Michael D. Joner

SPACE TELESCOPE AND OPTICAL REVERBERATION MAPPING PROJECT. III. OPTICAL CONTINUUM EMISSION AND BROADBAND TIME DELAYS IN NGC 5548

The LBT is an international collaboration among institutions in the United States, Italy and Germany. LBT Corporation partners are: The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota and University of Virginia; The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University. This paper used data obtained with the MODS spectrographs built with funding from National Science Foundation (NSF) grant AST-9987045 and the NSF Telescope System Instrumentation Program (TSIP), with additional funds from the Ohio Board of Regents and the Ohio State University Office of Research. This paper made use of the modsIDL spectral data reduction pipeline developed in part with funds provided by NSF Grant AST - 1108693. The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. KAIT and its ongoing operation were made possible by donations from Sun Microsystems, Inc., the Hewlett-Packard Company, AutoScope Corporation, Lick Observatory, the NSF, the University of California, the Sylvia and Jim Katzman Foundation, and the TABASGO Foundation. Research at Lick Observatory is partially supported by a generous gift from Google. Support for HST program number GO-13330 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. M.M.F., G.D.R., B.M.P., C.J.G., and R.W.P. are grateful for the support of the NSF through grant AST- 1008882 to The Ohio State University. A.J.B. and L.P. have been supported by NSF grant AST-1412693. A.V.F. and W.- K.Z. are grateful for financial assistance from NSF grant AST- 1211916, the TABASGO Foundation, and the Christopher R. Redlich Fund. M.C. Bentz gratefully acknowledges support through NSF CAREER grant AST-1253702 to Georgia State University. M.C. Bottorff acknowledges HHMI for support through an undergraduate science education grant to Southwestern University. K.D.D. is supported by an NSF Fellowship awarded under grant AST-1302093. R.E. gratefully acknowledges support from NASA under awards NNX13AC26G, NNX13AC63G, and NNX13AE99G. J.M.G. gratefully acknowledges support from NASA under award NNH13CH61C. P.B.H. is supported by NSERC. M.I. acknowledges support from the Creative Initiative program, No. 2008-0060544, of the National Research Foundation of Korea (NRFK) funded by the Korean government (MSIP). M.D.J. acknowledges NSF grant AST-0618209 used for obtaining the 0.91 m telescope at WMO. SRON is financially supported by NWO, the Netherlands Organization for Scientific Research. B.C.K. is partially supported by the UC Center for Galaxy Evolution. C.S.K. acknowledges the support of NSF grant AST-1009756. D.C.L. acknowledges support from NSF grants AST-1009571 and AST-1210311, under which part of this research (photometric observations collected at MLO) was carried out. We thank Nhieu Duong, Harish Khandrika, Richard Mellinger, J. Chuck Horst, Steven Armen, and Eddie Garcia for assistance with the MLO observations. P.L. acknowledges support from Fondecyt grant #1120328. A.P. acknowledges support from a NSF graduate fellowship, a UCSB Dean’s Fellowship, and a NASA Einstein Fellowship. J.S.S. acknowledges CNPq, National Council for Scientific and Technological Development (Brazil) for partial support and The Ohio State University for warm hospitality. T.T. has been supported by NSF grant AST-1412315. T.T. and B.C.K. acknowledge support from the Packard Foundation in the form of a Packard Research Fellowship to T.T.; also, T.T. thanks the American Academy in Rome and the Observatory of Monteporzio Catone for kind hospitality. The Dark Cosmology Centre is funded by the Danish National Research Foundation. M.V. gratefully acknowledges support from the Danish Council for Independent Research via grant no. DFF–4002-00275. J.-H.W. acknowledges support by the National Research Foundation of Korea (NRF) grant funded by the Korean government (No. 2010-0027910). E.D.B. is supported by Padua University through grants 60A02-5857/13, 60A02-5833/14, 60A02-4434/15, and CPDA133894. K.H. acknowledges support from STFC grant ST/M001296/1. S.A.K. thanks Dr. I. A. Rakhimov, the Director of Svetloe Observatory, for his support and hospitality. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.

The lick agn monitoring project 2011: Fe II reverberation from the outer broad-line region

The prominent broad Fe II emission blends in the spectra of active galactic nuclei have been shown to vary in response to continuum variations, but past attempts to measure the reverberation lag time of the optical Fe II lines have met with only limited success. Here we report the detection of Fe II reverberation in two Seyfert 1 galaxies, NGC 4593 and Mrk 1511, based on data from a program carried out at Lick Observatory in Spring 2011. Light curves for emission lines including Hβ and Fe II were measured by applying a fitting routine to decompose the spectra into several continuum and emission-line components, and we use cross-correlation techniques to determine the reverberation lags of the emission lines relative to V-band light curves. In both cases, the measured lag (τcen) of Fe II is longer than that of Hβ, although the inferred lags are somewhat sensitive to the choice of Fe II template used in the fit. For spectral decompositions done using the Fe II template of Veron-Cetty et al., we find τcen (Fe II)/τcen (Hβ) = 1.9 ± 0.6 in NGC 4593 and 1.5 ± 0.3 in Mrk 1511. The detection of highly correlated variations between Fe II and continuum emission demonstrates that the Fe II emission in these galaxies originates in photoionized gas, located predominantly in the outer portion of the broad-line region.

A new Large Magellanic Cloud K-band distance from precision measurements of nearby red clump stars

High-precision (sigma < 0.01) new JHK observations of 226 of the brightest and nearest red clump stars in the solar neighbourhood are used to determine distance moduli for the LMC. The resulting K- and H-band values of 18.47\pm0.02 and 18.49\pm0.06 imply that any correction to the K-band Cepheid PL relation due to metallicity differences between Cepheids in the LMC and in the solar neighborhood must be quite small.

The lick AGN monitoring project 2011: Dynamical modeling of the broad-line region in Mrk 50

We present dynamical modeling of the broad-line region (BLR) in the Seyfert 1 galaxy Mrk 50 using reverberation mapping data taken as part of the Lick AGN Monitoring Project (LAMP) 2011. We model the reverberation mapping data directly, constraining the geometry and kinematics of the BLR, as well as deriving a black hole mass estimate that does not depend on a normalizing factor or virial coefficient. We find that the geometry of the BLR in Mrk 50 is a nearly face-on thick disk, with a mean radius of 9.6^(+1.2)_(–0.9) light days, a width of the BLR of 6.9^(+1.2)_(–1.1) light days, and a disk opening angle of 25 ± 10 deg above the plane. We also constrain the inclination angle to be 9^(+7)_(–5) deg, close to face-on. Finally, the black hole mass of Mrk 50 is inferred to be log_(10)(M_(BH)/M_☉) = 7.57^(+0.44)_(–0.27). By comparison to the virial black hole mass estimate from traditional reverberation mapping analysis, we find the normalizing constant (virial coefficient) to be log_(10) f = 0.78^(+0.44)_(–0.27), consistent with the commonly adopted mean value of 0.74 based on aligning the M_(BH)-σ* relation for active galactic nuclei and quiescent galaxies. While our dynamical model includes the possibility of a net inflow or outflow in the BLR, we cannot distinguish between these two scenarios.

BROAD-LINE REVERBERATION IN THE KEPLER-FIELD SEYFERT GALAXY Zw 229-015

The Seyfert 1 galaxy Zw 229-015 is among the brightest active galaxies being monitored by the Kepler mission. In order to determine the black hole mass in Zw 229-015 from Hβ reverberation mapping, we have carried out nightly observations with the Kast Spectrograph at the Lick 3 m telescope during the dark runs from 2010 June through December, obtaining 54 spectroscopic observations in total. We have also obtained nightly V-band imaging with the Katzman Automatic Imaging Telescope at Lick Observatory and with the 0.9 m telescope at the Brigham Young University West Mountain Observatory over the same period. We detect strong variability in the source, which exhibited more than a factor of two change in broad Hβ flux. From cross-correlation measurements, we find that the Hβ light curve has a rest-frame lag of 3.86+0.69 –0.90 days with respect to the V-band continuum variations. We also measure reverberation lags for Hα and Hγ and find an upper limit to the Hδ lag. Combining the Hβ lag measurement with a broad Hβ width of σline = 1590 ± 47 km s–1 measured from the rms variability spectrum, we obtain a virial estimate of M BH = 1.00+0.19 –0.24 × 107 M ☉ for the black hole in Zw 229-015. As a Kepler target, Zw 229-015 will eventually have one of the highest-quality optical light curves ever measured for any active galaxy, and the black hole mass determined from reverberation mapping will serve as a benchmark for testing relationships between black hole mass and continuum variability characteristics in active galactic nuclei.

The Lick AGN Monitoring Project 2011: Reverberation Mapping of Markarian 50

The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 weeks in spring 2011. Here we present the first results from this program, a measurement of the broad-line reverberation lag in the Seyfert 1 galaxy Mrk 50. Combining our data with supplemental observations obtained prior to the start of the main observing campaign, our data set covers a total duration of 4.5 months. During this time, Mrk 50 was highly variable, exhibiting a maximum variability amplitude of a factor of ~4 in the U-band continuum and a factor of ~2 in the Hβ line. Using standard cross-correlation techniques, we find that Hβ and Hγ lag the V-band continuum by τ_(cen) = 10.64^(+0.82)_(–0.93) and 8.43^(+1.30)_(–1.28) days, respectively, while the lag of He II λ4686 is unresolved. The Hβ line exhibits a symmetric velocity-resolved reverberation signature with shorter lags in the high-velocity wings than in the line core, consistent with an origin in a broad-line region (BLR) dominated by orbital motion rather than infall or outflow. Assuming a virial normalization factor of f = 5.25, the virial estimate of the black hole mass is (3.2 ± 0.5) × 10^7 M_☉. These observations demonstrate that Mrk 50 is among the most promising nearby active galaxies for detailed investigations of BLR structure and dynamics.

Multiwavelength Monitoring of the BL Lacertae Object PKS 2155–304 in 1994 May. I. The Ground-based Campaign

Optical, near-infrared, and radio observations of the BL Lac object PKS 2155-304 were obtained simultaneously with a continuous UV/EUV/X-ray monitoring campaign in 1994 May. Further optical observations were gathered throughout most of 1994. The radio, millimeter, and near-infrared data show no strong correlations with the higher energies. The optical light curves exhibit flickering of 0.2-0.3 mag on timescales of 1-2 days, superposed on longer timescale variations. Rapid variations of ~0.01 mag minute-1, if real, are the fastest seen to date for any BL Lac object. Small (0.2-0.3 mag) increases in the V and R bands occur simultaneously with a flare seen at higher energies. All optical wave bands (UBVRI) track each other well over the period of observation, with no detectable delay. For most of the period the average colors remain relatively constant, although there is a tendency for the colors (in particular, B-V) to vary more when the source fades. In polarized light, PKS 2155-304 showed strong color dependence (polarization increases toward the blue, PU/PI = 1.31) and the highest optical polarization (U = 14.3%) ever observed for this source. The polarization variations trace the flares seen in the UV flux. For the fastest variability timescale observed, we estimate a central black hole mass of 1.5 × 109(δ/10) M☉, consistent with UV and X-ray constraints and smaller than previously calculated for this object.

A giant planet undergoing extreme-ultraviolet irradiation by its hot massive-star host

The amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. Of the thousands of extrasolar planets now known, only six have been found that transit hot, A-type stars (with temperatures of 7,300–10,000 kelvin), and no planets are known to transit the even hotter B-type stars. For example, WASP-33 is an A-type star with a temperature of about 7,430 kelvin, which hosts the hottest known transiting planet, WASP-33b (ref. 1); the planet is itself as hot as a red dwarf star of type M (ref. 2). WASP-33b displays a large heat differential between its dayside and nightside, and is highly inflated–traits that have been linked to high insolation. However, even at the temperature of its dayside, its atmosphere probably resembles the molecule-dominated atmospheres of other planets and, given the level of ultraviolet irradiation it experiences, its atmosphere is unlikely to be substantially ablated over the lifetime of its star. Here we report observations of the bright star HD 195689 (also known as KELT-9), which reveal a close-in (orbital period of about 1.48 days) transiting giant planet, KELT-9b. At approximately 10,170 kelvin, the host star is at the dividing line between stars of type A and B, and we measure the dayside temperature of KELT-9b to be about 4,600 kelvin. This is as hot as stars of stellar type K4 (ref. 5). The molecules in K stars are entirely dissociated, and so the primary sources of opacity in the dayside atmosphere of KELT-9b are probably atomic metals. Furthermore, KELT-9b receives 700 times more extreme-ultraviolet radiation (that is, with wavelengths shorter than 91.2 nanometres) than WASP-33b, leading to a predicted range of mass-loss rates that could leave the planet largely stripped of its envelope during the main-sequence lifetime of the host star.

A Catalog of Temperatures and Red Cousins Photometry for the Hyades

Using Hyades photometry published by Mendoza and other authors, Pinsonneault et al. have recently concluded that Cousins V - I photometry published by Taylor & Joner is not on the Cousins system. Extensive tests of the Taylor-Joner photometry and other pertinent results are therefore performed in this paper. It is found that in part, the Pinsonneault et al. conclusion rests on (1) a systematic error in Mendozas (R - I)J photometry and (2) a small error in an approximate Johnson-to-Cousins transformation published by Bessell. For the Taylor-Joner values of (V - R)C, it is found that there are possible (though not definite) differences of several mmag with other results. However, the Taylor-Joner values of (R - I)C data are supported at the 1 mmag level. Using the (R - I)C data and other published results, an (R - I)C catalog is assembled for 146 Hyades stars with spectral types earlier than about K5. For single stars with multiple contributing data, the rms errors of the catalog entries are less than 4.4 mmag. Temperatures on the Di Benedetto angular-diameter scale are also given in the catalog and are used to help update published analyses of high-dispersion values of [Fe/H] for the Hyades. The best current mean Hyades value of [Fe/H] is found to be +0.103 ± 0.008 dex and is essentially unchanged from its previous value. In addition to these numerical results, recommendations are made about improving attitudes and practices that are pertinent to issues like those raised by Pinsonneault et al.

TIME-SERIES ENSEMBLE PHOTOMETRY OF SX PHOENICIS STARS. I. BL CAMELOPARDALIS

We present an analysis of the multiperiodic SX Phoenicis star BL Camelopardalis (GD 428). Along with 24 times of maximum light from archival data, six previously unpublished times of maximum light from photomultiplier observations and 39 new CCD observations of maximum light are reported. The new CCD observations indicate that BL Cam is a double-mode variable with a primary period of 0.0391 day, a secondary period of 0.0306 day, and a π1/ π0 ratio of 0.783. The relation between metallicity and period ratio for large amplitude δ Scuti variables is examined in detail. Finally, evidence is presented that the fundamental period π0 has increased by 0.009 seconds in the last 20 years.