Physical Sciences and Mathematics Commons^™

A Deep Look At The Nuclear Region Of Ugc 5101 Through High Angular Resolution Mid-Ir Data With Gtc/Canaricam, M. Martínez-Paredes, Almudena Alonso-Herrero, Itziar Aretxaga, C. Ramos Almeida, A. Hernán-Caballero, O. González-Martín, M. Pereira-Santaella, Christopher Packham, A. Asensio Ramos, T. Díaz-Santos, Moshe Elitzur, P. Esquej, I. García-Bernete, Masatoshi Imanishi, Nancy A. Levenson, José Miguel Rodríguez Espinosa

Physics and Astronomy Faculty Publications

We present an analysis of the nuclear infrared (IR, 1.6–18 μm) emission of the ultraluminous IR galaxy UGC 5101 to derive the properties of its active galactic nucleus (AGN) and its obscuring material. We use new mid-IR high angular resolution (0.3–0.5 arcsec) imaging using the Si-2 filter (λ_C = 8.7 μm) and 7.5–13 μm spectroscopy taken with CanariCam (CC) on the 10.4 m Gran Telescopio CANARIAS. We also use archival Hubble Space Telescope/NICMOS and Subaru/COMICS imaging and Spitzer/IRS spectroscopy. We estimate the near- and mid-IR unresolved nuclear emission by modelling the imaging data with GALFIT. We decompose …

Strong Variability Of The Coronal Line Region In Ngc 5548, Hermine Landt, Martin J. Ward, Katrien C. Steenbrugge, Gary J. Ferland

Physics and Astronomy Faculty Publications

We present the second extensive study of the coronal line variability in an active galaxy. Our data set for the well-studied Seyfert galaxy NGC 5548 consists of five epochs of quasi-simultaneous optical and near-infrared spectroscopy spanning a period of about five years and three epochs of X-ray spectroscopy overlapping in time with it. Whereas the broad emission lines and hot dust emission varied only moderately, the coronal lines varied strongly. However, the observed high variability is mainly due to a flux decrease. Using the optical [Fe vii] and X-ray O vii emission lines we estimate that the coronal line gas …

Gamma-Rays From The Quasar Pks 1441+25: Story Of An Escape, P. T. Reynolds, Et Al

Physical Sciences Publications

Outbursts from gamma-ray quasars provide insights on the relativistic jets of active galactic nuclei and constraints on the diffuse radiation fields that fill the universe. The detection of significant emission above 100 GeV from a distant quasar would show that some of the radiated gamma-rays escape pair-production interactions with low-energy photons, be it the extragalactic background light (EBL), or the radiation near the supermassive black hole lying at the jet's base. VERITAS detected gamma-ray emission up to ~200 GeV from PKS 1441+25 (z = 0.939) during 2015 April, a period of high activity across all wavelengths. This observation of …

The Nustar Extragalactic Survey: First Direct Measurements Of The Greater Than Or Similar To 10 Kev X-Ray Luminosity Function For Active Galactic Nuclei At Z > 0.1, J. Aird, D. M. Alexander, D. R. Ballantyne, R. C. Hickox, A. Del-Moro, R. C. Hickox, G. B. Lansbury, J. R. Mullaney, F. E. Bauer, W. N. Brandt

Dartmouth Scholarship

We present the first direct measurements of the rest-frame 10–40 keV X-ray luminosity function (XLF) of active galactic nuclei (AGNs) based on a sample of 94 sources at 0.1 < z < 3, selected at 8–24 keV energies from sources in the Nuclear Spectroscopic Telescope Array (NuSTAR) extragalactic survey program. Our results are consistent with the strong evolution of the AGN population seen in prior, lower-energy studies of the XLF. However, different models of the intrinsic distribution of absorption, which are used to correct for selection biases, give significantly different predictions for the total number of sources in our sample, leading to small, systematic differences in our binned estimates of …

The Inferred Evolution Of The Cold Gas Properties Of Candels Galaxies At 0.5 < Z < 3.0, G. Popping, K. Caputi, S. C. Trager, Rachel S. Somerville, Avishai Dekel, Susan A. Kassin, Dale D. Kocevski, Anton M. Koekemoer, Sandra M. Faber, Henry C. Ferguson, A. Galametz, Norman A. Grogin, Yicheng Guo, Y. Lu, Arjen Van Der Wel, Benjamin J. Weiner

Physics and Astronomy Faculty Publications

We derive the total cold gas, atomic hydrogen, and molecular gas masses of approximately 24 000 galaxies covering four decades in stellar mass at redshifts 0.5 < z < 3.0, taken from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey survey. Our inferences are based on the inversion of a molecular hydrogen based star formation law, coupled with a prescription to separate atomic and molecular gas. We find that: (1) there is an increasing trend between the inferred cold gas (H i and H₂), H i, and H₂ mass and the stellar mass of galaxies down to stellar masses of 10⁸ M_⊙ already in place at z = 3; (2) the molecular fractions of cold gas increase with increasing stellar mass and look-back time; (3) there is hardly any evolution in the mean H i content of galaxies at fixed stellar mass; (4) the cold gas fraction and relative amount of molecular …

Dark Matter Halo Concentration And The Evolution Of Spiral Structure In N-Body, Barred Spiral Galaxies, Jazmin Esmeralda Berlanga Medina

Graduate Theses and Dissertations

Motivated by the evidence of relationships between pitch angle (the tightness of spiral arm structure in the disk), P, and various indicators of central mass concentration, as well as the theoretical relationship between halo mass concentration and the density of visible matter in the central part of the galaxy, we look at a possible relationship between P and cvir (the virial concentration of the dark matter halo) in N-body simulations of barred, spiral galaxies. We also look at the evolution of pitch angle over time in higher temporal resolution than any data currently available in the literature. We find that …

A Determination Of The Gamma-Ray Flux And Photon Spectral Index Distributions Of Blazars From The Fermi-Lat 3lac, Jack Singal

Physics Faculty Publications

We present a determination of the distributions of gamma-ray photon flux – the so-called LogN–LogS relation – and photon spectral index for blazars, based on the third extragalactic source catalogue of the Fermi Gamma-ray Space Telescope's Large Area Telescope, and considering the photon energy range from 100 MeV to 100 GeV. The data set consists of the 774 blazars in the so-called Clean sample detected with a greater than approximately 7σ detection threshold and located above ±20° Galactic latitude. We use non-parametric methods verified in previous works to reconstruct the intrinsic distributions from the observed ones …

The Nustar Extragalactic Surveys: Overview And Catalog From The Cosmos Field, F. Civano, R. C. Hickox, S. Puccetti, A. Comastri

Dartmouth Scholarship

To provide the census of the sources contributing to the X-ray background peak above 10 keV, NuSTAR is performing extragalactic surveys using a three-tier "wedding cake" approach. We present the NuSTAR survey of the COSMOS field, the medium sensitivity and medium area tier, covering 1.7 deg2 and overlapping with both Chandra and XMM-Newton data. This survey consists of 121 observations for a total exposure of ~3 Ms. To fully exploit these data, we developed a new detection strategy, carefully tested through extensive simulations. The survey sensitivity at 20% completeness is 5.9, 2.9 and 6.4 x 10^-14 erg/cm2/s in the 3-24 …

A Critical Assessment Of Stellar Mass Measurement Methods, Bahram Mobasher, Tomas Dahlen, Henry C. Ferguson, Viviana Acquaviva, Guillermo Barro, Steven L. Finkelstein, Adriano Fontana, Ruth Gruetzbauch, Seth Johnson, Yu Lu, Casey Papovich, Janine Pforr, Mara Salvato, Rachel S. Somerville, Tommy Wiklind, Stijn Wuyts, Matthew L.N. Ashby, Eric Bell, Christopher J. Conselice, Mark E. Dickinson, Sandra M. Faber, Giovanni Fazio, Kristian Finlator, Audrey Galametz, Eric Gawiser, Mauro Giavalisco, Andrea Grazian, Norman A. Grogin, Yicheng Guo, Nimish Hathi, Dale Kocevski, Anton M. Koekemoer, David C. Koo, Jeffrey A. Newman, Naveen Reddy, Paola Santini, Risa H. Wechsler

Physics and Astronomy Faculty Publications

This is the second paper in a series aimed at investigating the main sources of uncertainty in measuring the observable parameters in galaxies from their spectral energy distributions (SEDs). In the first paper we presented a detailed account of the photometric redshift measurements and an error analysis of this process. In this paper we perform a comprehensive study of the main sources of random and systematic error in stellar mass estimates for galaxies, and their relative contributions to the associated error budget. Since there is no prior knowledge of the stellar mass of galaxies (unlike their photometric redshifts), we use …

Observational Properties Of Simulated Galaxies In Overdense And Average Regions At Redshifts Z ≃ 6–12, Hidenobu Yajima, Isaac Shlosman, Emilio Romano-Díaz, Kentaro Nagamine

Physics and Astronomy Faculty Publications

We use high-resolution zoom-in cosmological simulations of galaxies of Romano-Díaz et al., post-processing them with a panchromatic three-dimensional radiation transfer code to obtain the galaxy UV luminosity function (LF) at z ≃ 6–12. The galaxies are followed in a rare, heavily overdense region within a ∼5σ density peak, which can host high-z quasars, and in an average density region, down to the stellar mass of M_star ∼ 4 × 10⁷ M_⊙. We find that the overdense regions evolve at a substantially accelerated pace – the most massive galaxy has grown to M_star ∼ 8.4 …

Stellar Metallicity Gradients In Sdss Galaxies, Benjamin Roig, Michael R. Blanton, Renbin Yan

Physics and Astronomy Faculty Publications

We infer stellar metallicity and abundance ratio gradients for a sample of red galaxies in the Sloan Digital Sky Survey (SDSS) Main galaxy sample. Because this sample does not have multiple spectra at various radii in a single galaxy, we measure these gradients statistically. We separate galaxies into stellar mass bins, stack their spectra in redshift bins, and calculate the measured absorption-line indices in projected annuli by differencing spectra in neighboring redshift bins. After determining the line indices, we use stellar population modeling from the EZ_Ages software to calculate ages, metallicities, and abundance ratios within each annulus. Our data cover …

Supermassive Black Hole Formation At High Redshifts Via Direct Collapse In A Cosmological Context, Jun-Hwan Choi, Isaac Shlosman, Mitchell C. Begelman

Physics and Astronomy Faculty Publications

We study the early stage of the formation of seed supermassive black holes via direct collapse in dark matter (DM) haloes, in the cosmological context. We perform high-resolution zoom-in simulations of such collapse at high z. Using the adaptive mesh refinement code enzo, we resolve the formation and growth of a DM halo, until its virial temperature reaches ∼10⁴ K, atomic cooling turns on, and collapse ensues. We demonstrate that direct collapse proceeds in two stages, although they are not well separated. The first stage is triggered by the onset of atomic cooling, and leads to rapidly increasing …

Star Formation And Quenching Among The Most Massive Galaxies At Z ∼ 1.7, C. Mancini, A. Renzini, E. Daddi, G. Rodighiero, S. Berta, N. Grogin, Dale D. Kocevski, A. Koekemoer

Physics and Astronomy Faculty Publications

We have conducted a detailed object-by-object study of a mass-complete (M_* ≥ 10¹¹ M_⊙) sample of 56 galaxies at 1.4 ≤ z ≤ 2 in the Great Observatories Origins Deep Survey-South field, showing that an accurate deblending in 24 μm images is essential to properly assign to each galaxy its own star formation rate (SFR), whereas an automatic procedure often fails. This applies especially to galaxies with SFRs below the main sequence (MS) value, which may be in their quenching phase. After that, the sample splits evenly between galaxies forming stars within a factor of …

Star Formation And Relaxation In 379 Nearby Galaxy Clusters, Seth A. Cohen, Ryan C. Hickox, Gary A. Wegner

Dartmouth Scholarship

We investigate the relationship between star formation (SF) and level of relaxation in a sample of 379 galaxy clusters at z < 0.2. We use data from the Sloan Digital Sky Survey to measure cluster membership and level of relaxation, and to select star-forming galaxies based on mid-infrared emission detected with the Wide-Field Infrared Survey Explorer. For galaxies with absolute magnitudes M_r < −19.5, we find an inverse correlation between SF fraction and cluster relaxation: as a cluster becomes less relaxed, its SF fraction increases. Furthermore, in general, the subtracted SF fraction in all unrelaxed clusters (0.117 ± 0.003) is higher than that in all relaxed clusters (0.097 ± 0.005). We verify the validity of our SF calculation methods and membership criteria through analysis of previous work. Our results agree with previous findings that a weak correlation exists between cluster SF and dynamical state, possibly because unrelaxed clusters are less evolved relative to relaxed clusters.

Variability Of The Coronal Line Region In Ngc 4151, Hermine Landt, Martin J. Ward, Katrien C. Steenbrugge, Gary J. Ferland

Physics and Astronomy Faculty Publications

We present the first extensive study of the coronal line variability in an active galaxy. Our data set for the nearby source NGC 4151 consists of six epochs of quasi-simultaneous optical and near-infrared spectroscopy spanning a period of about 8 yr and five epochs of X-ray spectroscopy overlapping in time with it. None of the coronal lines showed the variability behaviour observed for the broad emission lines and hot dust emission. In general, the coronal lines varied only weakly, if at all. Using the optical [Fe vii] and X-ray O vii emission lines we estimate that the coronal line gas …

Metal-Poor, Strongly Star-Forming Galaxies In The Deep2 Survey: The Relationship Between Stellar Mass, Temperature-Based Metallicity, And Star Formation Rate, Chun Ly, Jane R. Rigby, Michael Cooper, Renbin Yan

Physics and Astronomy Faculty Publications

We report on the discovery of 28 z ≈ 0.8 metal-poor galaxies in DEEP2.

For the remainder of the abstract, please download this article or visit https://doi.org/10.1088/0004-637X/805/1/45.

The 2d Distribution Of Iron-Rich Ejecta In The Remnant Of Sn 1885 In M31, Robert A. Fesen, Peter A. Höflich, Andrew J. S. Hamilton

Dartmouth Scholarship

We present Hubble Space Telescope (HST) ultraviolet Fe i and Fe ii images of the remnant of Supernova 1885 (S And) which is observed in absorption against the bulge of the Andromeda galaxy, M31. We compare these Fe i and Fe ii absorption line images to previous HST absorption images of S And, of which the highest quality and theoretically cleanest is Ca ii H and K. Because the remnant is still in free expansion, these images provide a 2D look at the distribution of iron synthesized in this probable Type Ia explosion, thus providing insights and constraints …

P-Manga: Gradients In Recent Star Formation Histories As Diagnostics For Galaxy Growth And Death, Cheng Li, Enci Wang, Lin Lin, Matthew A. Bershady, Kevin Bundy, Christy A. Tremonti, Ting Xiao, Renbin Yan, Dmitry Bizyaev, Michael Blanton, Sabrina Cales, Brian Cherinka, Edmond Cheung, Niv Drory, Eric Emsellem, Hai Fu, Joseph Gelfand, David R. Law, Lahwai Lin, Nick Macdonald, Claudia Maraston, Karen L. Masters, Michael R. Merrifield, Kaike Pan, S. F. Sánchez, Donald P. Schneider, Daniel Thomas, David Wake, Lixin Wang, Anne-Marie Weijmans, David Wilkinson, Peter Yoachim, Kai Zhang, Tiantian Zheng

Physics and Astronomy Faculty Publications

We present an analysis of the data produced by the MaNGA prototype run (P-MaNGA), aiming to test how the radial gradients in recent star formation histories, as indicated by the 4000 Å break (D_n(4000)), Hδ absorption (EW(Hδ_A)), and Hα emission (EW(Hα)) indices, can be useful for understanding disk growth and star formation cessation in local galaxies. We classify 12 galaxies observed on two P-MaNGA plates as either centrally quiescent (CQ) or centrally star-forming (CSF), according to whether D_n(4000) measured in the central spaxel of each datacube exceeds 1.6. For …

A Wfc3 Grism Emission Line Redshift Catalog In The Goods-South Field, Aaron M. Morris, Dale D. Kocevski, Jonathan R. Trump, Benjamin J. Weiner, Nimish P. Hathi, Guillermo Barro, Tomas Dahlen, Sandra M. Faber, Steven L. Finkelstein, Adriano Fontana, Henry C. Ferguson, Norman A. Grogin, Ruth Grützbauch, Yicheng Guo, Li-Ting Hsu, Anton M. Koekemoer, David C. Koo, Bahram Mobasher, Janine Pforr, Mara Salvato, Tommy Wiklind, Stijn Wuyts

Physics and Astronomy Faculty Publications

We combine Hubble Space Telescope (HST)/Wide Field Camera3 (WFC3) imaging and G141 grism observations from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and 3D-HST surveys to produce a catalog of grism spectroscopic redshifts for galaxies in the CANDELS/GOODS-South field. The WFC3/G141 grism spectra cover a wavelength range of 1.1 ≼ λ ≼ 1.7 μm with a resolving power of R ~ 130 for point sources, thus providing rest-frame optical spectra for galaxies out to z ~ 3.5. The catalog is selected in the H-band (F160W) and includes both galaxies with and without previously …

Bootstrapping Dielectronic Recombination From Second-Row Elements And The Orion Nebula, N. R. Badnell, Gary J. Ferland, T. W. Gorczyca, D. Nikolić, Gururaj Anil Wagle

Physics and Astronomy Faculty Publications

Dielectronic recombination (DR) is the dominant recombination process for most heavy elements in photoionized clouds. Accurate DR rates for a species can be predicted when the positions of autoionizing states are known. Unfortunately such data are not available for most third- and higher-row elements. This introduces an uncertainty that is especially acute for photoionized clouds, where the low temperatures mean that DR occurs energetically through very low-lying autoionizing states. This paper discusses S²⁺ → S⁺ DR, the process that is largely responsible for establishing the [S iii]/[S ii] ratio in nebulae. We derive an empirical rate coefficient using …

Atomic Data For Zn Ɪɪ: Improving Spectral Diagnostics Of Chemical Evolution In High-Redshift Galaxies, Romas Kisielius, Varsha P. Kulkarni, Gary J. Ferland, Pavel Bogdanovich, Debopam Som, Matt L. Lykins

Physics and Astronomy Faculty Publications

Damped Lyα (DLA) and sub-DLA absorbers in quasar spectra provide the most sensitive tools for measuring the element abundances of distant galaxies. The estimation of abundances from absorption lines depends sensitively on the accuracy of the atomic data used. We have started a project to produce new atomic spectroscopic parameters for optical and UV spectral lines using state-of-the-art computer codes employing a very broad configuration interaction (CI) basis. Here we report our results for Zn ii, an ion used widely in studies of the interstellar medium (ISM) as well as DLAs and sub-DLAs. We report new calculations of many …

P-Manga: Full Spectral Fitting And Stellar Population Maps From Prototype Observations, David M. Wilkinson, Claudia Maraston, Daniel Thomas, Lodovico Coccato, Rita Tojeiro, Michele Cappellari, Francesco Belfiore, Matthew Bershady, Mike Blanton, Kevin Bundy, Sabrina Cales, Brian Cherinka, Niv Drory, Eric Emsellem, Hai Fu, David Law, Cheng Li, Roberto Maiolino, Karen Masters, Christy Tremonti, David Wake, Enci Wang, Anne-Marie Weijmans, Ting Xiao, Renbin Yan, Kai Zhang, Dmitry Bizyaev, Jonathan Brinkmann, Karen Kinemuchi, Daniel Oravetz, Kaike Pan, Audrey Simmons

Physics and Astronomy Faculty Publications

MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) is a 6-yr SDSS-IV (Sloan Digital Sky Survey IV) survey that will obtain resolved spectroscopy from 3600 to 10 300 Å for a representative sample of over 10 000 nearby galaxies. In this paper, we derive spatially resolved stellar population properties and radial gradients by performing full spectral fitting of observed galaxy spectra from P-MaNGA, a prototype of the MaNGA instrument. These data include spectra for 18 galaxies, covering a large range of morphological type. We derive age, metallicity, dust, and stellar mass maps, and their radial gradients, using high spectral-resolution stellar …

P-Manga Galaxies: Emission-Lines Properties – Gas Ionization And Chemical Abundances From Prototype Observations, F. Belfiore, R. Maiolino, K. Bundy, D. Thomas, C. Maraston, D. Wilkinson, S. F. Sánchez, M. Bershady, G. A. Blanc, M. Bothwell, S. L. Cales, L. Coccato, N. Drory, E. Emsellem, H. Fu, J. Gelfand, D. Law, K. Masters, J. Parejko, C. Tremonti, D. Wake, A. Weijmans, Renbin Yan, T. Xiao, K. Zhang, T. Zheng, K. Bizyaev, K. Kinemuchi, D. Oravetz, A. Simmons

Physics and Astronomy Faculty Publications

MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) is a 6-yr Sloan Digital Sky Survey (SDSS-IV) survey that will obtain spatially resolved spectroscopy from 3600 to 10 300 Å for a representative sample of over 10 000 nearby galaxies. In this paper, we present the analysis of nebular emission-line properties using observations of 14 galaxies obtained with P-MaNGA, a prototype of the MaNGA instrument. By using spatially resolved diagnostic diagrams, we find extended star formation in galaxies that are centrally dominated by Seyfert/LINER-like emission, which illustrates that galaxy characterizations based on single fibre spectra are necessarily incomplete. We observe extended …

The Role Of Bulge Formation In The Homogenization Of Stellar Populations At Z ~ 2 As Revealed By Internal Color Dispersion In Candels, Steven Boada, V. Tilvi, R. F. Quadri, M. Hilton, S. Finkelstein, Yicheng Guo, N. Bond, C. Conselice, A. Dekel, H. Ferguson, M. Giavalisco, N. A. Grogin, Dale D. Kocevski, A. M. Koekemoer, D. C. Koo

Physics and Astronomy Faculty Publications

We use data from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey to study how the spatial variation in the stellar populations of galaxies relates to the formation of galaxies at 1.5 < z < 3.5. We use the internal color dispersion (ICD), measured between the rest-frame UV and optical bands, which is sensitive to age (and dust attenuation) variations in stellar populations. The ICD shows a relation with the stellar masses and morphologies of the galaxies. Galaxies with the largest variation in their stellar populations as evidenced by high ICD have disk-dominated morphologies (with Sérsic indexes M/M_⊙) < 11. There is a marked decrease in the ICD as the stellar mass and/or the Sérsic index increases. By studying the relations between the ICD and other galaxy properties including size, total color, star formation rate, and dust attenuation, we conclude that the largest variations in stellar populations occur in galaxies where the light from newly, high star-forming clumps contrasts older stellar disk populations. This phase reaches a peak for galaxies only with a specific stellar mass range, 10 < log(M/M_⊙) < 11, and prior to the formation of a substantial bulge/spheroid. In contrast, galaxies at higher or lower stellar masses and/or higher Sérsic index (n > 2) show reduced ICD values, implying a greater homogeneity of their stellar populations. This indicates that if a galaxy is to have a quiescent bulge along with a star-forming disk, typical of Hubble sequence galaxies, this is most common for stellar masses 10 < log(M/M_⊙) < 11 and when the bulge component remains relatively small (n > 2).

The Differences In The Torus Geometry Between Hidden And Non-Hidden Broad Line Active Galactic Nuclei, Kohei Ichikawa, Christopher Packham, Cristina Ramos Almeida, Andrés Asensio Ramos, Almudena Alonso-Herrero, Omaira González-Martín, Enrique Lopez-Rodriguez, Yoshihiro Ueda, Tanio Díaz-Santos, Moshe Elitzur, Sebastian F. Hönig, Masatoshi Imanishi, Nancy A. Levenson, Rachel E. Mason, Eric S. Perlman, Crystal D. Alsip

Physics and Astronomy Faculty Publications

We present results from the fitting of infrared (IR) spectral energy distributions of 21 active galactic nuclei (AGNs) with clumpy torus models. We compiled high spatial resolution (~0.3–0.7 arcsec) mid-IR (MIR) N-band spectroscopy, Q-band imaging, and nuclear near- and MIR photometry from the literature. Combining these nuclear near- and MIR observations, far-IR photometry, and clumpy torus models enables us to put constraints on the torus properties and geometry. We divide the sample into three types according to the broad line region (BLR) properties: type-1s, type-2s with scattered or hidden broad line region (HBLR) previously observed, and type-2s without …

Zfourge/Candels: On The Evolution Of M* Galaxy Progenitors From Z=3 To 0.5*, C. Papovich, I. Labbé, R. Quadri, V. Tilvi, P. Behroozi, E. F. Bell, K. Glazebrook, L. Spitler, C. M.S. Straatman, K.-V. Tran, M. Cowley, R. Davé, A. Dekel, M. Dickinson, H. C. Ferguson, S. L. Finkelstein, E. Gawiser, H. Inami, S. M. Faber, G. G. Kacprzak, L. Kawinwanichakij, Dale D. Kocevski, A. Koekemoer, D. C. Koo, P. Kurczynski, J. M. Lotz, Y. Lu, R. A. Lucas, D. Mcintosh, N. Mehrtens, B. Mobasher, A. Monson, G. Morrison, T. Nanayakkara, S. E. Persson, B. Salmon, R. Simons, A. Tomczak, P. Van Dokkum, B. Weiner, S. P. Willner

Physics and Astronomy Faculty Publications

Galaxies with stellar masses near M* contain the majority of stellar mass in the universe, and are therefore of special interest in the study of galaxy evolution. The Milky Way (MW) and Andromeda (M31) have present-day stellar masses near M*, at 5 × 10¹⁰ M _☉ (defined here to be MW-mass) and 10¹¹ M _☉ (defined to be M31-mass). We study the typical progenitors of these galaxies using the FOURSTAR Galaxy Evolution Survey (ZFOURGE). ZFOURGE is a deep medium-band near-IR imaging survey, which is sensitive to the progenitors of these galaxies out to z ~ 3. …

Spitzer Space Telescope Measurements Of Dust Reverberation Lags In The Seyfert 1 Galaxy Ngc 6418, Billy Vazquez, Pasquale Galianni, Michael Richmond, Andrew Robinson, David J. Axon, Keith Horne, Triana Almeyda, Michael Fausnaugh, Bradley M. Peterson, Mark Bottorff, Jack Gallimore, Moshe Elitzur, Hagai Netzer, Thaisa Storchi-Bergmann, Alessandro Marconi, Alessandro Capetti, Dan Batcheldor, Catherine Buchanan, Giovanna Stirpe, Makoto Kishimoto, Christopher Packham, Enrique Perez, Clive Tadhunter, John Upton, Vincente Estrada-Carpenter

Physics and Astronomy Faculty Publications

We present results from a 15 month campaign of high-cadence (~3 days) mid-infrared Spitzer and optical (B and V) monitoring of the Seyfert 1 galaxy NGC 6418, with the objective of determining the characteristic size of the dusty torus in this active galactic nucleus (AGN). . . .

For the remainder of the abstract, please visit:

http://dx.doi.org/10.1088/0004-637X/801/2/127

Stellar Masses From The Candels Survey: The Goods-South And Uds Fields, P. Santini, H. C. Ferguson, A. Fontana, B. Mobasher, G. Barro, M. Castellano, S. L. Finkelstein, A. Grazian, L. T. Hsu, B. Lee, S.-K. Lee, J. Pforr, M. Salvato, T. Wiklind, S. Wuyts, O. Almaini, M. C. Cooper, A. Galametz, B. Weiner, R. Amorin, K. Boutsia, C. J. Conselice, T. Dahlen, M. E. Dickinson, M. Giavalisco, N. A. Grogin, Y. Guo, N. P. Hathi, Dale D. Kocevski, A. M. Koekemoer, P. Kurczynski, E. Merlin, A. Mortlock, J. A. Newman, D. Paris, L. Pentericci, R. Simons, S. P. Willner

Physics and Astronomy Faculty Publications

We present the public release of the stellar mass catalogs for the GOODS-S and UDS fields obtained using some of the deepest near-IR images available, achieved as part of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey project. We combine the effort from 10 different teams, who computed the stellar masses using the same photometry and the same redshifts. Each team adopted their preferred fitting code, assumptions, priors, and parameter grid. The combination of results using the same underlying stellar isochrones reduces the systematics associated with the fitting code and other choices. Thanks to the availability of different estimates, we …

The Galaxy Stellar Mass Function At 3.5 ≤ Z ≤ 7.5 In The Candels/Uds, Goods-South, And Hudf Fields, A. Grazian, A. Fontana, P. Santini, J. S. Dunlop, H. C. Ferguson, M. Castellano, R. Amorin, M. L. N. Ashby, G. Barro, P. Behroozi, K. Boutsia, K. I. Caputi, R. R. Chary, A. Dekel, M. E. Dickenson, S. M. Faber, G. G. Fazio, S. L. Finkelstein, A. Galametz, E. Giallongo, M. Giavalisco, N. A. Grogin, Y. Guo, Dale D. Kocevski, A. M. Koekemoer, D. C. Koo, K.-S. Lee, Y. Lu, E. Merlin, B. Mobasher, M. Nonino, C. Paovich, D. Paris, L. Pentericci, N. Reddy, A. Renzini, B. Salmon, M. Salvato, V. Sommariva, M. Song, E. Vanzella

Physics and Astronomy Faculty Publications

Context. The form and evolution of the galaxy stellar mass function (GSMF) at high redshifts provide crucial information on star formation history and mass assembly in the young Universe, close or even prior to the epoch of reionization.

Aims. We used the unique combination of deep optical/near-infrared/mid-infrared imaging provided by HST, Spitzer, and the VLT in the CANDELS-UDS, GOODS-South, and HUDF fields to determine the GSMF over the redshift range 3.5 ≤ z ≤ 7.5.

Methods. We used the HST WFC3/IR near-infrared imaging from CANDELS and HUDF09, reaching H ≃ 27 − 28.5 over a total area of 369 …

The Dust Geometric Distribution In Seyfert 1 And Seyfert 2 Galaxies, Isolated And In Interaction, S. Mendoza-Castrejón, D. Dultzin, Y. Krongold, J. J. González, Moshe Elitzur

Physics and Astronomy Faculty Publications

We analyse the mid-infrared (MIR) spectra of 39 Seyfert galaxies observed with the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope. Our sample consists of 19 Seyfert type 1 (Sy1) galaxies, three intermediate Seyfert galaxies and 17 type 2 Seyfert (Sy2) galaxies in the nearby Universe. This sample was extracted from a larger sample, the circumgalactic environment of which was studied in a previous work by Dultzin-Hacyan et al., who found that Sy2 objects are in interaction more frequently than normal galaxies, while Sy1s are not. In this article, we study the silicate dust distribution that dominates the …