Tony Mroczkowski

SUNYAEV-ZEL'DOVICH-MEASURED PRESSURE PROFILES FROM THE BOLOCAM X-RAY/SZ GALAXY CLUSTER SAMPLE

We describe Sunyaev-Zel’dovich (SZ) effect measurements and analysis of the intracluster medium (ICM) pressure profiles of a set of 45 massive galaxy clusters imaged using Bolocam at the Caltech Submillimeter Observatory. We deproject the average pressure profile of our sample into 13 logarithmically spaced radial bins between 0.07R500 and 3.5R500, and we find that a generalized Navarro, Frenk, and White (gNFW) profile describes our data with sufficient goodness-of-fit and best-fit parameters (C500, �, �, , P0 = 1.18, 0.86, 3.67, 0.67, 4.29). We use X-ray data to define cool-core and disturbed subsamples of clusters, and we constrain the average pressure profiles of each of these subsamples. We find that, given the precision of our data, the average pressure profiles of disturbed and cool-core clusters are consistent with one another at R & 0.15R500, with cool-core systems showing indications of higher pressure at R . 0.15R500. In addition, for the first time, we place simultaneous constraints on the mass scaling of cluster pressure profiles, their ensemble mean profile, and their radius-dependent intrinsic scatter between 0.1R500 and 2.0R500. The scatter among profiles is minimized at radii between ≃ 0.2R500 and ≃ 0.5R500, with a value of ≃ 20%. These results for the intrinsic scatter are largely consistent with previous analyses, most of which have relied heavily on X-ray derived pressures of clusters at significantly lower masses and redshifts compared to our sample. Therefore, our data provide further evidence that cluster pressure profiles are largely universal with scatter of ≃ 20–40% about the universal profile over a wide range of masses and redshifts. Subject headings: galaxies: clusters: general — galaxies: clusters: intracluster medium

Application of a Self-Similar Pressure Profile to Sunyaev-Zel'Dovich Effect Data from Galaxy Clusters

We investigate the utility of a new, self-similar pressure profile for fitting Sunyaev–Zel’dovich (SZ) effect observations of galaxy clusters. Current SZ imaging instruments–such as the Sunyaev–Zel’dovich Array (SZA)– are capable of probing clusters over a large range in a physical scale. A model is therefore required that can accurately describe a cluster’s pressure profile over a broad range of radii from the core of the cluster out to a significant fraction of the virial radius. In the analysis presented here, we fit a radial pressure profile derived from simulations and detailed X-ray analysis of relaxed clusters to SZA observations of three clusters with exceptionally high-quality X-ray data: A1835, A1914, and CL J1226.9+3332. From the joint analysis of the SZ and X-ray data, we derive physical properties such as gas mass, total mass, gas fraction and the intrinsic, integrated Compton y-parameter. We find that parameters derived from the joint fit to the SZ and X-ray data agree well with a detailed, independent X-ray-only analysis of the same clusters. In particular, we find that, when combined with X-ray imaging data, this new pressure profile yields an independent electron radial temperature profile that is in good agreement with spectroscopic X-ray measurements.

THREE-DIMENSIONAL MULTI-PROBE ANALYSIS OF THE GALAXY CLUSTER A1689*

The work is partially supported by the Ministry of Science and Technology of Taiwan under the grant MOST 103-2112-M-001-030-MY3. M. S. acknowledges financial contributions from contracts ASI/INAF I/023/ 12/0, by the PRIN MIUR 2010–2011 “The dark universe and the cosmic evolution of baryons: from current surveys to Euclid” and by the PRIN INAF 2012 “The universe in the box: multiscale simulations of cosmic structure.” M. N. acknowledges financial support from PRIN INAF 2014. J. M. D. acknowledges support of the consolider project CSD2010-00064 and AYA2012-39475-C02-01 funded by the Ministerio de Economia y Competitividad. N. O. is supported by a Grant-in-Aid from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (26800097). This work was partially supported by “World Premier International Research Center Initiative (WPI Initiative)” and the Funds for the Development of Human Resources in Science and Technology under MEXT, Japan. This research was performed while T. M. held a National Research Council Research Associateship Award at the Naval Research Laboratory (NRL). We thank John Carlstrom, Megan Gralla, Marshall Joy, Dan Marrone, and the entire SZA and OVRO/BIMA teams for providing the SZA and OVRO/BIMA data used in this study. Support for the SZA observations presented in this work was provided by NSF through award AST-0838187 and PHY-0114422 at the University of Chicago. The OVRO and BIMA observations presented here were supported by National Science Foundation grants AST 99-81546 and 02-28963.

FRONTIER FIELDS CLUSTERS: CHANDRA AND JVLA VIEW OF THE PRE-MERGING CLUSTER MACS J0416.1-2403

Merging galaxy clusters leave long-lasting signatures on the baryonic and non-baryonic cluster constituents, including shock fronts, cold fronts, X-ray substructure, radio halos, and offsets between the dark matter (DM) and the gas components. Using observations from Chandra, the Jansky Very Large Array, the Giant Metrewave Radio Telescope, and the Hubble Space Telescope, we present a multiwavelength analysis of the merging Frontier Fields cluster MACS J0416.1-2403 (z = 0.396), which consists of NE and SW subclusters whose cores are separated on the sky by ~250 kpc. We find that the NE subcluster has a compact core and hosts an X-ray cavity, yet it is not a cool core. Approximately 450 kpc south–southwest of the SW subcluster, we detect a density discontinuity that corresponds to a compression factor of ~1.5. The discontinuity was most likely caused by the interaction of the SW subcluster with a less massive structure detected in the lensing maps SW of the subclusters center. For both the NE and the SW subclusters, the DM and the gas components are well-aligned, suggesting that MACS J0416.1-2403 is a pre-merging system. The cluster also hosts a radio halo, which is unusual for a pre-merging system. The halo has a 1.4 GHz power of (1.3 ± 0.3) × 10^(24) W Hz^(−1), which is somewhat lower than expected based on the X-ray luminosity of the cluster if the spectrum of the halo is not ultra-steep. We suggest that we are either witnessing the birth of a radio halo, or have discovered a rare ultra-steep spectrum halo.

Lupus I Observations from the 2010 Flight of the Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry

The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) was created by adding polarimetric capability to the BLAST experiment that was flown in 2003, 2005, and 2006. BLASTPol inherited BLASTs 1.8 m primary and its Herschel/SPIRE heritage focal plane that allows simultaneous observation at 250, 350, and 500 μm. We flew BLASTPol in 2010 and again in 2012. Both were long duration Antarctic flights. Here we present polarimetry of the nearby filamentary dark cloud Lupus I obtained during the 2010 flight. Despite limitations imposed by the effects of a damaged optical component, we were able to clearly detect submillimeter polarization on degree scales. We compare the resulting BLASTPol magnetic field map with a similar map made via optical polarimetry. (The optical data were published in 1998 by J. Rizzo and collaborators.) The two maps partially overlap and are reasonably consistent with one another. We compare these magnetic field maps to the orientations of filaments in Lupus I, and we find that the dominant filament in the cloud is approximately perpendicular to the large-scale field, while secondary filaments appear to run parallel to the magnetic fields in their vicinities. This is similar to what is observed in Serpens South via near-IR polarimetry, and consistent with what is seen in MHD simulations by F. Nakamura and Z. Li.

Horn-coupled, commercially-fabricated aluminum lumped-element kinetic inductance detectors for millimeter wavelengths

We discuss the design, fabrication, and testing of prototype horn-coupled, lumped-element kinetic inductance detectors (LEKIDs) designed for cosmic microwave background studies. The LEKIDs are made from a thin aluminum film deposited on a silicon wafer and patterned using standard photolithographic techniques at STAR Cryoelectronics, a commercial device foundry. We fabricated 20-element arrays, optimized for a spectral band centered on 150 GHz, to test the sensitivity and yield of the devices as well as the multiplexing scheme. We characterized the detectors in two configurations. First, the detectors were tested in a dark environment with the horn apertures covered, and second, the horn apertures were pointed towards a beam-filling cryogenic blackbody load. These tests show that the multiplexing scheme is robust and scalable, the yield across multiple LEKID arrays is 91%, and the measured noise-equivalent temperatures for a 4 K optical load are in the range 26±6 μK√s.

J1649+2635: A Grand-Design Spiral with a Large Double-Lobed Radio Source

We report the discovery of a grand-design spiral galaxy associated with a double-lobed radio source. J1649+2635 (z = 0.0545) is a red spiral galaxy with a prominent bulge that it is associated with a L(1.4GHz) is approximately 10(exp24) W Hz(exp1) double-lobed radio source that spans almost 100 kpc. J1649+2635 has a black hole mass of M(BH) is approximately 3-7 10(exp8) Solar mass and SFR is approximately 0.26 - 2.6 solar mass year(exp1). The galaxy hosts a approximately 96 kpc diffuse optical halo, which is unprecedented for spiral galaxies. We find that J1649+2635 resides in an overdense environment with a mass of M(dyn) = 7.7(+7.9/4.3) 10(exp13) Solar mass, likely a galaxy group below the detection threshold of the ROSAT All-Sky Survey. We suggest one possible scenario for the association of double-lobed radio emission from J1649+2635 is that the source may be similar to a Seyfert galaxy, located in a denser-than-normal environment. The study of spiral galaxies that host large-scale radio emission is important because although rare in the local Universe, these sources may be more common at high-redshifts.

MAKO: a pathfinder instrument for on-sky demonstration of low-cost 350 micron imaging arrays

Submillimeter cameras now have up to 104 pixels (SCUBA 2). The proposed CCAT 25-meter submillimeter telescope will feature a 1 degree field-of-view. Populating the focal plane at 350 microns would require more than 106 photon-noise limited pixels. To ultimately achieve this scaling, simple detectors and high-density multiplexing are essential. We are addressing this long-term challenge through the development of frequency-multiplexed superconducting microresonator detector arrays. These arrays use lumped-element, direct-absorption resonators patterned from titanium nitride films. We will discuss our progress toward constructing a scalable 350 micron pathfinder instrument focusing on fabrication simplicity, multiplexing density, and ultimately a low per-pixel cost.

Discovery of the correspondence between intra-cluster radio emission and a high pressure region detected through the Sunyaev-Zel'dovich effect

We analyzed new 237 MHz and 614 MHz GMRT data of the most X-ray luminous galaxy cluster, RX J1347-1145. Our radio results are compared with the MUSTANG 90 GHz Sunyaev-Zel’dovich effect map and with re-processed Chandra and XMM-Newton archival data of this cluster. We point out for the first time in an unambiguous way the correspondence between a radio excess in a diffuse intracluster radio source and a hot region detected through both Sunyaev-Zel’dovich effect and X-ray observations. Our result indicates that electron re-acceleration in the excess emission of the radio mini-halo at the center of RX J1347-1145 is most likely related to a shock front propagating into the intra-cluster medium.

RADIO SOURCES FROM A 31 GHz SKY SURVEY WITH THE SUNYAEV-ZEL'DOVICH ARRAY

We present the rst sample of 31-GHz selected sources to ux levels of 1 mJy. From late 2005 to mid 2007, the Sunyaev-Zel’dovich Array (SZA) observed 7.7 square degrees of the sky at 31 GHz to a median rms of 0:18 mJy=beam. We identify 209 sources at greater than 5 signicance in the 31 GHz maps, ranging in ux from 0.7 mJy to 200 mJy. Archival NVSS data at 1.4 GHz and observations at 5 GHz with the Very Large Array are used to characterize the sources. We determine the maximumlikelihood integrated source count to be N (>S ) = (27:2 2:5 ) deg 2 (SmJy) 1:18 0:12 over the ux range 0 :7 15 mJy. This result is signicantly higher than predictions based on 1.4-GHz selected samples, a discrepancy which can be explained by a small shift in the spectral index distribution for faint 1.4 GHz sources. From comparison with previous measurements of sources within the central arcminute of massive clusters, we derive an overdensity of 6:8 4:4, relative to eld sources. Subject headings: techniques: interferometric, catalogs, surveys, cosmology: cosmic microwave background, cosmology: observations, radio continuum: general