the extinction-correctedproduction rate of ionizing photons Q ( H ), metallicity,visual extinction, radiation field intensity, and ionizingstellar temperature.The full sample over the entire sky consists of 118star-forming complexes (56 nuclei and 62 extranuclearregions), 112 of which (50 nuclei and 62 extranuclearregions; see Tables 2 and 3, respectively) are observ-able with the VLA (i.e., having δ > − ◦ ). The co-ordinates given in both tables list the pointing cen-ter for the VLA observations (see Section 2.2), whichcorrespond to the centers of the Spitzer mid-infraredand
Herschel far-infrared spectral line maps. Morpholo-gies, adopted distances, optically-defined nuclear types,diameters ( D ), inclinations ( i ), and position angles(P.A.) for each source are given in Table 1 and describedin detail in M18a.2.2. VLA Observations and Data Reduction
The observational set-up and reduction procedure forthe Ka-band (29 −
37 GHz) data (11B-032,13A-129) isdescribed in detail in M18a. Observations in the S-band (2 − −
18 GHz)were taken November 2014 in the C-configuration (13B-215) using the 3-bit samplers. Both sets of observationsutilized the full available bandwidth of the respective re-ceivers. Given the large range in brightness among ourtargeted regions, we varied the time spent on-source byestimating the expected 3 −
15 GHz flux density usingthe
Spitzer /MIPS 24 µ m maps. The median integra-tion time for regions in our sample was ∼
10 minutesat both frequencies. The choice of array configurationswere made to match the angular resolution (i.e., FWHMof the synthesized beam ∼ (cid:48)(cid:48) ) of the observations ateach band. This allows us to probe the same spatialscales across the full 3 −
33 GHz frequency range, andensures that any differences in the measured spectral in-dex of individual star-forming regions is due to physicalvariation in the region being measured, and not due toresolving out more emission at higher frequencies.The standard VLA flux density calibrators 3C48,3C286, and 3C147 were used, and the data reduc-tion procedures presented in M18a are repeated for ourpresent analysis, and briefly described here. To reducethe VLA data, we used the Common Astronomy Soft-ware Applications (CASA; McMullin et al. 2007) ver- sions 4.6.0 and 4.7.0, and followed standard calibrationand flagging procedures, including the utilization of theVLA calibration pipeline. We further inspected the vis-ibilities and calibration tables for evidence of bad anten-nas, frequency ranges, and time ranges, flagging corre-spondingly. We also flagged any instances of radio fre-quency interference (RFI). Importantly, the fractionalbandwidth of our observations lost to RFI flagging isnegligible relative to the full bandwidth of the receivers.After flagging, we re-ran the pipeline, and repeated thisprocess until all poorly-calibrated data were removed.For all delay and bandpass tables applied on-the-fly,we used the default nearest-neighbor interpolation. Forcomplex gain and flux density scale tables, we used alinear interpolation.2.3.
Interferometric Imaging
Calibrated VLA measurement sets for each sourcewere imaged using the task tclean in CASA version4.6.0. For some cases, the Ka-band images contain datafrom observations taken during both the 11B and 13Asemesters, but are heavily weighted by the 13A semesterobservations, as those include significantly more data.The mode of tclean was set to multi-frequency syn-thesis ( mfs ; Conway et al. 1990; Sault & Wieringa1994). We chose a pixel scale of 0 . (cid:48)(cid:48) robust = 0 . nterms = 2. This allows the cleaning procedure toalso model the spectral index variations on the sky. Al-though this procedure utilizes the large fractional band-widths of each observation to generate in-band spectralindex maps, we do not use them in our analysis giventhat the signal-to-noise ratio ( S/N ) of our sources istypically too low for them to be reliable. To help de-convolve extended low-intensity emission, we took ad-vantage of the multiscale clean option (Cornwell 2008;Rau & Cornwell 2011) in CASA, searching for structureswith scales ∼ impbcor before analyzing the images. Theprimary-beam-corrected continuum images at 3 − −
33 GHz frequency range, we use
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 2.
Nuclear Source Positions and Imaging Characteristics σ σ T b Synthesized σ σ T b (J2000) (J2000) Beam ( µ Jy bm − ) (mK) Beam ( µ Jy bm − ) (mK)NGC 0337 00 59 50 . −
07 34 44 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
74 18.7 597.32 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
13 9.1 21.71NGC 0628 01 36 41 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
78 14.0 543.15 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
19 9.6 28.14NGC 0855 02 14 03 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
62 13.2 613.61 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
25 8.6 24.93NGC 0925 02 27 17 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
59 13.0 611.30 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
23 9.1 27.04NGC 1097 02 46 19 . −
30 16 28 5 . (cid:48)(cid:48) × . (cid:48)(cid:48)
80 44.9 586.45 3 . (cid:48)(cid:48) × . (cid:48)(cid:48)
99 16.9 24.11NGC 1266 03 16 00 . −
02 25 38 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
78 14.0 485.33 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
17 11.3 28.86NGC 1377 03 36 38 . −
20 54 06 3 . (cid:48)(cid:48) × . (cid:48)(cid:48)
71 17.4 385.40 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
09 11.6 21.93IC 0342 03 46 48 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
76 41.6 1430.61 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
13 11.4 31.44NGC 1482 03 54 39 . −
20 30 07 3 . (cid:48)(cid:48) × . (cid:48)(cid:48)
67 16.8 419.18 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
33 14.1 23.56NGC 2146 06 18 37 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
55 35.5 1214.57 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
94 14.9 44.68NGC 2403 07 36 50 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
53 13.8 551.32 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
15 9.8 24.41Holmberg II 08 19 13 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
67 14.9 465.55 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
15 9.4 22.41NGC 2798 09 17 22 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
78 14.6 520.66 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
38 11.3 27.83NGC 2841 09 22 02 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
62 13.3 526.88 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
23 18.1 50.13NGC 2976 09 47 15 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
66 14.4 413.49 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
13 9.7 23.08NGC 3049 09 54 49 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
84 14.9 510.77 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
13 12.2 27.98NGC 3077 10 03 19 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
67 14.4 402.59 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
12 10.2 24.82NGC 3190 10 18 05 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
81 13.5 475.29 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
26 8.5 22.63NGC 3184 10 18 16 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
76 14.0 444.09 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
18 8.5 30.49NGC 3198 10 19 54 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
66 14.4 521.10 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
17 8.5 29.06IC 2574 10 28 48 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
64 14.2 393.53 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
14 8.8 20.73NGC 3265 10 31 06 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
78 14.9 505.30 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
25 7.8 23.42NGC 3351 10 43 57 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
75 18.4 708.89 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
67 15.3 25.34NGC 3521 11 05 48 . −
00 02 06 3 . (cid:48)(cid:48) × . (cid:48)(cid:48)
95 19.9 448.93 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
19 16.4 39.79NGC 3621 11 18 16 . −
32 48 42 4 . (cid:48)(cid:48) × . (cid:48)(cid:48)
53 15.7 291.11 4 . (cid:48)(cid:48) × . (cid:48)(cid:48)
08 8.5 10.16NGC 3627 11 20 15 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
77 15.7 616.48 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
97 14.0 16.23NGC 3773 11 38 13 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
76 13.1 518.26 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
14 9.8 30.21NGC 3938 11 52 49 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
73 15.1 376.61 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
10 7.9 31.23NGC 4254 12 18 49 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
81 15.3 577.12 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
11 9.0 28.58NGC 4321 12 22 54 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
72 15.0 622.65 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
17 9.8 29.55NGC 4536 12 34 27 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
86 15.5 524.37 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
45 10.2 15.58NGC 4559 12 35 57 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
63 13.6 646.04 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
27 9.0 29.13NGC 4569 12 36 49 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
80 15.4 572.68 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
18 10.7 29.15NGC 4579 12 37 43 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
85 23.4 807.73 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
21 50.9 132.87NGC 4594 12 39 59 . −
11 37 23 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
74 19.7 554.75 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
09 13.4 32.88NGC 4625 12 41 52 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
56 13.5 677.51 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
17 9.7 29.19NGC 4631 12 42 05 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
76 14.3 597.52 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
83 12.9 16.71NGC 4725 12 50 26 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
76 13.5 561.64 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
26 9.0 29.20NGC 4736 12 50 53 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
55 13.9 706.09 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
06 13.4 15.67NGC 4826 12 56 43 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
75 14.3 559.38 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
33 10.1 28.20NGC 5055 13 15 49 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
60 12.8 619.07 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
17 9.7 29.58NGC 5194 13 29 52 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
57 17.0 820.75 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
15 9.3 28.43NGC 5398 14 01 20 . −
33 04 09 6 . (cid:48)(cid:48) × . (cid:48)(cid:48)
76 20.6 239.46 3 . (cid:48)(cid:48) × . (cid:48)(cid:48)
03 8.4 11.09NGC 5457 14 03 12 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
67 13.9 619.05 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
10 8.6 27.29NGC 5474 14 05 01 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
71 14.3 616.05 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
07 11.9 40.40NGC 5713 14 40 11 . −
00 17 27 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
77 17.6 526.76 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
80 15.4 19.67NGC 5866 15 06 29 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
63 13.8 595.03 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
20 15.4 42.92NGC 6946 20 34 52 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
64 16.1 655.75 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
12 9.5 21.44NGC 7331 22 37 04 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
67 15.1 672.97 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
21 10.0 29.80NGC 7793 23 57 49 . −
32 35 24 4 . (cid:48)(cid:48) × . (cid:48)(cid:48)
62 14.0 245.06 4 . (cid:48)(cid:48) × . (cid:48)(cid:48)
08 9.4 10.50
Note —See Murphy et al. (2018a) for the 33 GHz imaging characteristics.
Linden et al.
Table 3.
Extranuclear Source Positions and Imaging Characteristics σ σ T b Synthesized σ σ T b (J2000) (J2000) Beam ( µ Jy bm − ) (mK) Beam ( µ Jy bm − ) (mK)NGC 0628 Enuc. 1 01 36 45 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
78 14.0 542.77 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
21 9.8 28.16NGC 0628 Enuc. 2 01 36 37 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
78 14.0 544.62 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
22 9.6 27.27NGC 0628 Enuc. 3 01 36 38 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
78 14.0 542.12 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
23 9.6 26.82NGC 0628 Enuc. 4 01 36 35 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
78 13.8 537.98 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
20 8.0 23.07NGC 1097 Enuc. 1 02 46 23 . −
30 17 51 5 . (cid:48)(cid:48) × . (cid:48)(cid:48)
80 41.2 537.94 3 . (cid:48)(cid:48) × . (cid:48)(cid:48)
95 11.8 17.84NGC 1097 Enuc. 2 02 46 14 . −
30 15 05 5 . (cid:48)(cid:48) × . (cid:48)(cid:48)
80 38.3 500.07 3 . (cid:48)(cid:48) × . (cid:48)(cid:48)
98 11.4 16.42NGC 2403 Enuc. 1 07 36 45 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
53 13.7 548.00 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
16 9.4 23.61NGC 2403 Enuc. 2 07 36 52 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
53 13.7 547.71 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
15 9.5 23.96NGC 2403 Enuc. 3 07 37 06 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
53 13.7 548.41 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
16 9.7 24.51NGC 2403 Enuc. 4 07 37 17 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
53 13.7 546.14 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
15 9.5 24.86NGC 2403 Enuc. 5 07 36 19 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
53 13.5 541.72 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
15 9.5 24.84NGC 2403 Enuc. 6 07 36 28 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
53 13.5 541.23 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
13 9.7 26.15NGC 2976 Enuc. 1 09 47 07 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
66 14.5 415.03 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
13 9.8 23.62NGC 2976 Enuc. 2 09 47 24 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
66 14.4 412.17 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
13 10.0 24.19NGC 3521 Enuc. 1 11 05 46 . −
00 04 10 3 . (cid:48)(cid:48) × . (cid:48)(cid:48)
95 19.4 436.89 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
22 14.0 32.41NGC 3521 Enuc. 2 11 05 49 . −
00 03 40 3 . (cid:48)(cid:48) × . (cid:48)(cid:48)
95 19.8 445.88 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
11 11.7 27.66NGC 3521 Enuc. 3 11 05 47 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
95 18.9 425.62 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
13 11.6 25.02NGC 3627 Enuc. 1 11 20 16 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
77 15.4 604.26 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
22 9.0 26.70NGC 3627 Enuc. 2 11 20 16 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
77 15.7 614.25 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
41 15.7 31.48NGC 3627 Enuc. 3 11 20 16 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
77 15.7 616.15 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
17 13.4 40.92NGC 3938 Enuc. 1 11 52 46 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
73 15.0 374.91 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
12 8.3 31.38NGC 3938 Enuc. 2 11 53 00 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
73 14.8 368.03 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
12 8.3 31.40NGC 4254 Enuc. 1 12 18 49 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
81 15.1 567.30 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
14 8.5 26.05NGC 4254 Enuc. 2 12 18 44 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
81 15.3 575.22 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
16 9.6 29.55NGC 4321 Enuc. 1 12 22 58 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
72 14.9 620.02 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
18 9.8 29.30NGC 4321 Enuc. 2 12 22 49 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
72 14.9 618.78 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
18 9.9 29.98NGC 4631 Enuc. 1 12 41 40 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
75 14.0 577.02 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
27 9.1 23.44NGC 4631 Enuc. 2 12 42 21 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
76 13.9 578.32 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
28 9.0 23.48NGC 4736 Enuc. 1 12 50 56 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
55 13.9 705.86 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
17 12.9 38.89NGC 5055 Enuc. 1 13 15 58 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
60 13.1 630.58 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
17 9.9 30.50NGC 5194 Enuc. 1 13 29 53 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
57 16.8 810.49 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
14 9.1 28.20NGC 5194 Enuc. 2 13 29 44 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
52 17.0 863.15 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
14 8.9 27.62NGC 5194 Enuc. 3 13 29 44 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
52 16.9 858.25 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
14 9.1 28.37NGC 5194 Enuc. 4 13 29 56 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
57 16.0 768.85 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
14 9.5 29.61NGC 5194 Enuc. 5 13 29 59 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
57 16.1 773.77 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
14 9.7 30.21NGC 5194 Enuc. 6 13 29 39 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
52 15.8 805.61 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
12 8.7 27.81NGC 5194 Enuc. 7 13 30 02 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
52 17.8 904.22 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
11 9.3 29.80NGC 5194 Enuc. 8 13 30 01 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
57 16.7 803.48 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
18 9.7 28.04NGC 5194 Enuc. 9 13 29 59 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
57 17.0 819.52 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
16 10.7 31.20NGC 5194 Enuc. 10 13 29 56 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
52 18.1 921.23 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
16 10.8 31.55NGC 5194 Enuc. 11 13 29 49 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
57 16.3 783.23 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
21 12.8 36.27NGC 5457 Enuc. 1 14 03 10 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
67 13.8 615.51 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
10 8.4 26.65NGC 5457 Enuc. 2 14 02 55 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
63 14.1 643.39 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
09 8.5 27.14NGC 5457 Enuc. 3 14 03 41 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
67 14.1 627.94 4 . (cid:48)(cid:48) × . (cid:48)(cid:48)
20 25.0 13.13NGC 5457 Enuc. 4 14 03 53 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
73 13.8 590.56 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
08 9.5 30.71NGC 5457 Enuc. 5 14 03 01 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
63 13.8 629.72 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
07 10.8 36.48NGC 5457 Enuc. 6 14 02 28 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
67 13.7 596.38 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
06 11.9 39.68NGC 5457 Enuc. 7 14 04 29 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
73 13.7 589.02 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
04 13.0 44.82NGC 5713 Enuc. 1 14 40 12 . −
00 17 47 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
77 17.6 525.60 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
80 15.9 20.36NGC 5713 Enuc. 2 14 40 10 . −
00 17 47 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
77 17.6 527.29 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
80 15.9 20.36NGC 6946 Enuc. 1 20 35 16 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
64 15.2 616.55 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
10 8.3 19.75NGC 6946 Enuc. 2 20 35 25 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
64 15.0 609.01 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
09 9.8 24.32NGC 6946 Enuc. 3 20 34 52 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
64 15.0 608.66 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
09 8.7 20.65NGC 6946 Enuc. 4 20 34 19 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
64 14.8 603.01 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
90 10.1 11.78NGC 6946 Enuc. 5 20 34 39 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
63 15.1 604.38 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
11 8.8 22.34NGC 6946 Enuc. 6 20 35 06 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
64 15.7 636.59 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
11 8.6 21.28NGC 6946 Enuc. 7 20 35 11 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
64 15.7 636.59 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
13 8.8 19.64NGC 6946 Enuc. 8 20 34 32 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
63 15.8 639.98 1 . (cid:48)(cid:48) × . (cid:48)(cid:48)
11 8.7 21.20NGC 6946 Enuc. 9 20 35 12 . . (cid:48)(cid:48) × . (cid:48)(cid:48)
64 15.7 636.59 2 . (cid:48)(cid:48) × . (cid:48)(cid:48)
13 8.8 19.64NGC 7793 Enuc. 1 23 57 48 . −
32 36 59 4 . (cid:48)(cid:48) × . (cid:48)(cid:48)
62 13.9 243.82 4 . (cid:48)(cid:48) × . (cid:48)(cid:48)
09 9.6 10.26NGC 7793 Enuc. 2 23 57 56 . −
32 35 40 4 . (cid:48)(cid:48) × . (cid:48)(cid:48)
62 14.0 244.33 4 . (cid:48)(cid:48) × . (cid:48)(cid:48)
11 9.8 10.09NGC 7793 Enuc. 3 23 57 48 . −
32 34 53 4 . (cid:48)(cid:48) × . (cid:48)(cid:48)
62 14.0 245.29 4 . (cid:48)(cid:48) × . (cid:48)(cid:48)
08 8.8 9.84
Note —See Murphy et al. (2018a) for the 33 GHz imaging characteristics.
FRS: 3 - 33 GHz Imaging of Star-Forming Regions imsmooth to match all VLA images foreach pointing to a common circularized, Gaussian, beamcorresponding to the lowest angular resolution amongall three frequency bands scaled by a factor of √ × . (cid:48)(cid:48) imsmooth to havelength zero in any axis in units of pixels. We additionallycrop all images to a common field-of-view (FOV) equalto the FOV of our 33 GHz observations (i.e., a primarybeam FWHM of 44 (cid:48)(cid:48) ). ANCILLARY DATA AND PHOTOMETRYIn this section we provide a description of ancillarydata used, as well as our procedure for extracting consis-tent aperture photometry across the full suite of multi-wavelength data available for galaxies in the SFRS.3.1.
Ancillary Data
GALEX far-UV (FUV; 1528˚A) and near-UV (NUV;2271˚A) data were taken from the GALEX Large GalaxyAtlas (Seibert 2007). The calibration uncertainty forthese data is ∼
15% in both bands. One galaxy,NGC 1377, does not have existing near- or far-UV imag-ing.The H α data used in this analysis is taken from thecompilation presented in Leroy et al. (2012), where de-tails about the data quality and preparation (e.g., cor-rection for [NII] emission) can be found, as well as theSINGS archive. All H α images were then further cor-rected for foreground stars. The typical resolution ofthe seeing-limited H α images is ∼ − (cid:48)(cid:48) , and the cal-ibration uncertainty among these maps is taken to be ∼ α imaging from SINGS.Archival Spitzer µ m and 24 µ m data were largelytaken from the SINGS and Local Volume Legacy (LVL)legacy programs, and have a calibration uncertainty of ∼ µ m imaging comesfrom Engelbracht et al. (2008).Finally, in order to account for the significant differ-ences between the point-spread functions (PSF) of thevarious telescopes used in this analysis, we implementthe convolution kernels presented in Aniano et al. (2011)to convolve the instrumental PSF for each image, andproduce a corrected Gaussian beam of 7 (cid:48)(cid:48) at each wave-length.3.2. Region Identification and Aperture Photometry
To identify and characterize potential star-forming re-gions in the SFRS, we start by searching within an area that is equal to twice the FWHM of the VLA primarybeam at 33 GHz ( ∼ µ m maps of each galaxy todetermine if the source has a corresponding detectionin the mid-IR, and is thus likely associated with a star-forming region. Sources characterized as potential back-ground galaxies have no obvious 8 µ m counterpart, andvery rarely a 33 GHz counterpart. In total, we visu-ally identified 389 regions for which we perform aper-ture photometry to determine those that are statisticallysignificant detections. Of the 389 sources visually iden-tified, 377 had a statistically significant detection (i.e., S/N >
3) in at least one band, which is given in Table4. For completeness, the remaining 12 sources are stilllabeled in the panels of Figure 1 to demonstrate the fullidentification process we utilized.Using the CASA task imstat , we measured and reportthe 3 −
33 GHz flux densities for each region. The size ofthe apertures were hand-selected to fully encompass thevisible extent of the 3 −
33 GHz radio flux density of eachregion, with an additional constraint of having a diame-ter equal to or larger than the FWHM of the synthesizedbeam for that pointing. We do not apply aperture cor-rections to our photometry given that we both convolveall images for a given pointing to common beam and usethe same sized aperture at all wavelengths. Photomet-ric uncertainties were conservatively estimated by tak-ing the empirically measured noise from empty regionsin each non primary beam corrected image, applying theempirical primary beam correction based on Equation 4in EVLA Memo 195, and scaling by the ratio of the syn-thesized beam area to the adopted aperture area. Thisnoise is then added in quadrature with the VLA cali-bration uncertainty ( ∼ ± . α , and Spitzer /MIPS 24 µ m datasetsafter matching their resolution (7 (cid:48)(cid:48) FWHM), croppingeach image to a common field of view, and re-griddingto a common pixel scale (0 . (cid:48)(cid:48) (cid:48)(cid:48) were usedin all cases. Unlike our native-resolution photometry,we report sources with upper-limits in all radio bandsif a statistically significant detection exists in our an-cillary GALEX and Spitzer imaging. The median sizeof the apertures used at 7 (cid:48)(cid:48) resolution is 259 ± . Linden et al.
Figure 1. min )/(p max -p min )], where pis the pixel value and a = 1 /
3, 0.5, 1.0, and 2.0. A cube-root stretch of a = 1 / S/N > a = 0 . < S/N < < S/N <
50, and a square stretch was used when the brightestpixel had a
S/N <
10. A scalebar of 10 (cid:48)(cid:48) is also given in the bottom right corner of each panel. To distinguish between individualsources identified in the full-resolution and 7 (cid:48)(cid:48) smoothed maps, we use uppercase and lowercase letters as part of their namesfor reporting photometry in Tables 4 and 5, respectfully. An extended version of this Figure is available in the Appendix.
FRS: 3 - 33 GHz Imaging of Star-Forming Regions α photometry of each region was corrected for MilkyWay extinction using Schlegel et al. (1998) assuming A V /E ( B − V ) = 3 . α , and Spitzer /MIPS 24 µ m photom-etry results, which are presented in Table 6, are not useddirectly in the present analysis, but will be utilized forfurther studies.Finally, in order to account for and remove any dif-fuse emission component that is most likely unassoci-ated with the most recent star formation activity in thedisks of these galaxies, we measure a local backgroundvalue within the vicinity of each star-forming region. Thelocal background was measured by placing an annulusa distance of 1.5 times the synthesized beam FWHMaway from the center of the source position in both thefull-resolution and smoothed maps. The median sur-face brightness within this annulus was then multipliedby the effective area of the beam to get an estimateof the local diffuse background emission. These valuesare given in Table 7. Further, we measure the frac- tional contribution of the background emission for eachregion, and find that the median value is 4 . ± . . ± . . ± . . . .
5% for our 3, 15, and 33 GHzobservations respectively. Importantly, these values aresmaller than the 15 −
40% found for the regions studiedat 25 (cid:48)(cid:48) ( ∼ (cid:48)(cid:48) smoothedmaps by instead using a lowercase letter. For example,“NGC 2403 Enuc. 2 b” is one of two regions in the imageof extranuclear region 2 in NGC 2403, and is composedof the sum contribution of “NGC 2403 Enuc. 2 B” and“NGC 2403 Enuc. 2 C” in the full-resolution maps. Table 4 . Region Photometry and Derived Parameters
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)Star-Forming RegionsNGC 0337 D 00 59 49.94 -07 34 47.60 1 . ± .
07 0 . ± .
04 0 . ± .
05 655. 0.921 − . ± .
042 0 . ± . . ± .
06 0 . ± .
03 0 . ± .
05 561. 0.881 − . ± .
042 0 . ± . . ± .
07 2 . ± .
04 1 . ± .
07 749. 2.041 − . ± .
012 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 281. 3.735 − . ± .
060 1 . ± . . ± .
05 0 . ± .
03 0 . ± .
05 468. 3.123 − . ± .
102 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 281. 4.048 0 . ± .
059 1 . ± . . ± .
04 0 . ± .
02 0 . ± .
04 374. 3.753 − . ± .
087 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 140. 7.614 − . ± .
065 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
04 140. 4.468 − . ± .
044 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
04 105. 5.798 − . ± .
057 0 . ± . †
01 36 38.84 +15 44 22.90 0 . ± .
06 0 . ± .
04 0 . ± .
10 279. 5.724 − . ± .
080 1 . ± . . ± .
02 0 . ± .
02 0 . ± .
04 105. 5.657 − . ± .
058 0 . ± . < . ± . < · · · · · · NGC 0628 Enuc. 1 A 01 36 45.25 +15 47 48.06 0 . ± .
04 0 . ± .
04 0 . ± .
07 209. 2.466 − . ± .
111 1 . ± . . ± .
06 1 . ± .
04 0 . ± .
07 377. 0.072 − . ± .
027 0 . ± . †
02 14 03.80 +27 52 37.85 2 . ± .
10 1 . ± .
06 0 . ± .
11 613. 0.305 − . ± .
034 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 189. 0.910 − . ± .
062 0 . ± . . ± .
02 0 . ± . < − . ± .
082 1 . ± . . ± . < < · · · · · · NGC 0925 B 02 27 20.62 +33 34 29.80 0 . ± .
02 0 . ± . < − . ± .
095 0 . ± . . ± . < . ± .
08 138. 7.378 − . ± .
147 0 . ± . . ± .
10 2 . ± .
04 2 . ± .
07 275. 0.813 − . ± .
009 0 . ± . . ± .
10 3 . ± .
04 3 . ± .
07 275. 0.052 − . ± .
010 0 . ± . Table 4 continued Linden et al.
Table 4 (continued)
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)NGC 1097 A †
02 46 18.96 -30 16 29.20 104 . ± .
35 28 . ± .
15 21 . ± .
25 964. 0.052 − . ± .
003 0 . ± . . ± .
10 2 . ± .
04 1 . ± .
07 275. 0.831 − . ± .
010 0 . ± . . ± .
10 3 . ± .
04 2 . ± .
07 275. 0.514 − . ± .
008 0 . ± . < < . ± .
05 688. 7.301 · · · · · ·
NGC 1266 C 03 16 00.76 -02 25 36.50 30 . ± .
03 8 . ± .
02 5 . ± .
07 445. 0.390 − . ± .
001 0 . ± . †
03 16 00.76 -02 25 39.20 35 . ± .
08 6 . ± .
04 3 . ± .
16 1038. 0.267 − . ± .
004 0 . ± . . ± .
03 4 . ± .
02 2 . ± .
07 445. 0.964 − . ± .
003 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 358. 0.344 − . ± .
141 0 . ± . . ± .
12 18 . ± .
03 13 . ± .
08 64. 0.065 − . ± .
002 0 . ± . †
03 46 48.45 +68 05 46.30 90 . ± .
30 36 . ± .
08 27 . ± .
20 159. 0.007 − . ± .
002 0 . ± . . ± .
12 10 . ± .
03 8 . ± .
08 64. 0.074 − . ± .
003 0 . ± . . ± .
12 0 . ± . < − . ± .
184 0 . ± . . ± .
03 12 . ± .
02 9 . ± .
15 438. 0.272 − . ± .
001 0 . ± . †
03 54 38.97 -20 30 08.20 117 . ± .
09 24 . ± .
06 11 . ± .
40 1205. 0.104 − . ± .
002 0 . ± . . ± .
03 12 . ± .
02 8 . ± .
14 438. 0.516 − . ± .
001 0 . ± . . ± .
14 0 . ± .
06 2 . ± .
12 417. 3.862 − . ± .
024 0 . ± . . ± .
08 1 . ± .
03 5 . ± .
06 250. 2.205 − . ± .
005 0 . ± . . ± .
08 1 . ± .
03 9 . ± .
06 250. 1.322 − . ± .
002 0 . ± . . ± .
22 21 . ± .
08 61 . ± .
15 667. 0.410 − . ± .
001 0 . ± . . ± .
11 0 . ± .
04 3 . ± .
09 334. 3.245 − . ± .
011 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 62. 3.520 − . ± .
016 0 . ± . †
07 36 19.84 +65 37 06.70 2 . ± .
06 2 . ± .
04 1 . ± .
05 140. 3.458 − . ± .
016 1 . ± . . ± .
03 0 . ± . < . ± .
098 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 62. 3.150 − . ± .
104 0 . ± . . ± .
05 0 . ± .
04 0 . ± .
03 125. 5.369 − . ± .
029 1 . ± . . ± . < . ± .
02 62. 4.933 − . ± .
165 0 . ± . . ± .
03 0 . ± . < . ± .
098 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 62. 1.085 − . ± .
040 0 . ± . . ± .
03 0 . ± . < . ± .
186 1 . ± . . ± .
06 1 . ± .
04 1 . ± .
04 125. 1.203 − . ± .
021 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 62. 0.753 − . ± .
093 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 62. 0.697 − . ± .
103 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
04 94. 1.115 − . ± .
067 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 47. 1.258 − . ± .
018 1 . ± . †
07 36 52.46 +65 36 45.70 2 . ± .
06 1 . ± .
04 1 . ± .
04 125. 1.229 − . ± .
016 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 47. 1.247 − . ± .
021 0 . ± . . ± . < < · · · · · · NGC 2403 E 07 36 56.727 +65 35 12.17 0 . ± . < < · · · · · · NGC 2403 Enuc. 3 B 07 37 06.66 +65 36 38.40 3 . ± .
04 3 . ± .
03 2 . ± .
04 78. 2.763 − . ± .
006 0 . ± . < . ± .
02 0 . ± .
02 62. 3.305 − . ± .
358 0 . ± . < . ± .
02 0 . ± .
02 62. 3.556 − . ± .
359 0 . ± . . ± .
06 0 . ± .
04 0 . ± .
03 125. 3.446 − . ± .
028 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
02 44. 0.721 0 . ± .
078 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 59. 0.739 − . ± .
048 1 . ± . . ± .
02 0 . ± .
02 0 . ± .
03 375. 2.580 − . ± .
022 0 . ± . . ± .
06 2 . ± .
06 0 . ± .
07 1001. 0.217 − . ± .
013 0 . ± . . ± . < < · · · · · · NGC 2976 Enuc. 1 A 09 47 05.09 +67 55 51.70 1 . ± .
03 0 . ± .
02 0 . ± .
05 86. 1.432 − . ± .
020 0 . ± . . ± .
02 1 . ± .
02 1 . ± .
03 69. 1.208 − . ± .
008 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
02 52. 1.111 − . ± .
027 0 . ± . †
09 47 07.85 +67 55 53.98 3 . ± .
06 2 . ± .
05 2 . ± .
08 172. 1.178 − . ± .
014 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
03 69. 0.432 − . ± .
090 1 . ± . < . ± . < · · · · · · Table 4 continued
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 4 (continued)
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)NGC 2976 Enuc. 2 A 09 47 23.94 +67 53 53.40 1 . ± .
04 1 . ± .
03 1 . ± .
06 120. 1.421 − . ± .
018 1 . ± . . ± .
04 0 . ± .
03 0 . ± .
05 103. 1.278 − . ± .
047 0 . ± . . ± . < < · · · · · · NGC 3049 A 09 54 49.56 +09 16 16.05 1 . ± .
04 0 . ± .
04 0 . ± .
04 559. 0.110 − . ± .
032 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 372. 1.033 − . ± .
070 0 . ± . . ± . < < · · · · · · NGC 3077 A 10 03 19.15 +68 43 59.90 11 . ± .
06 7 . ± .
05 6 . ± .
12 186. 0.045 − . ± .
005 0 . ± . . ± .
03 0 . ± .
02 1 . ± .
04 374. 9.635 0 . ± .
024 1 . ± . . ± .
04 0 . ± . < − . ± .
153 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
03 340. 0.057 − . ± .
044 0 . ± . . ± .
04 0 . ± . < − . ± .
193 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
05 410. 0.180 − . ± .
074 0 . ± . . ± .
04 0 . ± . < . ± .
201 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
08 92. 5.606 − . ± .
040 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
08 129. 6.262 − . ± .
034 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 92. 5.247 − . ± .
031 0 . ± . . ± .
02 0 . ± . < . ± .
195 1 . ± . . ± .
05 0 . ± .
03 0 . ± .
04 665. 0.090 − . ± .
024 0 . ± . . ± .
04 1 . ± .
04 1 . ± .
19 181. 2.844 − . ± .
024 0 . ± . . ± .
06 2 . ± .
04 1 . ± .
05 271. 0.267 − . ± .
009 0 . ± . . ± .
06 3 . ± .
04 2 . ± .
05 271. 0.271 − . ± .
007 0 . ± . . ± .
04 0 . ± . < . ± .
194 1 . ± . < . ± . < · · · · · · NGC 3521 Enuc. 2 A 11 05 49.28 -00 03 26.70 0 . ± .
04 0 . ± .
04 0 . ± .
05 271. 4.474 − . ± .
058 0 . ± . . ± . < < · · · · · · NGC 3521 Enuc. 2 B 11 05 51.04 -00 03 49.20 0 . ± .
04 0 . ± . < . ± .
104 1 . ± . . ± .
04 0 . ± . < − . ± .
105 0 . ± . . ± .
04 0 . ± . < − . ± .
071 0 . ± . . ± . < < · · · · · · NGC 3621 G †
11 18 18.117 -32 49 39.41 2 . ± .
07 1 . ± . < − . ± .
040 0 . ± . . ± .
05 0 . ± . < − . ± .
074 0 . ± . . ± . < < · · · · · · NGC 3621 E 11 18 21.542 -32 49 08.39 0 . ± .
04 0 . ± . < − . ± .
162 0 . ± . . ± . < < · · · · · · NGC 3627 Enuc. 1 F 11 20 12.848 +12 57 56.98 0 . ± . < < · · · · · · NGC 3627 Enuc. 1 E 11 20 12.989 +12 57 36.49 0 . ± . < . ± .
10 182. 6.672 0 . ± .
116 1 . ± . . ± .
07 2 . ± .
10 1 . ± .
37 364. 3.072 − . ± .
028 0 . ± . . ± .
05 1 . ± .
06 0 . ± .
05 273. 0.023 − . ± .
026 0 . ± . . ± .
03 2 . ± .
04 1 . ± .
02 136. 2.534 − . ± .
005 0 . ± . . ± .
05 1 . ± .
06 1 . ± .
05 273. 4.706 − . ± .
017 0 . ± . †
11 20 16.53 +12 58 44.30 7 . ± .
09 4 . ± .
12 3 . ± .
08 455. 2.781 − . ± .
010 0 . ± . . ± .
03 2 . ± .
04 1 . ± .
02 136. 2.994 − . ± .
006 0 . ± . . ± .
03 0 . ± .
05 0 . ± .
05 182. 4.390 − . ± .
072 0 . ± . . ± .
03 0 . ± . < − . ± .
081 0 . ± . . ± .
04 1 . ± .
04 1 . ± .
05 481. 0.023 − . ± .
016 0 . ± . . ± . < < · · · · · · NGC 3938 Enuc. 2 B 11 52 59.97 +44 08 00.00 0 . ± .
02 0 . ± .
02 0 . ± .
03 347. 11.079 − . ± .
080 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
04 434. 11.048 − . ± .
061 0 . ± . < . ± .
03 0 . ± .
02 279. 5.332 0 . ± .
371 1 . ± . < < . ± .
02 209. 4.931 · · · · · ·
NGC 4254 Enuc. 1 E 12 18 46.77 +14 23 51.00 0 . ± .
03 0 . ± . < − . ± .
132 0 . ± . . ± . < < · · · · · · NGC 4254 12 18 49.54 +14 25 01.40 0 . ± .
06 0 . ± .
04 0 . ± .
05 559. 0.124 − . ± .
085 1 . ± . Table 4 continued Linden et al.
Table 4 (continued)
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)NGC 4254 Enuc. 1 D 12 18 50.03 +14 24 17.10 0 . ± .
04 0 . ± .
02 0 . ± .
04 349. 3.167 − . ± .
047 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
05 419. 3.924 0 . ± .
100 1 . ± . . ± . < . ± .
03 209. 2.953 − . ± .
110 0 . ± . . ± . < . ± .
03 347. 8.026 − . ± .
132 0 . ± . . ± .
03 1 . ± .
02 0 . ± .
03 277. 0.500 − . ± .
014 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 208. 0.514 − . ± .
024 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 208. 0.810 − . ± .
032 0 . ± . †
12 22 54.92 +15 49 21.00 23 . ± .
12 8 . ± .
09 5 . ± .
11 1040. 0.024 − . ± .
006 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 208. 0.069 − . ± .
013 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 277. 0.605 − . ± .
022 0 . ± . . ± .
03 1 . ± .
02 0 . ± .
03 277. 0.653 − . ± .
011 0 . ± . . ± .
03 1 . ± .
02 0 . ± .
03 277. 0.547 − . ± .
010 0 . ± . . ± .
02 0 . ± . < − . ± .
094 0 . ± . . ± .
03 12 . ± .
02 8 . ± .
03 281. 0.243 − . ± .
001 0 . ± . †
12 34 27.08 +02 11 17.30 88 . ± .
10 28 . ± .
06 16 . ± .
09 844. 0.030 − . ± .
001 0 . ± . . ± .
03 9 . ± .
02 6 . ± .
03 281. 0.330 − . ± .
001 0 . ± . . ± .
04 0 . ± . < − . ± .
245 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
03 203. 1.294 0 . ± .
100 1 . ± . < . ± . < · · · · · · NGC 4559 B 12 35 58.36 +27 57 33.90 0 . ± .
03 0 . ± .
02 0 . ± .
02 135. 0.599 0 . ± .
123 1 . ± . . ± .
02 0 . ± .
02 0 . ± .
01 102. 0.563 − . ± .
065 1 . ± . . ± .
07 1 . ± .
07 0 . ± .
08 430. 0.051 − . ± .
026 0 . ± . . ± .
13 2 . ± .
22 0 . ± .
18 795. 0.103 0 . ± .
060 1 . ± . . ± .
09 0 . ± .
06 0 . ± .
08 440. 0.046 − . ± .
061 1 . ± . . ± .
05 0 . ± .
04 0 . ± .
04 296. 13.669 0 . ± .
050 1 . ± . < . ± . < · · · · · · NGC 4631 A 12 42 03.59 +32 32 16.28 7 . ± .
03 2 . ± .
04 1 . ± .
04 148. 3.389 − . ± .
008 0 . ± . . ± .
03 1 . ± .
03 0 . ± .
04 148. 3.276 0 . ± .
019 1 . ± . . ± .
04 3 . ± .
04 3 . ± .
04 185. 1.712 − . ± .
006 0 . ± . . ± .
04 0 . ± .
04 0 . ± .
04 185. 4.464 − . ± .
029 0 . ± . . ± .
07 1 . ± .
05 1 . ± .
06 369. 6.825 − . ± .
026 1 . ± . < . ± . < · · · · · · NGC 4725 C 12 50 24.87 +25 29 22.80 0 . ± .
02 0 . ± . < − . ± .
136 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 173. 0.034 0 . ± .
078 1 . ± . . ± .
05 0 . ± . < . ± .
078 1 . ± . . ± .
05 0 . ± . < − . ± .
100 0 . ± . . ± .
05 0 . ± . < − . ± .
073 0 . ± . . ± . < < · · · · · · NGC 4736 L 12 50 50.030 +41 07 50.00 0 . ± . < < · · · · · · NGC 4736 H 12 50 50.045 +41 06 53.23 1 . ± .
05 1 . ± .
07 0 . ± .
10 136. 1.002 − . ± .
045 0 . ± . . ± . < < · · · · · · NGC 4736 F 12 50 51.201 +41 06 49.50 1 . ± .
05 0 . ± . < − . ± .
053 0 . ± . . ± .
05 1 . ± . < . ± .
117 1 . ± . . ± .
05 2 . ± .
06 1 . ± .
05 136. 0.020 − . ± .
013 0 . ± . . ± .
05 0 . ± .
07 0 . ± .
08 136. 0.914 0 . ± .
137 1 . ± . < . ± . < · · · · · · NGC 4736 P 12 50 54.541 +41 07 48.36 1 . ± .
05 0 . ± .
07 0 . ± .
10 136. 1.069 − . ± .
064 0 . ± . . ± .
05 1 . ± .
08 0 . ± .
11 136. 1.029 0 . ± .
061 1 . ± . . ± .
03 0 . ± .
05 0 . ± .
03 90. 0.869 0 . ± .
091 1 . ± . . ± .
05 1 . ± .
08 0 . ± .
04 136. 0.860 − . ± .
022 0 . ± . . ± .
05 1 . ± .
08 1 . ± .
05 136. 0.928 − . ± .
017 0 . ± . . ± .
05 1 . ± .
08 0 . ± .
07 136. 1.133 − . ± .
036 0 . ± . . ± . < . ± .
02 68. 1.033 0 . ± .
126 1 . ± . Table 4 continued
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 4 (continued)
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)NGC 4826 C 12 56 43.11 +21 40 54.79 0 . ± .
02 0 . ± .
02 0 . ± .
02 77. 0.427 − . ± .
028 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 77. 0.295 − . ± .
027 0 . ± . . ± .
04 4 . ± .
04 2 . ± .
04 153. 0.034 − . ± .
005 0 . ± . †
12 56 43.73 +21 41 00.90 10 . ± .
12 9 . ± .
12 3 . ± .
10 409. 0.049 − . ± .
009 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 77. 0.558 − . ± .
039 1 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 77. 0.250 − . ± .
029 0 . ± . . ± . < < · · · · · · NGC 5055 D 13 15 47.919 +42 01 41.96 0 . ± .
03 0 . ± . < − . ± .
104 1 . ± . . ± .
04 1 . ± .
03 0 . ± .
04 231. 0.054 − . ± .
022 0 . ± . . ± .
03 0 . ± . < − . ± .
057 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
03 231. 5.645 − . ± .
048 1 . ± . . ± .
06 0 . ± .
03 0 . ± .
02 222. 12.377 − . ± .
038 1 . ± . < . ± .
03 0 . ± .
03 222. 7.645 − . ± .
290 0 . ± . . ± .
08 0 . ± .
04 0 . ± .
03 259. 7.051 − . ± .
045 0 . ± . . ± . < . ± .
05 148. 5.358 0 . ± .
095 1 . ± . . ± . < . ± .
03 148. 4.942 − . ± .
063 0 . ± . < . ± .
03 0 . ± .
02 148. 4.365 0 . ± .
299 1 . ± . < . ± .
03 0 . ± .
02 148. 4.057 0 . ± .
422 1 . ± . . ± .
04 0 . ± .
03 0 . ± .
03 148. 5.220 − . ± .
068 0 . ± . . ± .
09 1 . ± .
06 0 . ± .
08 296. 1.968 − . ± .
034 0 . ± . . ± .
07 0 . ± .
04 0 . ± .
05 222. 1.450 − . ± .
044 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 111. 1.520 − . ± .
051 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 111. 4.641 − . ± .
077 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
03 148. 1.185 − . ± .
032 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 111. 4.592 − . ± .
073 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
03 148. 0.876 − . ± .
039 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
04 148. 1.045 − . ± .
025 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
03 148. 0.629 − . ± .
040 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 111. 0.777 − . ± .
079 0 . ± . . ± .
09 4 . ± .
05 1 . ± .
05 296. 0.379 − . ± .
008 0 . ± . . ± .
07 0 . ± . < . ± .
125 1 . ± . . ± .
03 1 . ± .
02 0 . ± .
02 111. 0.037 − . ± .
008 0 . ± . †
13 29 52.77 +47 11 40.90 10 . ± .
06 2 . ± .
03 1 . ± .
03 185. 0.082 − . ± .
007 0 . ± . . ± .
04 0 . ± .
02 0 . ± .
03 148. 2.368 − . ± .
071 0 . ± . < < . ± .
02 111. 5.873 · · · · · ·
NGC 5194 N 13 29 54.14 +47 11 27.40 1 . ± .
07 0 . ± . < − . ± .
098 0 . ± . . ± .
06 0 . ± .
03 0 . ± .
04 185. 1.412 − . ± .
053 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 111. 5.770 − . ± .
099 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
04 148. 2.119 − . ± .
066 0 . ± . < < . ± .
01 111. 6.690 · · · · · ·
NGC 5194 Enuc. 10 13 29 56.73 +47 10 45.70 0 . ± .
07 0 . ± .
04 0 . ± .
04 222. 2.829 − . ± .
063 0 . ± . . ± . < . ± .
02 111. 6.717 − . ± .
156 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
03 148. 7.776 − . ± .
100 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 111. 7.798 − . ± .
095 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
03 148. 7.726 − . ± .
064 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
04 185. 7.748 − . ± .
051 0 . ± . . ± .
06 0 . ± .
03 0 . ± .
04 185. 4.166 − . ± .
073 1 . ± . . ± .
04 0 . ± . < − . ± .
097 0 . ± . . ± .
07 0 . ± .
03 0 . ± .
05 222. 6.622 − . ± .
065 0 . ± . < . ± .
02 0 . ± .
04 148. 6.204 0 . ± .
250 1 . ± . . ± .
07 0 . ± .
03 0 . ± .
04 222. 6.591 − . ± .
065 0 . ± . . ± .
07 0 . ± .
03 0 . ± .
05 222. 6.301 − . ± .
047 0 . ± . . ± .
05 0 . ± .
02 0 . ± .
03 148. 6.369 − . ± .
077 0 . ± . Table 4 continued Linden et al.
Table 4 (continued)
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)NGC 5194 Enuc. 7 B 13 30 03.50 +47 09 41.14 0 . ± .
06 0 . ± . < − . ± .
146 0 . ± . . ± .
05 1 . ± . < − . ± .
010 0 . ± . . ± .
04 0 . ± . < − . ± .
141 0 . ± . . ± .
06 1 . ± .
03 1 . ± .
03 334. 1.417 − . ± .
013 0 . ± . . ± .
04 0 . ± .
04 0 . ± .
04 195. 15.711 − . ± .
028 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
03 162. 15.525 − . ± .
035 0 . ± . . ± .
05 1 . ± .
04 0 . ± .
05 227. 15.552 − . ± .
019 0 . ± . . ± .
03 0 . ± .
03 0 . ± .
03 130. 15.416 − . ± .
022 0 . ± . . ± .
03 0 . ± .
03 0 . ± .
04 130. 15.563 − . ± .
044 0 . ± . . ± .
02 0 . ± . < − . ± .
137 0 . ± . . ± .
02 0 . ± . < − . ± .
127 1 . ± . . ± .
02 0 . ± . < − . ± .
213 0 . ± . . ± .
03 1 . ± .
02 1 . ± .
02 130. 13.068 − . ± .
012 0 . ± . †
14 03 01.17 +54 14 26.90 2 . ± .
06 2 . ± .
04 1 . ± .
05 260. 13.180 − . ± .
017 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 130. 13.282 − . ± .
020 0 . ± . . ± . < . ± .
01 97. 0.756 − . ± .
109 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
03 195. 0.036 − . ± .
041 0 . ± . . ± .
03 0 . ± . < − . ± .
197 0 . ± . . ± .
03 0 . ± . < − . ± .
072 0 . ± . . ± .
04 0 . ± .
04 0 . ± .
05 162. 9.645 − . ± .
030 1 . ± . . ± .
07 9 . ± .
08 7 . ± .
08 292. 9.971 − . ± .
004 0 . ± . . ± .
04 0 . ± .
06 0 . ± .
07 195. 10.132 − . ± .
052 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
03 162. 12.097 − . ± .
061 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
03 162. 12.463 − . ± .
062 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
03 162. 12.530 − . ± .
029 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
03 162. 12.801 − . ± .
029 0 . ± . †
14 04 29.03 +54 23 48.80 5 . ± .
07 4 . ± .
07 3 . ± .
06 325. 23.774 − . ± .
008 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 97. 23.859 − . ± .
010 0 . ± . . ± .
03 0 . ± .
04 0 . ± .
03 415. 2.130 − . ± .
018 0 . ± . . ± .
02 0 . ± .
03 0 . ± .
02 311. 2.197 − . ± .
046 0 . ± . . ± .
02 1 . ± .
03 1 . ± .
02 311. 1.329 − . ± .
006 0 . ± . . ± .
05 0 . ± .
05 0 . ± .
04 623. 3.320 − . ± .
040 0 . ± . . ± .
04 1 . ± .
05 0 . ± .
03 519. 1.999 − . ± .
020 0 . ± . . ± .
02 1 . ± .
03 1 . ± .
02 311. 0.795 − . ± .
005 0 . ± . †
14 40 11.40 -00 17 20.10 11 . ± .
12 6 . ± .
14 2 . ± .
10 1556. 0.174 − . ± .
012 0 . ± . . ± .
02 3 . ± .
03 2 . ± .
02 311. 0.163 − . ± .
003 0 . ± . < . ± . < · · · · · · NGC 5713 E 14 40 12.74 -00 17 18.60 1 . ± .
04 0 . ± .
05 0 . ± .
04 519. 2.158 − . ± .
026 0 . ± . . ± .
05 4 . ± .
03 2 . ± .
03 297. 0.071 − . ± .
005 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 132. 9.282 0 . ± .
037 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 99. 9.172 0 . ± .
056 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
04 132. 9.199 0 . ± .
172 1 . ± . . ± .
05 0 . ± .
03 0 . ± .
05 198. 6.106 − . ± .
021 0 . ± . < < . ± .
02 99. 9.238 · · · · · ·
NGC 6946 Enuc. 8 B 20 34 37.489 +60 09 36.47 < . ± . < · · · · · · NGC 6946 Enuc. 5 B 20 34 39.31 +60 04 52.72 0 . ± .
04 0 . ± .
02 0 . ± .
02 165. 9.695 0 . ± .
059 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 132. 7.743 0 . ± .
118 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 132. 7.727 0 . ± .
108 1 . ± . . ± .
08 8 . ± .
05 4 . ± .
15 297. 0.041 − . ± .
004 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
03 198. 7.736 − . ± .
050 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
06 99. 0.857 − . ± .
046 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
05 99. 0.356 − . ± .
028 0 . ± . . ± .
03 0 . ± .
01 0 . ± .
03 99. 4.357 − . ± .
144 1 . ± . Table 4 continued
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 4 (continued)
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)NGC 6946 Enuc. 6 I 20 35 03.75 +60 10 59.40 0 . ± .
03 0 . ± .
01 0 . ± .
03 99. 4.524 − . ± .
091 0 . ± . . ± .
03 0 . ± .
01 0 . ± .
03 99. 4.457 − . ± .
087 0 . ± . . ± .
03 0 . ± .
01 0 . ± .
02 99. 4.659 − . ± .
089 0 . ± . < . ± .
02 0 . ± .
03 132. 5.295 0 . ± .
298 1 . ± . . ± .
03 0 . ± .
01 0 . ± .
03 99. 4.709 − . ± .
052 0 . ± . . ± .
03 0 . ± . < − . ± .
210 0 . ± . . ± .
03 0 . ± . < − . ± .
178 0 . ± . . ± .
04 0 . ± . < . ± .
132 1 . ± . . ± .
06 0 . ± .
03 0 . ± .
05 198. 5.111 − . ± .
039 0 . ± . . ± .
04 0 . ± .
02 0 . ± .
10 132. 5.374 − . ± .
059 0 . ± . . ± .
03 0 . ± .
01 0 . ± .
03 99. 5.054 0 . ± .
136 1 . ± . . ± .
03 0 . ± .
01 0 . ± .
02 99. 5.154 − . ± .
100 1 . ± . . ± .
05 0 . ± .
02 0 . ± .
04 165. 5.630 − . ± .
089 1 . ± . . ± .
03 0 . ± .
01 0 . ± .
03 99. 5.918 0 . ± .
114 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 132. 6.989 − . ± .
027 1 . ± . . ± .
03 0 . ± . < − . ± .
157 1 . ± . . ± . < < · · · · · · NGC 7331 F 22 37 02.52 +34 25 17.90 0 . ± .
05 0 . ± . < − . ± .
169 0 . ± . . ± .
07 1 . ± . < − . ± .
091 1 . ± . . ± .
06 1 . ± . < . ± .
062 1 . ± . . ± .
03 0 . ± . < . ± .
175 1 . ± . . ± . < . ± .
13 633. 3.053 − . ± .
118 0 . ± . . ± .
05 0 . ± . < . ± .
102 1 . ± . . ± .
03 0 . ± . < . ± .
170 1 . ± . . ± .
02 0 . ± . < − . ± .
188 0 . ± . . ± .
02 0 . ± . < − . ± .
083 1 . ± . . ± .
03 0 . ± . < − . ± .
232 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
04 95. 0.941 − . ± .
089 1 . ± . . ± .
04 0 . ± .
02 0 . ± .
04 152. 0.097 − . ± .
109 0 . ± . < . ± . < · · · · · · NGC 7793 Enuc. 1 C 23 57 51.10 -32 36 49.00 0 . ± .
02 0 . ± . < − . ± .
105 0 . ± . < < . ± .
05 171. 1.540 · · · · · ·
Likely Background GalaxiesNGC 0925 C 02 27 15.30 +33 35 28.60 1 . ± .
02 0 . ± .
02 0 . ± .
08 133. 3.375 − . ± .
020 0 . ± . . ± .
12 0 . ± . < − . ± .
122 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
02 44. 2.067 0 . ± .
078 1 . ± . . ± . < < · · · · · · NGC 2976 Enuc. 1 E 09 47 04.737 +67 56 41.47 0 . ± . < < · · · · · · NGC 3077 B 10 03 16.379 +68 43 42.53 0 . ± .
02 0 . ± . < . ± .
205 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 374. 0.082 − . ± .
015 0 . ± . . ± .
03 0 . ± . < − . ± .
194 0 . ± . . ± .
04 0 . ± . < − . ± .
222 0 . ± . . ± . < < · · · · · · NGC 4569 B 12 36 47.368 +13 10 27.07 0 . ± . < < · · · · · · NGC 4625 B 12 41 52.424 +41 17 17.64 0 . ± .
03 0 . ± .
02 0 . ± .
05 180. 2.434 − . ± .
043 0 . ± . . ± .
04 1 . ± .
03 0 . ± .
08 198. 8.611 − . ± .
012 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
10 165. 7.811 − . ± .
022 0 . ± . < . ± . < · · · · · · Table 4 continued Linden et al.
Table 4 (continued)
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)NGC 4736 B 12 50 52.026 +41 07 15.63 0 . ± . < < · · · · · · NGC 4736 C 12 50 52.522 +41 07 01.94 0 . ± . < < · · · · · · NGC 5194 D 13 29 55.79 +47 11 45.19 1 . ± .
06 0 . ± .
03 0 . ± .
05 185. 1.909 − . ± .
030 0 . ± . . ± .
05 0 . ± . < − . ± .
084 0 . ± . . ± .
04 0 . ± . < − . ± .
223 0 . ± . . ± .
04 0 . ± .
02 0 . ± .
04 132. 5.557 0 . ± .
078 1 . ± . . ± .
06 1 . ± .
04 1 . ± .
05 231. 8.572 0 . ± .
023 1 . ± . . ± .
07 1 . ± .
15 0 . ± .
15 562. 3.813 0 . ± .
065 1 . ± . . ± . < < · · · · · · Likely AME CandidatesNGC 2403 Enuc. 5 D 07 36 20.57 +65 37 08.50 0 . ± .
03 0 . ± .
02 0 . ± .
02 62. 3.362 − . ± .
022 1 . ± . . ± .
03 0 . ± .
03 1 . ± .
08 62. 2.684 − . ± .
019 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 62. 2.637 0 . ± .
039 1 . ± . . ± .
03 1 . ± .
02 1 . ± .
03 62. 2.921 − . ± .
007 0 . ± . . ± .
03 0 . ± .
05 0 . ± .
13 182. 7.171 0 . ± .
067 1 . ± . . ± .
05 0 . ± .
08 0 . ± .
30 273. 7.467 0 . ± .
094 1 . ± . . ± .
03 0 . ± .
03 0 . ± .
02 279. 4.669 0 . ± .
109 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 279. 4.437 − . ± .
059 0 . ± . . ± .
03 0 . ± .
03 1 . ± .
03 148. 1.354 − . ± .
012 0 . ± . . ± .
03 0 . ± .
03 0 . ± .
03 148. 1.525 − . ± .
015 0 . ± . . ± .
02 0 . ± .
03 0 . ± .
03 111. 1.740 − . ± .
016 0 . ± . . ± .
04 3 . ± .
05 3 . ± .
06 222. 1.366 − . ± .
006 0 . ± . . ± .
04 0 . ± .
02 0 . ± .
02 185. 9.993 − . ± .
034 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
02 173. 1.930 0 . ± .
052 1 . ± . . ± .
08 0 . ± .
03 0 . ± .
04 259. 6.852 − . ± .
035 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
05 148. 2.587 0 . ± .
045 1 . ± . . ± .
05 0 . ± .
02 0 . ± .
03 148. 2.327 0 . ± .
043 1 . ± . . ± .
04 0 . ± .
02 0 . ± .
02 148. 6.192 − . ± .
031 0 . ± . . ± .
04 0 . ± .
02 0 . ± .
03 162. 6.429 − . ± .
052 1 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 97. 23.668 − . ± .
013 0 . ± . . ± .
03 1 . ± .
03 1 . ± .
02 130. 23.894 − . ± .
006 0 . ± . . ± .
03 1 . ± .
02 1 . ± .
02 132. 9.032 0 . ± .
009 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 132. 8.808 − . ± .
043 1 . ± . . ± .
03 1 . ± .
02 1 . ± .
03 132. 8.741 − . ± .
013 1 . ± . . ± .
05 0 . ± .
03 1 . ± .
11 165. 0.972 0 . ± .
040 1 . ± . . ± .
04 0 . ± .
02 0 . ± .
07 132. 0.601 0 . ± .
058 1 . ± . . ± .
04 0 . ± .
02 0 . ± .
10 132. 5.163 − . ± .
088 0 . ± . . ± .
03 0 . ± .
01 0 . ± .
02 99. 4.894 − . ± .
021 0 . ± . . ± .
03 0 . ± .
01 0 . ± .
02 99. 4.801 − . ± .
025 0 . ± . †
20 35 06.24 +60 10 58.32 1 . ± .
05 1 . ± .
03 1 . ± .
05 198. 4.876 − . ± .
019 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
08 132. 5.374 − . ± .
039 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
04 132. 8.130 0 . ± .
112 1 . ± . . ± .
02 0 . ± . < − . ± .
122 0 . ± . Note — † The aperture used for this region contained multiple smaller individual regions.
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 5 . Region Photometry and Derived Parameters at 7 (cid:48)(cid:48)
Angular Resolution
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)Star-Forming RegionsNGC 0337 a 00 59 50.018 -07 34 33.9 0 . ± .
02 0 . ± .
01 0 . ± .
01 655. 0.945 − . ± .
03 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
02 655. 1.966 − . ± .
02 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
02 655. 3.227 − . ± .
07 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
02 655. 4.061 − . ± .
04 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 244. 7.608 − . ± .
04 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 244. 4.468 − . ± .
03 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
02 244. 5.720 − . ± .
03 0 . ± . < < < · · · · · · NGC 0628 Enuc. 1 01 36 45.266 +15 47 48.3 0 . ± .
02 0 . ± .
01 0 . ± .
02 244. 2.478 − . ± .
02 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 330. 0.202 − . ± .
02 0 . ± . . ± .
01 0 . ± . < − . ± .
14 0 . ± . < < < · · · · · · NGC 1097 02 46 18.984 -30 16 28.8 5 . ± .
18 2 . ± .
08 2 . ± .
09 482. 0.020 − . ± .
02 0 . ± . < . ± .
01 0 . ± .
02 482. 5.416 − . ± .
41 1 . ± . . ± . < . ± .
02 482. 6.817 − . ± .
11 0 . ± . < < . ± .
02 482. 7.392 · · · · · ·
NGC 1266 03 16 00.76 -02 25 37.1 23 . ± .
70 6 . ± .
21 4 . ± .
13 1038. 0.270 − . ± .
02 0 . ± . < < < · · · · · · NGC 1482 03 54 38.966 -20 30 07.8 33 . ± .
01 9 . ± .
29 6 . ± .
21 767. 0.124 − . ± .
02 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 109. 5.380 − . ± .
02 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 109. 1.087 − . ± .
04 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 109. 1.192 − . ± .
02 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 109. 1.113 − . ± .
03 0 . ± . < < < · · · · · · NGC 2403 Enuc. 2 b 07 36 52.361 +65 36 46.9 0 . ± .
02 0 . ± .
02 0 . ± .
02 109. 1.249 − . ± .
02 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 109. 3.455 − . ± .
02 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 104. 0.738 0 . ± .
04 1 . ± . . ± .
46 5 . ± .
17 2 . ± .
06 876. 0.144 − . ± .
02 0 . ± . . ± .
03 0 . ± .
03 0 . ± .
02 479. 0.155 − . ± .
02 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
02 120. 1.420 − . ± .
02 0 . ± . . ± .
04 1 . ± .
03 0 . ± .
03 120. 1.201 − . ± .
02 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 120. 0.462 − . ± .
07 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 120. 1.394 − . ± .
02 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
02 120. 1.310 − . ± .
03 0 . ± . . ± .
04 0 . ± .
02 0 . ± .
02 652. 0.103 − . ± .
02 0 . ± . . ± .
11 2 . ± .
07 1 . ± .
06 130. 0.045 − . ± .
02 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
01 655. 0.098 − . ± .
02 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 397. 0.063 − . ± .
03 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 479. 0.116 − . ± .
03 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
02 129. 6.253 − . ± .
03 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 129. 5.254 − . ± .
03 1 . ± . . ± .
06 0 . ± .
02 0 . ± .
02 665. 0.087 − . ± .
02 0 . ± . . ± .
09 1 . ± .
04 0 . ± .
03 317. 0.230 − . ± .
02 0 . ± . . ± .
10 1 . ± .
04 0 . ± .
03 317. 0.258 − . ± .
02 0 . ± . . ± .
02 0 . ± . < . ± .
21 1 . ± . < . ± . < · · · · · · NGC 3521 11 05 48.9 -00 02 06 < < < · · · · · · NGC 3521 Enuc. 2 a 11 05 49.34 -00 03 24.2 0 . ± .
02 0 . ± .
02 0 . ± .
03 380. 4.302 − . ± .
07 0 . ± . Table 5 continued Linden et al.
Table 5 (continued)
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)NGC 3521 Enuc. 2 b 11 05 49.94 -00 03 55.9 < < . ± .
03 380. 6.044 · · · · · ·
NGC 3621 11 18 16 -32 48 42 0 . ± . < < · · · · · · NGC 3627 11 20 15 +12 59 29.4 4 . ± .
14 1 . ± .
05 1 . ± .
04 318. 0.028 − . ± .
02 0 . ± . . ± .
04 1 . ± .
03 0 . ± .
03 318. 4.712 − . ± .
02 0 . ± . . ± .
14 2 . ± .
08 1 . ± .
06 318. 2.746 − . ± .
02 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 421. 0.023 − . ± .
02 0 . ± . < < . ± .
01 607. 1.407 · · · · · ·
NGC 3938 a 11 52 49.5 +44 07 14 < < < · · · · · · NGC 3938 Enuc. 2 a 11 53 00.056 +44 08 00 0 . ± .
01 0 . ± .
01 0 . ± .
01 607. 11.158 0 . ± .
07 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 607. 11.049 − . ± .
05 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 489. 5.342 0 . ± .
12 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 489. 4.698 0 . ± .
08 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 489. 1.553 − . ± .
07 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 489. 0.111 − . ± .
05 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 489. 3.886 0 . ± .
07 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 489. 0.960 0 . ± .
13 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 489. 3.116 − . ± .
03 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
02 489. 2.344 − . ± .
05 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
02 489. 2.813 0 . ± .
08 1 . ± . . ± . < . ± .
02 489. 3.149 0 . ± .
14 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 485. 8.305 − . ± .
10 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 485. 7.979 − . ± .
10 0 . ± . < < . ± .
01 485. 7.285 · · · · · ·
NGC 4321 a 12 22 54.651 +15 49 19.8 2 . ± .
06 0 . ± .
03 0 . ± .
02 485. 0.284 − . ± .
02 0 . ± . . ± .
09 1 . ± .
03 0 . ± .
02 485. 0.270 − . ± .
02 0 . ± . < < < · · · · · · NGC 4536 12 34 27.06 +02 11 18.2 21 . ± .
64 7 . ± .
23 4 . ± .
15 492. 0.126 − . ± .
02 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 237. 1.304 − . ± .
08 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 237. 1.880 0 . ± .
12 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 237. 0.608 0 . ± .
06 1 . ± . . ± .
09 0 . ± .
03 0 . ± .
02 335. 0.037 − . ± .
02 0 . ± . . ± .
64 24 . ± .
73 30 . ± .
92 557. 0.105 0 . ± .
02 1 . ± . . ± .
17 45 . ± .
36 36 . ± .
10 308. 0.052 − . ± .
02 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 259. 13.762 − . ± .
04 1 . ± . < . ± .
01 0 . ± .
01 316. 0.139 − . ± .
39 0 . ± . . ± .
11 1 . ± .
03 0 . ± .
03 259. 3.189 − . ± .
02 0 . ± . . ± .
05 1 . ± .
03 0 . ± .
02 259. 3.435 − . ± .
02 0 . ± . . ± .
07 1 . ± .
04 1 . ± .
04 259. 1.734 − . ± .
02 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 259. 4.988 − . ± .
03 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 259. 1.387 − . ± .
02 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 6.651 − . ± .
02 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 404. 0.044 0 . ± .
07 1 . ± . . ± .
12 1 . ± .
05 1 . ± .
03 158. 0.014 − . ± .
02 0 . ± . . ± .
02 0 . ± .
03 0 . ± .
02 158. 0.864 − . ± .
02 0 . ± . . ± .
03 0 . ± .
03 0 . ± .
02 158. 0.939 − . ± .
02 0 . ± . . ± .
02 0 . ± .
03 0 . ± .
02 158. 1.123 − . ± .
03 0 . ± . . ± .
13 1 . ± .
05 1 . ± .
03 179. 0.055 − . ± .
02 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 269. 0.009 − . ± .
03 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 269. 5.630 − . ± .
04 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 12.321 − . ± .
03 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 7.048 − . ± .
03 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 4.941 − . ± .
04 0 . ± . < . ± .
01 0 . ± .
01 259. 4.340 − . ± .
17 0 . ± . Table 5 continued
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 5 (continued)
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)NGC 5194 Enuc. 11 d 13 29 49.582 +47 13 28.7 < . ± .
01 0 . ± .
01 259. 4.078 0 . ± .
34 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 5.221 − . ± .
05 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
01 259. 1.804 − . ± .
03 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 259. 4.633 − . ± .
04 0 . ± . . ± .
04 0 . ± .
02 0 . ± .
01 259. 0.977 − . ± .
02 0 . ± . . ± .
10 1 . ± .
04 0 . ± .
02 259. 0.365 − . ± .
02 0 . ± . . ± .
14 1 . ± .
04 0 . ± .
02 259. 0.092 − . ± .
02 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 2.323 − . ± .
04 0 . ± . < < . ± .
01 259. 5.880 · · · · · ·
NGC 5194 Enuc. 10 a 13 29 55.346 +47 10 47.199 0 . ± .
02 0 . ± .
01 0 . ± .
01 259. 2.336 − . ± .
07 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 259. 5.798 − . ± .
05 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
02 259. 1.906 − . ± .
03 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 2.723 − . ± .
04 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 259. 7.696 − . ± .
06 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 7.742 − . ± .
04 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 4.131 0 . ± .
04 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
02 259. 6.221 0 . ± .
11 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 6.650 − . ± .
03 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 6.329 − . ± .
03 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 6.962 − . ± .
08 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 260. 1.381 − . ± .
02 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 227. 15.707 − . ± .
02 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 227. 15.550 − . ± .
02 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 227. 15.422 − . ± .
02 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 227. 13.129 − . ± .
02 0 . ± . . ± . < . ± .
01 227. 0.744 − . ± .
07 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 227. 0.062 − . ± .
03 0 . ± . . ± .
02 0 . ± . < − . ± .
10 0 . ± . . ± .
02 0 . ± .
03 0 . ± .
03 227. 9.655 − . ± .
03 1 . ± . . ± .
13 3 . ± .
10 2 . ± .
09 227. 9.964 − . ± .
02 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
03 227. 10.113 − . ± .
05 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 227. 12.149 − . ± .
04 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 227. 12.453 − . ± .
04 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 227. 12.540 − . ± .
02 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 227. 12.795 − . ± .
02 0 . ± . < < < · · · · · · NGC 5713 Enuc. 2 a 14 40 10.8 -00 17 35.5 0 . ± .
03 0 . ± .
02 0 . ± .
01 726. 1.984 − . ± .
02 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
01 726. 3.295 − . ± .
04 0 . ± . . ± .
04 0 . ± .
03 0 . ± .
01 726. 0.795 − . ± .
02 0 . ± . . ± .
17 2 . ± .
07 1 . ± .
04 726. 0.313 − . ± .
02 0 . ± . . ± .
17 3 . ± .
11 2 . ± .
06 519. 0.051 − . ± .
02 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 231. 8.739 − . ± .
02 1 . ± . . ± .
04 0 . ± .
02 0 . ± .
02 231. 6.122 − . ± .
02 0 . ± . < < . ± .
01 231. 9.239 · · · · · ·
NGC 6946 Enuc. 5 b 20 34 39.361 +60 04 52.4 0 . ± .
01 0 . ± .
01 0 . ± .
01 231. 9.704 0 . ± .
04 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 231. 7.742 0 . ± .
09 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 231. 7.729 − . ± .
03 1 . ± . . ± .
60 8 . ± .
26 5 . ± .
17 231. 0.016 − . ± .
02 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 231. 4.728 − . ± .
04 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 231. 5.071 − . ± .
02 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 231. 5.637 0 . ± .
03 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 231. 6.989 − . ± .
03 1 . ± . . ± .
01 0 . ± . < . ± .
18 1 . ± . Table 5 continued Linden et al.
Table 5 (continued)
Source ID R.A. Decl. S S
15 GHz S
33 GHz d ap r G α f
33 GHzT (J2000) (J2000) (mJy) (mJy) (mJy) (pc) (kpc)NGC 7793 Enuc. 1 23 57 48.8 -32 36 57.991 0 . ± .
01 0 . ± . < − . ± .
25 0 . ± . . ± .
01 0 . ± . < − . ± .
09 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 133. 0.174 − . ± .
14 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 133. 0.081 − . ± .
09 0 . ± . < < < · · · · · · Likely Associated with SupernovaeNGC 6946 Enuc. 6 a 20 35 06.08 +60 10 58.5 0 . ± .
02 0 . ± .
01 0 . ± .
02 231. 4.855 − . ± .
02 0 . ± . . ± .
02 0 . ± .
02 0 . ± .
02 109. 3.464 − . ± .
02 1 . ± . . ± .
06 1 . ± .
05 1 . ± .
05 109. 2.811 − . ± .
02 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 489. 4.428 − . ± .
04 0 . ± . . ± .
03 0 . ± .
01 0 . ± .
02 259. 1.566 − . ± .
02 0 . ± . . ± .
05 0 . ± .
03 0 . ± .
03 259. 0.960 − . ± .
02 0 . ± . . ± .
06 0 . ± .
03 1 . ± .
04 259. 1.769 − . ± .
02 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 259. 9.974 − . ± .
03 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 404. 1.921 0 . ± .
06 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 6.834 − . ± .
02 0 . ± . . ± .
02 0 . ± .
01 0 . ± .
02 259. 2.534 0 . ± .
03 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 2.322 − . ± .
03 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
01 259. 6.193 − . ± .
03 0 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 227. 6.451 − . ± .
04 1 . ± . . ± .
07 1 . ± .
03 1 . ± .
03 227. 23.861 − . ± .
02 0 . ± . . ± .
03 0 . ± .
02 0 . ± .
03 231. 9.044 − . ± .
02 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 231. 8.801 0 . ± .
05 1 . ± . . ± .
02 0 . ± .
01 0 . ± .
03 231. 1.004 0 . ± .
03 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
03 231. 0.601 0 . ± .
04 1 . ± . . ± .
01 0 . ± .
01 0 . ± .
01 231. 8.120 0 . ± .
08 1 . ± . . ± .
03 0 . ± .
02 0 . ± .
02 231. 8.595 − . ± .
02 0 . ± . RESULTSUsing the 3, 15, and 33 GHz photometry, along withthe 8 µ m imaging from Spitzer , we classify each region aseither a star-forming region (SF), a background galaxycandidate (BG), a likely supernova remnant (SNe/R: seeSection 5.4), or an anomalous microwave emission candi-date (AME: see Section 5.5). In total we have identified320 star-forming regions, 14 likely background galaxies,10 likely supernovae/supernova remnants, and 33 AMEcandidates. Given that we are primarily interested inemission arising from our sample galaxies, the potentialbackground galaxies have been removed from all plots,and are discussed as a separate population of sourcesin Section 5.3. Regions identified at 7 (cid:48)(cid:48) which includeemission from potential AME and SNe/R candidates arecorrespondingly classified in Table 5.We present results for the spectral index and thermalfraction distributions only including regions identified in the SFRS that have a
S/N ≥ S/N of these 335 sources is 18, 15, and 9for detections at 3, 15, and 33 GHz, respectively.We apply the same criteria for sources included in thespectral index and thermal fraction analysis using the7 (cid:48)(cid:48) smoothed images. This removes 17 star-forming re-gions. These single-band detections are also distributed
FRS: 3 - 33 GHz Imaging of Star-Forming Regions
S/N of these 163 sourcesis 24, 23, and 19 for detections at 3, 15, and 33 GHz,respectively. 4.1.
Spectral Indices
The simplest approach to modeling the radio spec-tra of galaxies is by adopting a two-component power-law, with the thermal/nonthermal ratio as well as thenon-thermal spectral index allowed to vary as free pa-rameters. For many star-forming galaxies in the localUniverse, this model adequately describes the dominantphysical processes occurring at radio frequencies (Con-don 1992). However, a robust interpretation of the radiospectrum can be complex. For example: the thermaland nonthermal fractions may vary with galaxy mass(e.g. Hughes et al. 2007; Bell 2003), the nonthermal in-dex can vary within galaxies (Tabatabaei et al. 2017),and AME may add an additional component to the radiospectra at high frequencies in some regions (e.g. Murphyet al. 2010, 2018b).To measure the 3 −
33 GHz spectral indices, we per-formed a linear least-squares fit to the data with a singlepower-law representing the combination of thermal andnonthermal emission. The distributions of the measuredspectral slopes with the 10 likely background galaxiesremoved are given in the top panel of Figure 2 (325 to-tal regions). The median spectral indices we measurefrom 3 −
15, 15 −
33, and 3 −
33 GHz are − . ± . − . ± . − . ± . −
15 GHz, in-dicating that the contribution of non-thermal emissionto the radio flux density of individual star-forming re-gions is marginal on ∼
100 pc scales in these galaxies.This is consistent with the results presented in Murphyet al. (2012), where they show that the thermal fractionat 33 GHz increased as function of decreasing linear res-olution. Despite the relatively flat spectral slopes from3 −
15 GHz, we do see evidence that the spectrum con-tinues to flatten from 15 −
33 GHz, on average. Thisis consistent with expectations for star-forming regions,where the radio spectrum is synchrotron-dominated atlow frequencies, and flattens at higher frequencies asthe contribution of thermal emission increases (Condonet al. 2012; Clemens et al. 2010; Murphy et al. 2013). Fi-nally, we do not see any significant evidence for free-freeabsorption, which is known to affect the compact cen-
Figure 2.
Top: The 3 −
15 GHz (black), 15 −
33 GHz (green),and 3 −
33 GHz (purple) radio spectral index distributions for325 regions identified in the SFRS. The median size of theapertures used is 162 ± . (cid:48)(cid:48) regions identified in M18a. The me-dian size of the apertures used at 7 (cid:48)(cid:48) resolution is 259 ± . −
33 GHz distributions measuredat ∼ (cid:48)(cid:48) and 7 (cid:48)(cid:48) are consistent with one another, implyingthat free-free emission dominates the radio spectra of star-forming regions on scales up to ∼ Linden et al. tral regions of local star-forming and starburst galaxies,and would result in steep spectral indices even at highfrequencies (Condon & Yin 1990; Clemens et al. 2008;Murphy et al. 2013).In the nearby Universe, the typical radio spectrumof normal star-forming galaxies is well-described by apower-law spectrum with a spectral index of − .
7, anda thermal fraction of ∼
10% at ∼ Thermal Fractions
Given the results above, we now calculate the ther-mal fraction of each region by using the spectral index,measured in Section 4.1, from 3 −
15 GHz ( α −
15 GHz )to set the lower-limit on the nonthermal spectral index( α NT ) such that α NT = − .
83 if α −
15 GHz ≥ − . α NT = α −
15 GHz if α − GHz < − .
83. A con-stant nonthermal radio spectral index of − .
83 is as-sumed based on the average non-thermal spectral in-dex found among the 10 star-forming regions studied inNGC 6946 by Murphy et al. (2011). Furthermore, thisvalue is consistent with the results of Niklas & Beck(1997, i.e., α NT = − .
83 with a scatter of σ α NT = 0 . ∼ − . f ν T = ( ν ν ) − α − ( ν ν ) − α NT ( ν ν ) − . − ( ν ν ) − α NT (1)where ν is the target frequency (33 GHz), α is the ob-served slope from 3 to 33 GHz, and α NT is the non-thermal spectral index. In the top Panel of Figure 3 weshow the resulting thermal fractions of the star-formingregions in our sample using the empirically measuredvalues from Equation 1. We find that the median valueis 92 ± .
8% with a median absolute deviation of 11%.This demonstrates that we can reliably use the 33 GHzflux density to infer the total free-free emission, and thuscurrent star formation activity, on the scales of individ- ual H ii and star-forming regions. While this result hadbeen suggested by our previous GBT and VLA cam-paigns (e.g., Murphy et al. 2011, 2012, 2018a), this isthe first measurement of the 33 GHz thermal fractionbased on the shape of the radio spectrum at these fre-quencies and spatial scales in nearby galaxies.Further, by restricting our analysis such that we re-move all non-SF regions, all apertures containing multi-ple smaller individual regions, and require r G ≥ ii regions using our cleanest sample ofextranuclear star-forming regions. In Figure 4 we findthat the median thermal fraction is 93 ± .
8% with amedian absolute deviation of 10%. This value is con-sistent with the results presented in Figures 2, and 3,and confirms that supernova remnants, ultra-compactH ii regions, and/or AME candidates do not bias ourresults.Finally, we measure the thermal fraction at 33 GHzfor 163 regions identified at 7 (cid:48)(cid:48) resolution in M18a tobe 94 ± .
8% with a median absolute deviation of 8%.This result is consistent with the measurements at 2”and confirms that free-free emission dominates the ra-dio spectra of star-forming regions on scales up to ∼ r G > ± .
5% with a median absolute deviationof 4 . MCMC Parameter Estimation
From Equation 1 it is clear that reliable estimates forthe 33 GHz thermal fraction are sensitive to the valueadopted for the nonthermal spectral index ( α NT ). Whilethe median 3 −
15 GHz spectral index observed for oursample is well below the canonical value (i.e., − . α NT and f T . Inthis case classical χ fitting methods may underesti-mate the true uncertainties associated with modelingthe radio spectrum as a two-component power-law [i.e., S ( ν ) = Aν α NT + Bν − . ]. Here, we explore whetherthe marginalized posterior distributions from a Monte-Carlo Markov Chain (MCMC) analysis better reflect theuncertainties associated with this decomposition (Hogget al. 2010).For this exercise, we use the Python package em-cee (Foreman-Mackey et al. 2013) to generate posterior FRS: 3 - 33 GHz Imaging of Star-Forming Regions Figure 3.
Top: The thermal fraction distribution at 33 GHzfor 325 star-forming regions in the SFRS (black). In purplewe show the distribution for regions with a
S/N ≥ ± . (cid:48)(cid:48) regions identified in M18a witha S/N > (cid:48)(cid:48) resolution is 259 ± . ∼ ∼ probability distributions for each of the fitted parame-ters ( α NT , f T , and A/B ) given the typical
S/N ratio ofour three-band observations. Following Westcott et al.(2018), we parameterize our two-component power-lawmodel at a reference frequency of 1 GHz to avoid depen-dencies in frequency space. Further, we adopt a gaus-sian probability distribution function for the nonthermalspectral index whose mean and standard deviation areconsistent with the values obtained in Niklas & Beck(1997). Finally, we make a slight modification to Equa-tion 9 presented in Westcott et al. (2018), P ( θ ) ∝ H ( A, B ) e − ( α − . . (2)such that H is equal to 1 when the values of A and B aregreater than zero. This is done in order to constrain thenonthermal spectral index, thermal fraction, and nor-malization constants of each component simultaneously.We make 1000 realizations of this model at three differ-ent S/N ratios (5, 10, and 50) by randomly selecting anonthermal spectral index ( − < α NT <
0) and vales ofA(B) [0 < A ( B ) < S/N per region of10, and with only three data points, our MCMC mod-eling can recover the input nonthermal spectral indexto within 1 σ for − . < α NT < .
25. Importantly, wefind that the best-constrained spectra have nonthermalindices very close to the fixed-value adopted for our χ -minimization ( − . α NT does not introducesystematic biases into the derived 33 GHz thermal frac-tions, over a reasonable set of input conditions for ourtwo-component power-law model. This is an importantresult for calibrations of the total star-formation rate,which rely on using the observed radio continuum (Mur-phy et al. 2011, 2012). DISCUSSION5.1.
Trends with Galactocentric Radius
Following the same procedure as M18a, we use themeasured position angle (PA) and inclination of eachgalaxy to convert the angular separation of each star-forming region from the nucleus into a de-projectedgalactocentric radius ( r G ). In M18a we found that themedian 33 GHz continuum-to-H α line flux ratio was sta-tistically larger within r G <
250 pc relative to the outerdisk regions by a factor of 1 . ± .
39, while the ratioof 33 GHz-to-24 µ m flux densities is lower by a factor of0 . ± .
08. Such a situation may arise if the circum-4
Linden et al.
Figure 4.
The spectral index and thermal fraction distributions for all 238 SF regions with the likely supernova remnants andAME candidates removed, and a requirement of r G ≥ ii regions.Ultimately we find that the median spectral index and thermal fraction distributions at 33 GHz are consistent with the resultspresented in Figures 2 and 3, confirming that supernova remnants, ultra-compact H ii regions, and AME candidates do not biasour results. nuclear regions of these galaxies have extended star for-mation histories in which star formation that has takenplace over a longer period of time, resulting in an ac-cumulation of young dust-heating stars in addition tomuch older bulge stars that boost the 24 µ m flux den-sity relative to what is seen in the extranuclear regions.This is largely opposite to what we would expect if therewas an additional nonthermal component powering the33 GHz emission in the central regions of these galaxies,unless the excess dust-heating at 24 µ m far exceeds anyadditional nonthermal emission contribution at 33 GHz.Therefore, these results suggested that the larger ratioof 33 GHz flux density to H α line flux found in the cen-tral regions of these galaxies may primarily arise fromincreased extinction. We can now test this picture for325 discrete regions (background galaxies removed) withdetailed radio spectral fitting and thermal fraction esti-mates, which do not suffer from the effects of variabledust extinction in galaxies. In Figure 6 it is clear thatthe overall dispersion in the measured spectral index andthermal fraction at 33 GHz increases significantly for re-gions that lie within the 250 pc galactocentric radiuscut used in M18a to distinguish extranuclear from nu-clear/circumnuclear star-forming regions. In fact, lim-iting the analysis to sources with r G <
250 pc resultsin a value for the median 33 GHz thermal fraction of ∼ ± .
5% with a median absolute deviation of ∼
18% relative to ∼ ± .
2% with a median absolute devia-tion of ∼
11% for regions with r G ≥
250 pc. Addition-ally, the scatter of the thermal fraction distribution in-creases by nearly a factor of 2 within r G < Model Age Fitting
By making use of differences in the timescales associ-ated with thermal (free-free) and synchrotron emission,we can place estimates on the age of star-forming re-gions by examining how these processes affect the radiospectral indicex from 3 −
33 GHz. Since free-free emis-sion is directly associated with ionizing photons that areonly produced by the shortest-lived ( ≤
10 Myr) massivestars, its presence in large quantities relative to syn-chrotron emission is indicative of very young star for-mation.To better-quantify these different timescales, we usea Starburst 99 (SB99) model of a single instanta-neous burst with default inputs (solar metallicity and2-component Kroupa IMF) run for 1 Gyr (Leithereret al. 1999). However, in order to take into account thefact that at the median physical scales we are probing,( ∼
100 pc), a single, instantaneous starburst may not
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Figure 5.
The results from our MCMC analysis of 1000random realizations of 3 - 33 GHz spectra using as a model S ( ν ) = Aν α NT + Bν − . . For these realizations we fix S/N =10 and vary the thermal fraction at 33 GHz by randomlyassigning a non-thermal spectral index from 0 to 2, and an A(B) values between 0 and 1. It is clear from this exercise thatby fitting our data using an MCMC approach, our ability torecover the true value for the 33 GHz thermal fraction peaksat α NT , in ∼ − .
8, which closely resembles the canonical valuefor the nonthermal spectral index. be representative, we also include SB99 models with acontinuous star formation history of SFR = 1 M (cid:12) yr − using the same metallicity and IMF input as in the in-stantaneous burst model (Figure 7 - Left Panel). Thedetails of these models, and their application to ex-tranuclear star-forming regions identified in LIRGs ispresented in Linden et al. (2019).For both models we then perform a χ minimizationto the observed spectral indices for each star-formingregion in the sample. We stress that without includingcosmic-ray propagation, which will affect the relative ra-tio of free-free and non-thermal emission on these scales,this exercise is simply meant to understand how the ob-served distribution of spectral indices can be representedas a distribution of ages. In the left panel of Figure 7 it isclear that our models are insensitive to H ii regions withages τ Hii < τ Hii >
40 Myr. However, in theintermediate age range we find that a typical uncertaintyof 4 −
6% on the observed spectral index corresponds to a0 . − . < τ Hii <
10 Myr) relative toold ( τ Hii ∼ −
30 Myr) star-forming regions is robust. The right panel of Figure 7 shows the distribution offitted ages for the instantaneous burst model in blue andthe continuous model in green. Overall, we find that themajority ( ∼ ∼
10 Myr (greydistribution). Further we find that when all regionsare modeled using a continuous SFH, an age-gradientemerges in Figure 6. At small r G , the regions with lowthermal fractions, which drive the observed scatter, arepreferentially older ( τ Hii ∼ −
30 Myr). This furthersupports the notion that the central star-forming regionsare, on average, older, and that the associated cosmicray population in the inner disk of these galaxies is be-ing continuously replenished by ongoing star-formation.5.3.
Likely Background Galaxies
For the 10 likely background sources (BG) identified(i.e. sources with no obvious 8 µ m counterpart), whichhave a S/N ≥ −
33 GHz spectral index is − . ± .
04 witha median absolute deviation of 0.3. This value is sig-nificantly steeper than the average value measured forthe SF regions, and indicates that these sources are pri-marily dominated by synchrotron emission. This resultfurther suggests that our visual classification scheme in-volving both radio and near-IR imaging appears to be aneffective discriminator for various types of radio sourcesin surveys of nearby galaxies. Finally, a cross-referencewith NED suggests that none of these sources have beenpreviously identified in the literature.5.4.
Supernova and Supernova Remnants
In order to identify possible supernova remnants, wecross-correlated our sample of 377 regions against theOpen Supernova Catalog (OSC: Guillochon et al. 2017).In total we identify 6 sources as being spatially coinci-dent (within 2 (cid:48)(cid:48) ) to an identified radio source with a
S/N ≥ −
33 GHzspectral slopes measured are uniformly distributed from − Anomalous Microwave Emission
Anomalous Microwave Emission (AME) is a knowndust-correlated component of Galactic emission that hasbeen detected by cosmic microwave background (CMB)6
Linden et al.
Figure 6.
The spectral index and 33 GHz thermal fraction distributions plotted against galactocentric radius for all 325sources identified in Figure 2. While we identify regions across the full extent of galaxy disks which are heavily dominated bythermal emission, a clear trend emerges where the scatter in both quantities increases significantly as a function of decreasinggalactocentric radius (orange points). In particular, no region with a measured f T <
80% is found in any SFRS galaxy beyonda radius of 7 kpc. These trends are reflective of the ongoing star-formation activity occurring in the centers of nearby normalgalaxies, and reinforce our ability to successfully capture the SFH of individual H ii regions using the 3 −
33 GHz radio spectralslopes. experiments and other radio/microwave instruments atfrequencies 10 −
60 GHz since the mid-1990s (see Dick-inson et al. 2018, and articles within for recent reviews).AME is found to be spatially correlated with far-infraredthermal dust emission, but cannot be explained by syn-chrotron, or free-free emission mechanisms, and is farin excess of the emission contributed by thermal dustwith the power-law opacity consistent with observationsat sub-mm wavelengths. The most natural explana-tion for AME is rotational (electric dipole) emissionfrom ultra-small dust grains (i.e., ‘spinning dust’: Er-ickson 1957; Draine & Lazarian 1998). The emissionforms part of the diffuse Galactic foregrounds that con-taminate CMB data, which operate in the frequencyrange 30 −
300 GHz, and hence knowledge of the spatialstructure and spectral shape can inform CMB compo-nent separation. However, spinning dust emission de- pends critically on the dust grain size distribution, thetype of dust, and the environmental conditions (density,temperature, interstellar radiation field, etc.). Thus,precise measurements of AME can also provide a newwindow into the ISM, complementing other multiwave-length tracers.A number of searches for extragalactic AME havebeen undertaken with WMAP and Planck data (e.g.,the Magellanic Clouds and NGC4945: Bot et al. 2010;Peel et al. 2011), all of which were inconclusive. Mostrecently, we have identified two additional detectionsof AME in the SFRS sample as having anomalouslyhigh 33 GHz-to-24 µ m flux ratios (NGC 6946 E4 andNGC 4725 B: Murphy et al. 2010, 2018b). NGC 4725 Bin particular appears consistent with a highly-embedded( A V > ∼ FRS: 3 - 33 GHz Imaging of Star-Forming Regions Figure 7.
Left panel: The evolution of the 3-33 GHz spectral slope in SB99 models of both an instantaneous burst and continuous SFH,using standard Kroupa IMF, and solar metallicities. We perform a χ -minimization of these models to the observed 3 −
33 GHz spectralindex of each region. Right panel: The distribution of model ages for both types of SFH (blue and green) and the best-fitting model ineach case (grey). It is clear that there exists two populations of regions: Those younger than t ∼
10 Myr, which are best-modeled by aninstantaneous burst, and those older than t ∼
10 Myr, which are best-modeled by a continuous SFH. their natal cocoons of gas and dust, lacking enoughsupernova to produce synchrotron emission.While it is possible that NGC 4725 B and NGC 6946 E4represent the most favorable conditions for AME detec-tion, there are likely remaining regions in the SFRSthat still harbor AME at a lower level relative to theother emission components (Hensley et al. 2015). Iso-lating the factors that govern the level of AME in theseregions will lend insight into the physical mechanismspowering this emission as well as the nature of its car-riers. In particular, we have observed that a commonfeature among both detections thus far is a shallow oreven rising spectra from 3 - 33 GHz, as the contributionfrom AME increases and eventually dominates beyond ∼
20 GHz. These regions can be identified as havingelevated 33 GHz emission relative to the expected ex-trapolation from lower-frequency radio data using astandard two-component power law.By measuring the 3 −
33 and 15 −
33 GHz spectralindices, we made an initial selection of 58 extragalac-tic AME candidates as regions that have an 8 µ m coun-terpart, a S/N ≥ r G > ≥ σ above the canonical α T = − . −
33 GHz. This assump-tion is well-supported here for our full spectral analysisof over 300 star-forming regions identified in the SFRS,which show that the median thermal fraction measuredat 33 GHz on a few ∼
100 pc scales is ∼ −
33 GHz spectrum of the 33AME candidate regions normalized to the highest mea-sured 3 GHz flux density. Viewed in this way we see thatmany of our AME candidates, similar to NGC 4725 B,have shallow or slightly negative slopes from 3 −
15 GHz,and a much steeper positive slope from 15 −
33 GHz.However, there are some regions which look more simi-lar to NGC 6946 Enuc 4., which have steeper 3 −
15 GHzslopes and a less significant increase from 15 −
33 GHz.Importantly, these spectra cannot be explained by a8
Linden et al.
Figure 8.
The radio spectra of all 33 AME candidates iden-tified in the SFRS as having 3 −
33 GHz or 15 −
33 GHz spec-tral indices 3 σ greater than α T = − .
1. To demonstrate thediversity of our AME candidate spectra we normalize all fluxdensity measurements to the brightest region detected at 3GHz. We expect that, similar to NGC 6946 E4 (Red), theregions with decreasing 3 −
15 GHz spectral slopes contain anon-negligible amount of synchrotron emission, whereas theregions with very shallow or even rising spectra over thissame frequency range (e.g. similiar to NGC 4725 B: Blue)will be dominated by free-free emission. simple combination of synchrotron (green) and free-free(yellow) emission components, suggesting that either anadditional emission component peaking at (cid:38)
15 GHz isrequired (e.g., AME), it is a (very) high-frequency GHz-peaked background galaxy, or the source is variable. Afinal possibility is that the free-free emission is optically-thick at 33 GHz. However, such ‘ultra-compact’ H ii regions have much higher radio luminosities and SFRs( ∼ −
60 mJy) then the regions identified here (e.g.,Meier et al. 2002). CONCLUSIONSWe have presented 3, 15, and 33 GHz imaging towardsgalaxy nuclei and extranuclear star-forming regions inthe SFRS, and have identified 335 regions (286 SF, 10BG, 6 SNe/R, and 33 AME) with
S/N ≥ ∼
100 pc scales is ∼ − −
40% found for the sampleof regions studied at 25 (cid:48)(cid:48) ( ∼ ∼
100 pc scales, the median thermal fraction at33 GHz of all regions identified as non-backgroundgalaxies is 92 ± .
8% with a median absolute devia-tion of 11%. Limiting our analysis to extranuclear( r G > ± .
8% with a median ab-solute deviation of 10%. Further, we find that on7 (cid:48)(cid:48) scales the median thermal fraction is 94 ± . ≥
90% upto ∼
500 pc scales.3. We have confirmed through MCMC analysis thatwe do not introduce systematic biases when inter-preting the results of the χ -minimization of a two-component power-law model to fit the observed ra-dio spectrum from 3 −
33 GHz, and that this modelcan adequately separate the thermal free-free andnonthermal synchrotron emission components overa realistic range of input values.4. We find a systematic increase in the scatter of themeasured spectral indices and thermal fractions asthe de-projected galactocentric radius approachesthe nucleus. This trend is reflective of the ongo-ing star-formation activity occurring in centers ofthese galaxies, and results in a larger contributionof diffuse nonthermal emission.5. We have identified a sample of 33 sources whoserising 15 −
33 GHz emission may be due to anoma-lous microwave emission. Follow-up observationsat high ( ≥
40 GHz) frequencies will be necessaryto confirm these sources as discrete regions of ex-tragalactic AME.S.T.L. was supported by the NRAO Grote Reber Dis-sertation Fellowship. The National Radio AstronomyObservatory is a facility of the National Science Foun-dation operated under cooperative agreement by Asso-ciated Universities, Inc. This research has made use ofthe NASA/IPAC Extragalactic Database (NED) whichis operated by the Jet Propulsion Laboratory, Califor-nia Institute of Technology, under contract with the Na-tional Aeronautics and Space Administration.
FRS: 3 - 33 GHz Imaging of Star-Forming Regions
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FRS: 3 - 33 GHz Imaging of Star-Forming Regions
Table 6 . Ancillary Source Photometry at 7 (cid:48)(cid:48)
Angular Resolution
Source ID f ν (1528 ˚A) f ν (2271 ˚A) f H α / − f ν (24 µ m)( µ Jy) ( µ Jy) (erg s − cm − ) (mJy)Star-Forming RegionsNGC 0337 a 76 . ± .
46 163 . ± .
54 1 . ± .
29 45 . ± . . ± .
71 185 . ± .
76 1 . ± .
37 81 . ± . . ± .
54 70 . ± .
58 0 . ± .
11 8 . ± . . ± .
08 87 . ± .
15 1 . ± .
24 22 . ± . . ± .
15 81 . ± .
19 0 . ± .
11 9 . ± . . ± .
58 95 . ± .
32 0 . ± .
08 40 . ± . . ± .
00 282 . ± .
34 0 . ± .
16 28 . ± . . ± .
54 41 . ± .
19 0 . ± .
01 2 . ± . . ± .
23 134 . ± .
22 0 . ± .
15 75 . ± . . ± .
01 226 . ± . · · · . ± . . ± .
39 232 . ± .
83 0 . ± .
07 2 . ± . . ± .
16 30 . ± . · · · . ± . . ± .
60 242 . ± . · · · . ± . . ± .
06 32 . ± . · · · . ± . . ± .
09 42 . ± . · · · . ± . . ± .
22 77 . ± . · · · . ± . . ± .
48 10 . ± . · · · . ± . · · · · · · · · · . ± . . ± .
56 31 . ± . · · · . ± . . ± .
12 402 . ± .
30 1 . ± .
24 9 . ± . . ± .
25 67 . ± .
15 0 . ± .
03 3 . ± . . ± .
86 2032 . ± .
81 2 . ± .
54 84 . ± . . ± .
82 101 . ± .
28 0 . ± .
14 34 . ± . . ± .
32 78 . ± .
84 0 . ± .
03 3 . ± . . ± .
02 1047 . ± .
12 2 . ± .
46 58 . ± . . ± .
47 218 . ± .
84 0 . ± .
16 17 . ± . . ± .
04 373 . ± .
05 1 . ± .
28 16 . ± . . ± .
87 412 . ± .
92 4 . ± .
95 1084 . ± . . ± .
84 213 . ± .
98 0 . ± .
05 12 . ± . . ± .
40 24 . ± .
68 0 . ± .
11 27 . ± . . ± .
45 216 . ± .
53 3 . ± .
66 129 . ± . . ± .
54 89 . ± .
45 0 . ± .
11 7 . ± . . ± .
60 154 . ± .
12 1 . ± .
38 53 . ± . . ± .
07 74 . ± .
23 1 . ± .
22 23 . ± . . ± .
73 736 . ± .
48 1 . ± .
30 180 . ± . · · · · · · . ± . · · · † NGC 3190 9 . ± .
49 57 . ± .
68 0 . ± .
03 30 . ± . . ± .
23 243 . ± .
48 0 . ± .
05 55 . ± . . ± .
47 29 . ± .
45 0 . ± .
02 176 . ± . . ± .
37 551 . ± .
71 1 . ± .
34 4 . ± . . ± .
24 141 . ± .
19 1 . ± .
34 19 . ± . . ± .
65 297 . ± . · · · . ± . . ± .
05 839 . ± .
85 2 . ± .
47 307 . ± . . ± .
23 655 . ± .
28 2 . ± .
43 389 . ± . Table 6 continued Linden et al.
Table 6 (continued)
Source ID f ν (1528 ˚A) f ν (2271 ˚A) f H α / − f ν (24 µ m)( µ Jy) ( µ Jy) (erg s − cm − ) (mJy)NGC 3521 Enuc. 1 14 . ± .
15 18 . ± .
78 0 . ± .
02 6 . ± . . ± .
36 15 . ± .
32 0 . ± .
02 6 . ± . . ± .
45 135 . ± .
30 0 . ± .
12 12 . ± . . ± .
86 27 . ± .
09 0 . ± .
05 18 . ± . . ± .
95 12 . ± .
87 0 . ± .
010 2 . ± . . ± .
34 48 . ± . · · · . ± . . ± .
42 100 . ± .
15 0 . ± .
19 246 . ± . . ± .
83 9 . ± .
37 0 . ± .
08 170 . ± . . ± .
21 47 . ± .
15 0 . ± .
19 478 . ± . . ± .
54 1035 . ± . · · · . ± . . ± .
76 102 . ± .
37 0 . ± .
01 5 . ± . . ± .
46 80 . ± .
04 0 . ± .
06 7 . ± . . ± .
15 109 . ± .
41 0 . ± .
07 21 . ± . . ± .
37 118 . ± .
79 0 . ± .
07 13 . ± . . ± .
95 122 . ± .
33 0 . ± .
04 11 . ± . . ± .
46 115 . ± .
37 0 . ± .
09 32 . ± . . ± .
30 53 . ± .
05 0 . ± .
05 22 . ± . . ± .
17 160 . ± .
12 0 . ± .
12 53 . ± . . ± .
01 208 . ± .
32 0 . ± .
11 18 . ± . . ± .
78 114 . ± .
21 0 . ± .
08 25 . ± . . ± .
17 145 . ± .
76 0 . ± .
10 31 . ± . . ± .
24 99 . ± .
88 0 . ± .
05 14 . ± . . ± .
16 134 . ± .
24 0 . ± .
07 25 . ± . . ± .
98 101 . ± .
26 0 . ± .
05 11 . ± . . ± .
63 101 . ± .
18 0 . ± .
03 7 . ± . . ± .
79 109 . ± .
44 0 . ± .
03 6 . ± . . ± .
85 35 . ± .
34 0 . ± .
01 4 . ± . . ± .
10 1001 . ± .
28 0 . ± .
17 88 . ± . . ± .
22 535 . ± .
36 0 . ± .
18 117 . ± . . ± .
11 84 . ± .
67 0 . ± .
02 4 . ± . . ± .
32 93 . ± .
04 1 . ± .
39 976 . ± . . ± .
87 167 . ± .
09 0 . ± .
15 9 . ± . . ± .
88 258 . ± .
75 0 . ± .
12 5 . ± . . ± .
18 126 . ± .
94 0 . ± .
13 18 . ± . . ± .
60 1095 . ± .
27 3 . ± .
65 312 . ± . . ± .
49 180 . ± .
14 1 . ± .
39 96 . ± . . ± .
58 238 . ± .
76 0 . ± .
16 34 . ± . . ± .
47 145 . ± .
77 0 . ± .
03 4 . ± . . ± .
56 105 . ± .
77 0 . ± .
08 40 . ± . . ± .
98 144 . ± .
60 0 . ± .
10 85 . ± . . ± .
63 183 . ± .
53 0 . ± .
05 167 . ± . . ± .
27 92 . ± .
83 0 . ± .
08 45 . ± . . ± .
58 68 . ± .
31 0 . ± .
06 268 . ± . . ± .
32 106 . ± .
98 0 . ± .
13 18 . ± . . ± .
56 345 . ± .
78 1 . ± .
34 41 . ± . . ± .
56 5 . ± .
00 0 . ± .
003 0 . ± . . ± .
75 926 . ± .
95 0 . ± .
11 302 . ± . . ± .
63 438 . ± .
81 0 . ± .
18 83 . ± . . ± .
32 265 . ± .
83 0 . ± .
16 88 . ± . . ± .
68 257 . ± .
61 0 . ± .
11 90 . ± . . ± .
31 227 . ± .
10 3 . ± .
73 198 . ± . . ± .
63 169 . ± .
38 1 . ± .
26 40 . ± . . ± .
96 116 . ± .
42 0 . ± .
14 22 . ± . Table 6 continued
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 6 (continued)
Source ID f ν (1528 ˚A) f ν (2271 ˚A) f H α / − f ν (24 µ m)( µ Jy) ( µ Jy) (erg s − cm − ) (mJy)NGC 5194 Enuc. 6 a 47 . ± .
09 57 . ± .
64 0 . ± .
10 25 . ± . . ± .
50 425 . ± .
80 1 . ± .
30 98 . ± . . ± .
14 548 . ± .
23 0 . ± .
14 60 . ± . . ± .
62 214 . ± .
10 0 . ± .
09 13 . ± . . ± .
17 44 . ± .
70 0 . ± .
03 9 . ± . . ± .
60 28 . ± .
34 0 . ± .
02 14 . ± . . ± .
60 17 . ± .
63 0 . ± .
02 2 . ± . . ± .
63 46 . ± .
05 0 . ± .
07 50 . ± . . ± .
66 240 . ± .
08 0 . ± .
13 36 . ± . . ± .
91 179 . ± .
93 1 . ± .
20 73 . ± . . ± .
28 341 . ± .
22 0 . ± .
14 30 . ± . . ± .
71 316 . ± .
54 1 . ± .
32 95 . ± . . ± .
33 31 . ± .
76 0 . ± .
04 19 . ± . . ± .
15 171 . ± .
71 0 . ± .
004 33 . ± . . ± .
16 75 . ± .
25 0 . ± .
004 12 . ± . . ± .
87 521 . ± .
16 0 . ± .
13 104 . ± . . ± .
61 70 . ± .
58 0 . ± .
07 38 . ± . . ± .
67 208 . ± .
30 0 . ± .
004 22 . ± . . ± .
65 386 . ± .
97 0 . ± .
004 32 . ± . . ± .
76 126 . ± .
96 0 . ± .
07 51 . ± . . ± .
50 93 . ± .
00 0 . ± .
08 9 . ± . . ± .
90 256 . ± .
51 0 . ± .
13 109 . ± . . ± .
38 217 . ± .
69 1 . ± .
22 50 . ± . . ± .
70 110 . ± .
53 0 . ± .
07 14 . ± . . ± .
74 454 . ± . · · · . ± . . ± .
19 854 . ± .
12 1 . ± .
34 61 . ± . . ± .
13 511 . ± .
78 1 . ± .
27 56 . ± . . ± .
03 312 . ± .
93 1 . ± .
24 63 . ± . . ± .
93 1143 . ± .
53 2 . ± .
51 74 . ± . . ± .
33 99 . ± .
93 0 . ± .
04 13 . ± . . ± .
90 537 . ± .
63 0 . ± .
09 52 . ± . . ± .
24 112 . ± .
82 0 . ± .
10 15 . ± . . ± .
60 238 . ± .
75 0 . ± .
20 51 . ± . . ± .
76 898 . ± .
83 4 . ± .
98 597 . ± . . ± .
52 43 . ± .
48 0 . ± .
06 38 . ± . . ± .
59 375 . ± .
36 0 . ± .
11 7 . ± . . ± .
52 441 . ± .
25 0 . ± .
12 11 . ± . . ± .
43 413 . ± .
95 1 . ± .
23 39 . ± . . ± .
28 432 . ± .
92 1 . ± .
23 26 . ± . . ± .
55 97 . ± .
70 0 . ± .
02 1 . ± . . ± .
58 254 . ± .
23 0 . ± .
08 57 . ± . . ± .
45 72 . ± .
81 0 . ± .
01 32 . ± . . ± .
70 208 . ± .
22 0 . ± .
01 54 . ± . . ± .
48 322 . ± .
34 0 . ± .
02 364 . ± . . ± .
93 48 . ± . · · · . ± . . ± .
99 9 . ± . · · · . ± . . ± .
97 11 . ± . · · · . ± . . ± .
04 9 . ± .
51 1 . ± .
27 78 . ± . . ± .
35 11 . ± .
69 0 . ± .
12 4 . ± . . ± .
20 9 . ± .
48 1 . ± .
23 5 . ± . . ± .
08 37 . ± .
58 1 . ± .
32 70 . ± . . ± .
12 13 . ± .
09 0 . ± .
19 43 . ± . . ± .
23 22 . ± .
41 2 . ± .
57 103 . ± . Table 6 continued Linden et al.
Table 6 (continued)
Source ID f ν (1528 ˚A) f ν (2271 ˚A) f H α / − f ν (24 µ m)( µ Jy) ( µ Jy) (erg s − cm − ) (mJy)NGC 6946 Enuc. 6 b 8 . ± .
36 9 . ± .
42 1 . ± .
20 42 . ± . . ± .
57 13 . ± .
02 1 . ± .
23 71 . ± . . ± .
18 173 . ± .
03 8 . ± .
64 67 . ± . . ± .
31 53 . ± . < . ± . . ± .
61 381 . ± .
18 0 . ± .
13 5 . ± . . ± .
79 357 . ± .
57 0 . ± .
14 25 . ± . . ± .
21 286 . ± .
98 0 . ± .
12 10 . ± . . ± .
01 462 . ± .
30 0 . ± .
14 15 . ± . . ± .
56 45 . ± .
88 0 . ± .
04 5 . ± . . ± .
68 31 . ± .
78 2 . ± .
44 10 . ± . . ± .
23 1026 . ± .
96 2 . ± .
46 52 . ± . . ± .
85 1561 . ± .
19 4 . ± .
97 284 . ± . . ± .
39 68 . ± .
26 0 . ± .
01 3 . ± . . ± .
86 392 . ± .
84 0 . ± .
16 7 . ± . . ± .
92 154 . ± .
24 0 . ± .
09 92 . ± . . ± .
11 114 . ± .
18 0 . ± .
08 74 . ± . . ± .
89 88 . ± .
25 0 . ± .
07 143 . ± . . ± .
89 82 . ± . < . ± . . ± .
57 34 . ± .
19 0 . ± .
11 81 . ± . . ± .
24 27 . ± .
13 0 . ± .
05 23 . ± . . ± .
02 95 . ± .
37 0 . ± .
14 32 . ± . . ± .
59 41 . ± .
29 0 . ± .
004 10 . ± . . ± .
68 314 . ± .
20 0 . ± .
14 24 . ± . < < . ± .
69 53 . ± . . ± .
02 47 . ± . · · · . ± . . ± .
32 51 . ± .
70 2 . ± .
45 21 . ± . . ± .
83 11 . ± .
71 4 . ± .
92 2075 . ± . . ± .
59 36 . ± .
53 3 . ± .
69 115 . ± . . ± .
41 38 . ± .
76 2 . ± .
57 46 . ± . . ± .
80 41 . ± .
19 2 . ± .
47 17 . ± . Note — † Photometry unreliable and not reported due to saturation by the nucleus in the 24 µ m image. Table 7 . Local Background Measurements
Source ID Back
Back
15 GHz
Back
33 GHz f Back f
15 GHz
Back f
33 GHz
Back (mJy) (mJy) (mJy) ( ‡ ) ( ‡ ) ( ‡ )Star-Forming RegionsNGC 0337 D 0.207 0.099 0.019 0.174 0.130 0.062NGC 0337 A 0.046 0.070 0.024 0.046 0.100 0.085NGC 0337 B 0.133 0.059 -0.022 0.027 0.022 0.012 Table 7 continued
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 7 (continued)
Source ID Back
Back
15 GHz
Back
33 GHz f Back f
15 GHz
Back f
33 GHz
Back (mJy) (mJy) (mJy) ( ‡ ) ( ‡ ) ( ‡ )NGC 0337 C 0.026 0.019 0.005 0.087 0.064 0.024NGC 0337 G 0.030 0.013 -0.005 0.082 0.068 0.032NGC 0337 E 0.026 0.027 0.010 0.096 0.099 0.034NGC 0337 F 0.021 0.038 0.023 0.075 0.195 0.104NGC 0628 Enuc. 4 -0.004 0.013 0.013 0.015 0.049 0.057NGC 0628 Enuc. 2 0.017 -0.012 0.026 0.033 0.033 0.092NGC 0628 Enuc. 3 C 0.009 0.010 0.018 0.033 0.050 0.080NGC 0628 Enuc. 3 A † -0.007 0.019 -0.012 0.013 0.052 0.024NGC 0628 Enuc. 3 B 0.023 0.018 0.014 0.080 0.091 0.066NGC 0628 Enuc. 1 B · · · · · · · · · · · · NGC 0628 Enuc. 1 A 0.007 0.029 -0.031 0.026 0.114 0.118NGC 0855 C 0.082 0.071 0.018 0.045 0.067 0.024NGC 0855 A † · · · · · · NGC 0925 A 0.020 · · · · · · · · · · · ·
NGC 0925 B -0.001 -0.003 · · · · · ·
NGC 1097 Enuc. 2 0.005 · · · · · · † · · · · · · · · · · · · † † · · · · · · NGC 1482 C 1.810 0.339 0.237 0.039 0.026 0.026NGC 1482 A † † · · · · · · NGC 2403 Enuc. 5 B 0.004 0.006 0.006 0.026 0.033 0.059NGC 2403 Enuc. 6 A -0.023 0.026 0.008 0.026 0.030 0.011NGC 2403 Enuc. 6 B 0.015 · · · · · · · · · · · ·
NGC 2403 Enuc. 1 A -0.001 0.013 -0.001 0.001 0.033 0.003NGC 2403 C 0.002 0.012 · · · · · ·
NGC 2403 Enuc. 1 B 0.031 0.066 0.040 0.020 0.048 0.035NGC 2403 Enuc. 1 C 0.036 0.005 0.003 0.076 0.048 0.035NGC 2403 Enuc. 1 D 0.022 0.023 0.009 0.108 0.170 0.079NGC 2403 Enuc. 2 B -0.008 0.018 -0.002 0.020 0.055 0.009
Table 7 continued Linden et al.
Table 7 (continued)
Source ID Back
Back
15 GHz
Back
33 GHz f Back f
15 GHz
Back f
33 GHz
Back (mJy) (mJy) (mJy) ( ‡ ) ( ‡ ) ( ‡ )NGC 2403 Enuc. 2 D 0.039 0.030 0.029 0.061 0.054 0.053NGC 2403 Enuc. 2 A † · · · · · · · · · · · · NGC 2403 E 0.013 · · · · · · · · · · · ·
NGC 2403 Enuc. 3 B 0.177 0.165 0.229 0.046 0.052 0.079NGC 2403 Enuc. 4 B · · · · · · · · · · · · · · · · · · · · · · · ·
NGC 2976 Enuc. 1 A 0.043 0.044 0.032 0.038 0.057 0.043NGC 2976 Enuc. 1 D 0.143 0.101 0.073 0.064 0.056 0.047NGC 2976 Enuc. 1 C 0.019 0.019 0.019 0.039 0.052 0.059NGC 2976 Enuc. 1 B † · · · -0.004 · · · · · · · · · NGC 2976 Enuc. 2 A 0.069 0.068 0.025 0.041 0.046 0.020NGC 2976 Enuc. 2 C 0.047 0.045 0.015 0.084 0.099 0.038NGC 2976 C 0.012 · · · · · · · · · · · ·
NGC 3049 A 0.007 0.021 0.018 0.005 0.039 0.040NGC 3049 B 0.005 0.014 0.014 0.015 0.066 0.090NGC 3049 C 0.009 · · · · · · · · · · · ·
NGC 3077 A 0.523 0.387 0.170 0.046 0.054 0.027NGC 3190 A 0.024 0.008 0.005 0.043 0.013 0.004NGC 3184 B 0.013 0.012 · · · · · ·
NGC 3184 A 0.027 -0.006 -0.004 0.042 0.018 0.012NGC 3198 B 0.014 0.001 · · · · · ·
NGC 3198 A 0.020 0.013 -0.023 0.041 0.044 0.120NGC 3198 C -0.019 0.015 · · · · · ·
IC 2574 D 0.032 0.016 0.010 0.033 0.053 0.021IC 2574 C 0.160 0.112 0.060 0.179 0.178 0.077IC 2574 A 0.009 0.004 0.011 0.016 0.008 0.023IC 2574 B -0.005 0.005 · · · · · ·
NGC 3265 A 0.145 0.044 0.028 0.053 0.066 0.066NGC 3351 C -0.016 -0.022 -0.010 0.007 0.021 0.008NGC 3351 A 0.497 0.179 0.036 0.069 0.065 0.018NGC 3351 B 0.409 0.101 0.109 0.046 0.028 0.048NGC 3521 Enuc. 1 -0.022 0.023 · · · · · ·
NGC 3521 Enuc. 3 A · · · · · · · · · · · ·
NGC 3521 Enuc. 2 A 0.021 0.016 -0.019 0.032 0.047 0.068NGC 3521 Enuc. 3 C 0.021 · · · · · · · · · · · ·
NGC 3521 Enuc. 2 B 0.011 0.012 · · · · · ·
NGC 3621 C 0.025 0.032 · · · · · ·
NGC 3621 A 0.060 0.026 · · · · · ·
NGC 3621 H 0.012 · · · · · · · · · · · ·
NGC 3621 G † · · · · · · NGC 3621 B 0.035 0.048 · · · · · ·
NGC 3621 F 0.002 · · · · · · · · · · · ·
NGC 3621 E -0.001 -0.010 · · · · · ·
Table 7 continued
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 7 (continued)
Source ID Back
Back
15 GHz
Back
33 GHz f Back f
15 GHz
Back f
33 GHz
Back (mJy) (mJy) (mJy) ( ‡ ) ( ‡ ) ( ‡ )NGC 3627 Enuc. 1 G 0.037 · · · · · · · · · · · · NGC 3627 Enuc. 1 F 0.015 · · · · · · · · · · · ·
NGC 3627 Enuc. 1 E -0.002 · · · · · · † · · · · · · NGC 3773 0.078 0.049 0.017 0.031 0.036 0.015NGC 3938 B 0.028 · · · · · · · · · · · ·
NGC 3938 Enuc. 2 B 0.002 -0.003 0.011 0.009 0.027 0.060NGC 3938 Enuc. 2 A -0.007 0.000 -0.003 0.021 0.000 0.013NGC 4254 Enuc. 2 D · · · · · · · · · · · · · · · · · · · · · · · ·
NGC 4254 Enuc. 2 E -0.003 · · · · · · · · · · · ·
NGC 4254 0.024 0.095 0.014 0.059 0.185 0.038NGC 4254 Enuc. 1 D 0.056 0.011 0.014 0.071 0.046 0.040NGC 4254 Enuc. 1 B 0.033 -0.004 0.023 0.152 0.028 0.056NGC 4254 Enuc. 1 C 0.002 · · · -0.008 0.008 · · · · · · -0.010 0.082 · · · † · · · · · · NGC 4536 C 2.914 0.834 0.455 0.086 0.066 0.057NGC 4536 A † · · · · · · NGC 4559 C -0.013 0.028 0.005 0.065 0.158 0.026NGC 4559 D · · · · · · · · · · · ·
NGC 4559 B 0.012 0.010 0.002 0.130 0.064 0.018NGC 4559 A 0.002 0.008 0.002 0.014 0.073 0.013NGC 4569 A 0.253 0.180 0.057 0.088 0.125 0.065NGC 4579 -0.139 0.254 0.152 0.068 0.092 0.255NGC 4594 -0.021 0.011 0.021 0.025 0.023 0.026NGC 4631 Enuc. 1 -0.000 0.064 0.049 0.000 0.097 0.080NGC 4625 A · · · · · · · · · · · ·
NGC 4631 A 0.044 0.178 0.034 0.006 0.072 0.023NGC 4631 H 0.128 0.195 0.071 0.130 0.149 0.084NGC 4631 B 0.456 0.220 0.208 0.083 0.066 0.068NGC 4631 G 0.043 0.050 0.030 0.047 0.068 0.049NGC 4631 Enuc. 2 B 0.014 0.042 -0.000 0.009 0.030 0.000NGC 4631 Enuc. 2 C · · · · · · · · · · · ·
NGC 4725 C -0.007 0.000 · · · · · ·
Table 7 continued Linden et al.
Table 7 (continued)
Source ID Back
Back
15 GHz
Back
33 GHz f Back f
15 GHz
Back f
33 GHz
Back (mJy) (mJy) (mJy) ( ‡ ) ( ‡ ) ( ‡ )NGC 4725 A 0.003 0.002 0.001 0.038 0.014 0.002NGC 4736 K 0.004 0.015 · · · · · · NGC 4736 J 0.104 0.001 · · · · · ·
NGC 4736 I 0.097 0.034 · · · · · ·
NGC 4736 G 0.044 · · · · · · · · · · · ·
NGC 4736 L 0.047 · · · · · · · · · · · ·
NGC 4736 H 0.088 0.080 0.026 0.069 0.074 0.074NGC 4736 M -0.016 · · · · · · · · · · · ·
NGC 4736 F 0.134 0.108 · · · · · ·
NGC 4736 N -0.004 0.133 · · · · · ·
NGC 4736 A 0.193 -0.016 0.021 0.031 0.007 0.017NGC 4736 O 0.015 0.086 0.024 0.084 0.194 0.062NGC 4736 E · · · · · · · · · · · ·
NGC 4736 P 0.133 0.036 -0.008 0.126 0.120 0.013NGC 4736 D 0.015 0.112 0.009 0.025 0.107 0.020NGC 4736 Enuc. 1 D 0.015 0.015 0.030 0.096 0.044 0.109NGC 4736 Enuc. 1 A 0.049 0.099 0.093 0.032 0.093 0.106NGC 4736 Enuc. 1 B 0.148 0.038 0.065 0.053 0.024 0.063NGC 4736 Enuc. 1 C -0.002 0.062 0.027 0.001 0.054 0.043NGC 4736 Enuc. 1 E 0.013 · · · · · · † · · · · · · · · · · · · NGC 5055 D 0.023 0.040 · · · · · ·
NGC 5055 A 0.204 0.150 0.066 0.103 0.149 0.197NGC 5055 B -0.011 0.002 · · · · · ·
NGC 5055 Enuc. 1 0.002 0.024 0.020 0.005 0.055 0.050NGC 5194 Enuc. 6 0.034 0.043 0.044 0.050 0.082 0.078NGC 5194 Enuc. 3 B · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
NGC 5194 I 0.474 0.124 0.039 0.088 0.087 0.055NGC 5194 C † Table 7 continued
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 7 (continued)
Source ID Back
Back
15 GHz
Back
33 GHz f Back f
15 GHz
Back f
33 GHz
Back (mJy) (mJy) (mJy) ( ‡ ) ( ‡ ) ( ‡ )NGC 5194 Enuc. 1 A 0.025 0.001 0.007 0.076 0.010 0.027NGC 5194 Enuc. 4 D · · · · · · · · · · · · · · · · · · NGC 5194 F 0.024 0.041 0.014 0.032 0.079 0.044NGC 5194 Enuc. 4 C 0.021 0.004 0.004 0.129 0.036 0.033NGC 5194 P 0.112 0.014 0.002 0.157 0.048 0.010NGC 5194 Enuc. 4 E · · · · · · · · · · · · · · · -0.002 0.046 · · · · · · · · ·
NGC 5194 Enuc. 8 B 0.052 0.048 0.005 0.078 0.075 0.024NGC 5194 Enuc. 7 E · · · · · · · · · · · ·
NGC 5194 Enuc. 7 F 0.011 0.052 · · · · · ·
NGC 5194 Enuc. 8 D 0.002 -0.018 · · · · · ·
NGC 5398 0.000 0.024 0.002 0.000 0.014 0.001NGC 5457 Enuc. 6 A 0.092 0.099 0.018 0.088 0.106 0.033NGC 5457 Enuc. 6 E 0.071 0.077 0.024 0.106 0.174 0.052NGC 5457 Enuc. 6 B 0.183 0.118 0.060 0.078 0.075 0.079NGC 5457 Enuc. 6 C 0.060 0.066 0.013 0.060 0.090 0.023NGC 5457 Enuc. 6 D 0.023 0.031 0.005 0.040 0.084 0.016NGC 5457 Enuc. 6 F 0.009 0.009 · · · · · ·
NGC 5457 Enuc. 2 B 0.001 -0.001 · · · · · ·
NGC 5457 Enuc. 2 C -0.007 0.004 · · · · · ·
NGC 5457 Enuc. 5 B 0.099 0.118 0.033 0.067 0.099 0.029NGC 5457 Enuc. 5 A † · · · · · · · · · · · · NGC 5457 Enuc. 3 D 0.013 0.032 · · · · · ·
NGC 5457 Enuc. 3 A 0.029 0.065 0.043 0.032 0.075 0.065NGC 5457 Enuc. 3 B 0.257 0.299 0.087 0.022 0.032 0.012NGC 5457 Enuc. 3 C 0.030 0.018 -0.001 0.031 0.033 0.003NGC 5457 Enuc. 4 A 0.043 0.026 -0.001 0.104 0.101 0.006NGC 5457 Enuc. 4 B 0.049 0.045 0.010 0.145 0.160 0.038NGC 5457 Enuc. 4 C 0.081 0.078 0.041 0.098 0.140 0.090NGC 5457 Enuc. 4 D 0.081 0.047 0.026 0.080 0.081 0.073NGC 5457 Enuc. 7 D † Table 7 continued Linden et al.
Table 7 (continued)
Source ID Back
Back
15 GHz
Back
33 GHz f Back f
15 GHz
Back f
33 GHz
Back (mJy) (mJy) (mJy) ( ‡ ) ( ‡ ) ( ‡ )NGC 5713 C 0.420 0.186 0.103 0.078 0.093 0.069NGC 5713 G † · · · · · · · · · · · · NGC 5713 E 0.209 0.142 0.016 0.151 0.165 0.028NGC 5866 0.088 0.105 0.035 0.013 0.021 0.016NGC 6946 Enuc. 4 A 0.047 0.035 0.045 0.122 0.103 0.116NGC 6946 Enuc. 4 B 0.004 0.011 0.023 0.020 0.052 0.112NGC 6946 Enuc. 4 H -0.002 -0.003 0.000 0.023 0.028 0.002NGC 6946 Enuc. 8 A 0.223 0.041 0.042 0.099 0.056 0.051NGC 6946 Enuc. 5 A · · · · · · · · · · · · · · · · · · · · · · · ·
NGC 6946 Enuc. 5 B 0.009 0.027 0.010 0.028 0.071 0.026NGC 6946 Enuc. 3 A -0.014 0.014 0.010 0.135 0.069 0.043NGC 6946 Enuc. 3 B -0.011 0.029 0.014 0.089 0.143 0.069NGC 6946 A 0.751 0.529 0.154 0.036 0.062 0.035NGC 6946 Enuc. 3 C 0.015 0.049 0.028 0.031 0.103 0.065NGC 6946 B 0.007 0.027 -0.007 0.015 0.069 0.025NGC 6946 C 0.101 0.060 0.034 0.136 0.096 0.107NGC 6946 Enuc. 6 J 0.017 0.000 0.014 0.148 0.005 0.138NGC 6946 Enuc. 6 I 0.025 0.008 0.022 0.113 0.073 0.210NGC 6946 Enuc. 6 H 0.019 0.004 0.014 0.101 0.034 0.089NGC 6946 Enuc. 6 F 0.013 0.012 0.015 0.056 0.188 0.127NGC 6946 Enuc. 6 E · · · · · · · · · · · ·
NGC 6946 Enuc. 9 E -0.004 0.006 · · · · · ·
NGC 6946 Enuc. 9 D 0.031 0.023 · · · · · ·
NGC 6946 Enuc. 9 A 0.060 0.090 0.033 0.070 0.122 0.053NGC 6946 Enuc. 6 L 0.051 0.006 0.010 0.072 0.026 0.026NGC 6946 Enuc. 9 C -0.007 0.020 0.011 0.057 0.100 0.102NGC 6946 Enuc. 9 B 0.009 0.024 0.015 0.057 0.143 0.117NGC 6946 Enuc. 7 A -0.007 0.045 0.013 0.035 0.060 0.027NGC 6946 Enuc. 7 B -0.008 0.017 0.009 0.059 0.079 0.057NGC 6946 Enuc. 1 A -0.003 0.029 0.031 0.004 0.045 0.047NGC 6946 Enuc. 2 C 0.003 0.004 · · · · · ·
NGC 7331 G 0.120 · · · · · · · · · · · ·
NGC 7331 F 0.073 0.115 · · · · · ·
NGC 7331 H 0.069 -0.029 · · · · · ·
NGC 7331 I 0.076 0.143 · · · · · ·
NGC 7331 A -0.020 0.045 · · · · · ·
NGC 7331 E 0.061 · · · -0.057 0.067 · · · · · · · · ·
NGC 7331 D 0.014 0.076 · · · · · ·
NGC 7793 Enuc. 1 E -0.001 -0.004 · · · · · ·
NGC 7793 Enuc. 3 -0.006 0.002 · · · · · ·
NGC 7793 Enuc. 1 A 0.006 0.004 · · · · · ·
NGC 7793 C -0.004 0.004 -0.001 0.020 0.025 0.007NGC 7793 A -0.008 0.013 -0.003 0.035 0.067 0.016NGC 7793 Enuc. 1 B · · · · · · · · · · · ·
NGC 7793 Enuc. 1 C -0.005 0.001 · · · · · ·
NGC 7793 Enuc. 2 · · · · · · -0.006 · · · · · ·
Table 7 continued
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Table 7 (continued)
Source ID Back
Back
15 GHz
Back
33 GHz f Back f
15 GHz
Back f
33 GHz
Back (mJy) (mJy) (mJy) ( ‡ ) ( ‡ ) ( ‡ )Likely Background GalaxiesNGC 0925 C -0.001 -0.004 0.003 0.001 0.006 0.011IC 342 E 0.113 0.039 · · · · · · Holmberg II C 0.006 0.011 0.019 0.041 0.080 0.115NGC 2841 B -0.003 · · · · · · · · · · · ·
NGC 2976 Enuc. 1 E -0.005 · · · · · · · · · · · ·
NGC 3077 B -0.004 0.009 · · · · · ·
NGC 3190 B 0.089 0.027 0.017 0.042 0.040 0.034NGC 3265 B 0.001 -0.001 · · · · · ·
NGC 3351 D -0.011 0.014 · · · · · ·
NGC 3627 Enuc. 1 B -0.000 · · · · · · · · · · · ·
NGC 4569 B -0.017 · · · · · · · · · · · ·
NGC 4625 B 0.001 0.004 0.001 0.001 0.016 0.004NGC 6946 Enuc. 4 F 0.145 0.105 0.032 0.025 0.061 0.035NGC 6946 Enuc. 4 G -0.044 -0.002 0.011 0.018 0.002 0.022Likely Associated with SupernovaeNGC 2403 Enuc. 3 D · · · -0.038 · · · · · · · · ·
NGC 4736 B -0.016 · · · · · · · · · · · ·
NGC 4736 C -0.027 · · · · · · · · · · · ·
NGC 5194 D 0.034 0.065 0.045 0.028 0.103 0.055NGC 5194 Enuc. 7 D 0.028 -0.003 · · · · · ·
NGC 6946 F 0.016 0.012 · · · · · ·
NGC 6946 Enuc. 6 D 0.004 0.013 -0.003 0.013 0.036 0.015NGC 6946 Enuc. 2 B 0.006 0.087 0.029 0.005 0.061 0.015NGC 7331 C 0.040 0.379 0.055 0.051 0.205 0.076NGC 7793 B -0.002 · · · · · · · · · · · ·
Likely AME CandidatesNGC 2403 Enuc. 5 D 0.045 0.073 0.036 0.071 0.115 0.059NGC 2403 Enuc. 2 E 0.038 0.057 0.022 0.032 0.059 0.018NGC 2403 Enuc. 3 A 0.015 0.030 0.033 0.038 0.075 0.063NGC 2403 Enuc. 3 C 0.112 0.070 0.093 0.045 0.037 0.049NGC 3627 Enuc. 1 D 0.014 0.048 0.014 0.036 0.086 0.023NGC 3627 Enuc. 1 C 0.005 0.085 -0.004 0.011 0.134 0.004NGC 4254 Enuc. 2 A 0.005 0.008 0.011 0.041 0.052 0.049NGC 4254 Enuc. 1 A 0.013 0.007 0.020 0.037 0.053 0.088NGC 4631 C 0.115 0.020 0.081 0.066 0.023 0.065NGC 4631 D 0.065 0.013 0.078 0.042 0.025 0.083NGC 4631 E 0.075 0.038 0.065 0.080 0.083 0.083NGC 4631 F 0.418 0.259 0.212 0.061 0.079 0.053NGC 4631 Enuc. 2 A 0.033 0.006 0.005 0.055 0.027 0.013NGC 4725 B -0.003 0.001 0.003 0.024 0.005 0.008NGC 5194 Enuc. 2 0.019 0.011 0.018 0.015 0.024 0.032NGC 5194 Enuc. 1 C 0.053 0.030 0.033 0.098 0.064 0.045NGC 5194 Enuc. 1 B 0.034 0.025 0.023 0.069 0.051 0.043NGC 5194 Enuc. 4 A 0.040 -0.004 0.018 0.056 0.012 0.044NGC 5457 Enuc. 2 A 0.020 0.007 0.006 0.050 0.026 0.017NGC 5457 Enuc. 7 A 0.084 0.071 0.048 0.079 0.127 0.068NGC 5457 Enuc. 7 C 0.263 0.243 0.162 0.074 0.135 0.084
Table 7 continued Linden et al.
Table 7 (continued)
Source ID Back
Back
15 GHz
Back
33 GHz f Back f
15 GHz
Back f
33 GHz
Back (mJy) (mJy) (mJy) ( ‡ ) ( ‡ ) ( ‡ )NGC 6946 Enuc. 4 C 0.026 0.037 0.042 0.017 0.026 0.027NGC 6946 Enuc. 4 D -0.001 0.013 0.004 0.011 0.016 0.005NGC 6946 Enuc. 4 E 0.014 0.035 0.023 0.011 0.026 0.018NGC 6946 E 0.060 0.062 0.055 0.083 0.086 0.043NGC 6946 D 0.018 0.064 0.005 0.045 0.126 0.010NGC 6946 Enuc. 6 M -0.005 -0.012 0.006 0.009 0.133 0.014NGC 6946 Enuc. 6 G 0.050 0.019 0.044 0.064 0.038 0.080NGC 6946 Enuc. 6 K 0.063 0.025 0.051 0.090 0.064 0.112NGC 6946 Enuc. 6 A † · · · · · · Note — † The aperture used for this star-forming region contained multiple smaller individual regions.
Note — ‡ The fractional contribution of the absolute value of the local background measurement to theaperture flux density.
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Figure 9.
See description in Figure 1. Linden et al.
Figure 10.
See description in Figure 1.
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Figure 11.
See description in Figure 1. Linden et al.
Figure 12.
See description in Figure 1.
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Figure 13.
See description in Figure 1. Linden et al.
Figure 14.
See description in Figure 1.
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Figure 15.
See description in Figure 1. Linden et al.
Figure 16.
See description in Figure 1.
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Figure 17.
See description in Figure 1. Linden et al.
Figure 18.
See description in Figure 1.
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Figure 19.
See description in Figure 1. Linden et al.
Figure 20.
See description in Figure 1.
FRS: 3 - 33 GHz Imaging of Star-Forming Regions Figure 21.
See description in Figure 1. Linden et al.
Figure 22.
See description in Figure 1.