Browsing by Author "Urry, C. Megan"

Now showing 1 - 20 of 23
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    Accretion History of AGNs. II. Constraints on AGN Spectral Parameters Using the Cosmic X-Ray Background
    (2020) Ananna, Tonima; Treister, Ezequiel; Urry, C. Megan; Ricci, Claudio; Hickox, R. C.; Padmanabhan, Nikhil; Marchesi, Stefano; Kirkpatrick, Allison
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    BASS. XXXV. The MBH-σ* Relation of 105 Month Swift-BAT Type 1 AGNs
    (IOP Publishing Ltd, 2023) Caglar, Turgay; Koss, Michael J.; Burtscher, Leonard; Trakhtenbrot, Benny; Erdim, M. Kiyami; Mejia-Restrepo, Julian E.; Ricci, Federica; Powell, Meredith C.; Ricci, Claudio; Mushotzky, Richard; Bauer, Franz Erik; Ananna, Tonima T.; Baer, Rudolf E.; Brandl, Bernhard; Brinchmann, Jarle; Harrison, Fiona; Ichikawa, Kohei; Kakkad, Darshan; Oh, Kyuseok; Riffel, Rogerio; Sartori, Lia F.; Smith, Krista L.; Stern, Daniel; Urry, C. Megan
    We present two independent measurements of stellar velocity dispersions (sigma(star)) from the Ca II H+K lambda 3969, 3934 and Mg I b lambda 5183, 5172, 5167 region (3880-5550 angstrom) and the calcium triplet region (8350-8750 angstrom) for 173 hard X-ray-selected Type 1 active galactic nuclei (AGNs; z <= 0.08) from the 105 month Swift-BAT catalog. We construct one of the largest samples of local Type 1 AGNs that have both single-epoch virial black hole mass (M-BH) estimates and sigma(star) measurements obtained from high spectral resolution data, allowing us to test the usage of such methods for supermassive black hole studies. We find that the two independent sigma(star) measurements are highly consistent with each other, with an average offset of only 0.002 +/- 0.001 dex. Comparing M-BH estimates based on broad emission lines and stellar velocity dispersion measurements, we find that the former is systematically lower by approximate to 0.12 dex. Consequently, Eddington ratios estimated through broad-line MBH determinations are similarly biased (but in the opposite way). We argue that the discrepancy is driven by extinction in the broad-line region. We also find an anticorrelation between the offset from the M-BH-sigma(star) relation and the Eddington ratio. Our sample of Type 1 AGNs shows a shallower M-BH-sigma(star) relation (with a power-law exponent of approximate to 3.5) compared with that of inactive galaxies (with a power-law exponent of approximate to 4.5), confirming earlier results obtained from smaller samples.
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    Do Moderate-Luminosity Active Galactic Nuclei Suppress Star Formation?
    (2009) Schawinski, Kevin; Treister, Ezequiel; Virani, Shanil; Simmons, Brooke D.; Urry, C. Megan; Kaviraj, Sugata; Kushkuley, Bronika
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    Extended X-ray emission in the IC 2497 - Hanny's Voorwerp system: energy injection in the gas around a fading AGN.
    (2016) Sartori, Lia F.; Schawinski, Kevin; Koss, M.; Treister, Ezequiel; Maksym, W. Peter; Keel, William C.; Urry, C. Megan; Lintott, Chris J.; Wong, O. Ivy
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    Lyα Emission-Line Galaxies at z = 3.1 in the Extended Chandra Deep Field-South.
    (2007) Gronwall, C.; Infante Lira, Leopoldo; Orsi Moyano, Alvaro; Treister, Ezequiel; Ciardullo, Robin; Hickey, Thomas; Gawiser, Eric; Feldmeier, John J.; van Dokkum, Pieter G.; Urry, C. Megan; Herrera, David
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    Morphological Parameters and Associated Uncertainties for 8 Million Galaxies in the Hyper Suprime-Cam Wide Survey
    (Wiley, 2023) Ghosh, Aritra; Urry, C. Megan; Mishra, Aayush; Perreault-Levasseur, Laurence; Natarajan, Priyamvada; Sanders, David B.; Nagai, Daisuke; Tian, Chuan; Cappelluti, Nico; Kartaltepe, Jeyhan S.; Powell, Meredith C.; Rau, Amrit; Treister, Ezequiel
    We use the Galaxy Morphology Posterior Estimation Network (GaMPEN) to estimate morphological parameters and associated uncertainties for & SIM;8 million galaxies in the Hyper Suprime-Cam Wide survey with z & LE; 0.75 and m & LE; 23. GaMPEN is a machine-learning framework that estimates Bayesian posteriors for a galaxy's bulge-to-total light ratio (L ( B )/L ( T )), effective radius (R ( e )), and flux (F). By first training on simulations of galaxies and then applying transfer learning using real data, we trained GaMPEN with <1% of our data set. This two-step process will be critical for applying machine-learning algorithms to future large imaging surveys, such as the Rubin-Legacy Survey of Space and Time, the Nancy Grace Roman Space Telescope, and Euclid. By comparing our results to those obtained using light profile fitting, we demonstrate that GaMPEN's predicted posterior distributions are well calibrated (& LSIM;5% deviation) and accurate. This represents a significant improvement over light profile fitting algorithms, which underestimate uncertainties by as much as & SIM;60%. For an overlapping subsample, we also compare the derived morphological parameters with values in two external catalogs and find that the results agree within the limits of uncertainties predicted by GaMPEN. This step also permits us to define an empirical relationship between the Sersic index and L ( B )/L ( T ) that can be used to convert between these two parameters. The catalog presented here represents a significant improvement in size (& SIM;10x), depth (& SIM;4 mag), and uncertainty quantification over previous state-of-the-art bulge+disk decomposition catalogs. With this work, we also release GaMPEN's source code and trained models, which can be adapted to other data sets.
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    Optical Spectroscopy of X-Ray Sources in the Extended Chandra Deep Field South
    (2009) Treister, Ezequiel; Virani, Shanil; Gawiser, Eric.; Urry, C. Megan; Lira, Paulina; Francke Henríquez, Harold Johanns Phillippe; Blanc, Guillermo; Cardamone, Carolin N.; Damen, Maaike; Taylor, Edward N.; Schawinski, Kevin
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    Peering Through the Dust: NuSTAR Observations of Two FIRST-2MASS Red Quasars
    (2016) LaMassa, Stephanie M.; Treister, Ezequiel; Ricarte, Angelo; Glikman, Eilat; Urry, C. Megan; Stern, Daniel.; Yaqoob, Tahir; Lansbury, George B.; Civano, Francesca; Boggs, Steve E.; Brandt, W N.
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    The 31 Deg2 Release of the Stripe 82 X-Ray Survey: The Point Source Catalog
    (2016) LaMassa, Stephanie M.; Treister, Ezequiel; Urry, C. Megan; Cappelluti N; Böhringer, Hans; Comastri, A.; Glikman, Eilat; Richards, Gordon; Ananna, Tonima; Brusa, Marcella; Cardamone, Carie
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    The Accretion History of AGN: The Spectral Energy Distributions of X-Ray-luminous Active Galactic Nuclei
    (2023) Auge, Connor; Sanders, David; Treister, Ezequiel; Urry, C. Megan; Kirkpatrick, Allison; Cappelluti, Nico; Ananna, Tonima Tasnim; Boquien, Médéric; Baloković, Mislav; Civano, Francesca; Coleman, Brandon; Ghosh, Aritra; Kartaltepe, Jeyhan; Koss, Michael; LaMassa, Stephanie; Marchesi, Stefano; Peca, Alessandro; Powell, Meredith; Trakhtenbrot, Benny; Turner, Tracey Jane
    Spectral energy distributions (SEDs) from X-ray to far-infrared (FIR) wavelengths are presented for a sample of 1246 X-ray-luminous active galactic nuclei (AGNs; L0.5–10 keV > 1043 erg s−1), with zspec < 1.2, selected from Stripe 82X, COSMOS, and GOODS-N/S. The rest-frame SEDs show a wide spread (∼2.5 dex) in the relative strengths of broad continuum features at X-ray, ultraviolet (UV), mid-infrared (MIR), and FIR wavelengths. A linear correlation (log–log slope of 0.7 ± 0.04) is found between LMIR and LX. There is significant scatter in the relation between the LUV and LX owing to heavy obscuration; however, the most luminous and unobscured AGNs show a linear correlation (log–log slope of 0.8 ± 0.06) in the relation above this scatter. The relation between LFIR and LX is predominantly flat, but with decreasing dispersion at LX > 1044 erg s−1. The ratio between the "galaxy-subtracted" bolometric luminosity and the intrinsic LX increases from a factor of ∼10 to 70 from log Lbol/(erg s−1) = 44.5 to 46.5. Characteristic SED shapes have been determined by grouping AGNs based on relative strengths of the UV and MIR emission. The average L1μm is constant for the majority of these SED shapes, while AGNs with the strongest UV and MIR emission have elevated L1μm, consistent with the AGN emission dominating their SEDs at optical and near-infrared wavelengths. A strong correlation is found between the SED shape and both the LX and Lbol, such that Lbol/LX = 20.4 ± 1.8, independent of the SED shape. This is consistent with an evolutionary scenario of increasing Lbol with decreasing obscuration as the AGN blows away circumnuclear gas.
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    The Accretion History of AGNs. I. Supermassive Black Hole Population Synthesis Model
    (2019) Ananna, Tonima; Treister, Ezequiel; Urry, C. Megan; Ricci, Claudio; Kirkpatrick, Allison; LaMassa, Stephanie M.; Buchner, Johannes; Civano, Francesca; Tremmel, Michael; Marchesi, Stefano
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    The Calán-Yale Deep Extragalactic Research (CYDER) Survey: Optical Properties and Deep Spectroscopy of Serendipitous X-Ray Sources
    (2005) Treister, Ezequiel; Gawiser, Eric.; Castander, Francisco J.; Maccarone, Thomas J.; Coppi, Paolo S.; Urry, C. Megan; Maza, José; Herrera, David; Gonzalez, Valentino; Montoya, Carlos; Pineda, Pedro
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    The Chandra COSMOS Legacy survey: optical/IR identifications
    (2016) Marchesi, Stefano; Treister, Ezequiel; Civano, Francesca; Elvis, Martin; Salvato, M.; Brusa, Marcella; Comastri, A.; Gilli, R.; Hasinger, G.; Lanzuisi, G.; Miyaji, T.; Urry, C. Megan
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    The Chandra Cosmos Legacy Survey: Overview and Point Source Catalog
    (2016) Civano, Francesca; Treister, Ezequiel; Marchesi, Stefano; Comastri, A.; Urry, C. Megan; Elvis, Martin; Cappelluti N; Puccetti, S.; Brusa, Marcella; Zamorani, G.; Hasinger, G.
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    The Cosmic History of Black Hole Growth from Deep Multiwavelength Surveys.
    (2012) Treister, Ezequiel; Urry, C. Megan
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    The Evolution of Obscuration in Active Galactic Nuclei
    (2006) Treister, Ezequiel; Urry, C. Megan
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    The extended chandra deep field-south survey : X-Ray point-source catalog.
    (2006) Virani, Shanil; Treister, Ezequiel; Urry, C. Megan; Gawiser, Eric.
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    The green valley is a red herring : Galaxy Zoo reveals two evolutionary pathways towards quenching of star formation in early- and late-type galaxies.
    (2014) Schawinski, Kevin; Treister, Ezequiel; Urry, C. Megan; Simmons, Brooke D.; Fortson, Lucy; Kaviraj, Sugata; Keel, William C.; Lintott, Chris J.; Masters, K. L.; Nichol, Robert C.; Sarzi, Marc
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    The Hunt for Red Quasars: Luminous Obscured Black Hole Growth Unveiled in the Stripe 82 X-Ray Survey
    (2017) LaMassa, Stephanie M.; Lira, Paulina; Treister, Ezequiel; Glikman, Eilat; Brusa, Marcella; Rigby, Jane R.; Ananna, Tonima; Stern, Daniel.; Urry, C. Megan; Salvato, M.; Alexandroff, Rachael
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    The Multiwavelength Survey by Yale-Chile (MUSYC): Deep Medium-band Optical Imaging and High-quality 32-band Photometric Redshifts in the ECDF-S
    (2010) Cardamone, Carolin N.; Gawiser, Eric.; Treister, Ezequiel; van Dokkum, Pieter G.; Urry, C. Megan; Taniguchi, Yoshi; Brammer, Gabriel; Taylor, Edward N.; Damen, Maaike; Cobb, Bethany E.