Browsing by Author "Civano, Francesca"

Now showing 1 - 20 of 21
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    Finding rare AGN: X-ray number counts of Chandra sources in Stripe 82.
    (2013) LaMassa, Stephanie M.; Treister, Ezequiel; Urry, C. Meg; Glikman, Eilat; Cappelluti, N.; Civano, Francesca; Comastri, A.; Böhringer, Hans; Cardamone, Carie; Chon, Gayoung; Kephart, Miranda
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    Finding rare AGN: XMM-Newton and Chandra observations of SDSS Stripe 82.
    (2013) LaMassa, Stephanie M.; Treister, Ezequiel; Urry, C. Meg; Cappelluti, N.; Civano, Francesca; Ranalli, Piero; Glikman, Eilat; Richards, Gordon; Ballantyne, David; Stern, Daniel; Comastri, A.
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    On R-W1 as A Diagnostic to Discover Obscured Active Galactic Nuclei in Wide-area X-Ray Surveys.
    (2016) LaMassa, Stephanie M.; Treister, Ezequiel; Civano, Francesca; Brusa, Marcella; Stern, Daniel; Glikman, Eilat; Gallagher, Sarah; Urry, C. Meg
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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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    Probing black hole accretion tracks, scaling relations, and radiative efficiencies from stacked X-ray active galactic nuclei
    (2020) Shankar, Francesco; Weinberg, David H.; Marsden, Christopher; Grylls, Philip J.; Bernardi, Mariangela; Yang, Guang; Moster, Benjamin; Fu, Hao; Carraro, Rosamaria; Alexander, David M.; Allevato, Viola; Ananna, Tonima T.; Bongiorno, Angela; Calderone, Giorgio; Civano, Francesca; Daddi, Emanuele; Delvecchio, Ivan; Duras, Federica; La Franca, Fabio; Lapi, Andrea; Lu, Youjun; Menci, Nicola; Mezcua, Mar; Ricci, Federica; Rodighiero, Giulia; Sheth, Ravi K.; Suh, Hyewon; Villforth, Carolin; Zanisi, Lorenzo
    The masses of supermassive black holes at the centres of local galaxies appear to be tightly correlated with the mass and velocity dispersions of their galactic hosts. However, the local M-bh-M-star relation inferred from dynamically measured inactive black holes is up to an order-of-magnitude higher than some estimates from active black holes, and recent work suggests that this discrepancy arises from selection bias on the sample of dynamical black hole mass measurements. In this work, we combine X-ray measurements of the mean black hole accretion luminosity as a function of stellar mass and redshift with empirical models of galaxy stellar mass growth, integrating over time to predict the evolving M-bh-M-star relation. The implied relation is nearly independent of redshift, indicating that stellar and black hole masses grow, on average, at similar rates. Matching the de-biased local M-bh-M-star relation requires a mean radiative efficiency epsilon greater than or similar to 0.15, in line with theoretical expectations for accretion on to spinning black holes. However, matching the 'raw' observed relation for inactive black holes requires epsilon similar to 0.02, far below theoretical expectations. This result provides independent evidence for selection bias in dynamically estimated black hole masses, a conclusion that is robust to uncertainties in bolometric corrections, obscured active black hole fractions, and kinetic accretion efficiency. For our fiducial assumptions, they favour moderate-to-rapid spins of typical supermassive black holes, to achieve epsilon similar to 0.12-0.20. Our approach has similarities to the classic Soltan analysis, but by using galaxy-based data instead of integrated quantities we are able to focus on regimes where observational uncertainties are minimized.
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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 bolometric output and host-galaxy properties of obscured AGN in the XMM-COSMOS survey.
    (2011) Lusso, E.; Treister, Ezequiel; Comastri, A.; Vignali, C.; Zamorani, G.; Sanders, David B.; Bolzonella, M.; Bongiorno, A.; Brusa, Marcella; Civano, Francesca; Gilli, R.
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    The Chandra COSMOS Legacy Survey: Energy Spectrum of the Cosmic X-Ray Background and Constraints on Undetected Populations
    (2017) Cappelluti, N.; Treister, Ezequiel; Li, Yanxia; Ricarte, Angelo; Agarwal, Bhaskar; Allevato, Viola; Ananna, Tonima; Ajello, Marco; Civano, Francesca; Comastri, A.; Elvis, Martin
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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 Chandra COSMOS-Legacy Survey: Source X-Ray Spectral Properties
    (2016) Marchesi, Stefano; Treister, Ezequiel; Lanzuisi, G.; Civano, Francesca; Iwasawa, K.; Suh, H.; Comastri, A.; Zamorani, G.; Allevato, Viola; Griffiths, R.; Miyaji, T.
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    The Chandra COSMOS-Legacy Survey: The z>3 Sample
    (2016) Marchesi, Stefano; Treister, Ezequiel; Civano, Francesca; Salvato, M.; Shankar, F.; Comastri, A.; Elvis, Martin; Lanzuisi, G.; Trakhtenbrot, Benny; Vignali, C.; Zamorani, G.; Allevato, Viola
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    The NuSTAR Extragalactic Survey: Average Broadband X-Ray Spectral Properties of the NuSTAR-detected AGNs
    (2017) Del Moro, A.; Bauer, Franz Erik; Treister, Ezequiel; Ricci, Claudio; Alexander, D. M.; Aird, J. A.; Civano, Francesca; Mullaney, J.; Ballantyne, D. R.; Brandt, W N.; Comastri, A.
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    The NuSTAR Extragalactic Surveys: Initial Results and Catalog from the Extended Chandra Deep Field South
    (2015) Mullaney, J.; Bauer, Franz Erik; Treister, Ezequiel; Del Moro, A.; Aird, J. A.; Alexander, D. M.; Civano, Francesca; Hickox, R. C.; Lansbury, George B.; Ajello, Marco; Assef, R.
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    The Nustar Extragalactic Surveys: Overview and Catalog from the COSMOS Field
    (2015) Civano, Francesca; Bauer, Franz Erik; Luo, B.; Saez, C.; Treister, Ezequiel; Hickox, R. C.; Puccetti, S.; Comastri, A.; Mullaney, J.; Zappacosta, L.; LaMassa, Stephanie M.
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    The NuSTAR Extragalactic Surveys: Source Catalog and the Compton-thick Fraction in the UDS Field.
    (2018) Masini, A.; Treister, Ezequiel; Civano, Francesca; Comastri, A.; Fornasini, F.; Ballantyne, D. R.; Lansbury, George B.; Alexander, D. M.; Boorman, P.G.; Brandt, W N.
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    The NuSTAR Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-Ray Background
    (2016) Harrison, F. A.; Bauer, Franz Erik; Treister, Ezequiel; Aird, J. A.; Civano, Francesca; Lansbury, George B.; Mullaney, J.; Ballantyne, D. R.; Alexander, D. M.; Stern, Daniel; Ajello, Marco
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    The NuSTAR Extragalactic Surveys: X-Ray Spectroscopic Analysis of the Bright Hard-band Selected Sample
    (2018) Zappacosta, L.; Ricci, Claudio; Treister, Ezequiel; Comastri, A.; Civano, Francesca; Puccetti, S.; Fiore, F.; Aird, J. A.; Del Moro, A.; Lansbury, George B.; Lanzuisi, G.
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    The NuSTAR Serendipitous Survey: The 80 Month Catalog and Source Properties of the High-energy Emitting Active Galactic Nucleus and Quasar Population
    (2024) Greenwell, Claire L.; Klindt, Lizelke; Lansbury, George B.; Rosario, David J.; Alexander, David M.; Aird, James; Stern, Daniel; Forster, Karl; Koss, Michael J.; Bauer, Franz E.; Ricci, Claudio; Tomsick, John; Brandt, William N.; Connor, Thomas; Boorman, Peter G.; Annuar, Adlyka; Ballantyne, David R.; Chen, Chien-Ting; Civano, Francesca; Comastri, Andrea; Fawcett, Victoria A.; Fornasini, Francesca M.; Gandhi, Poshak; Harrison, Fiona; Heida, Marianne; Hickox, Ryan; Kammoun, Elias S.; Lanz, Lauranne; Marchesi, Stefano; Noirot, Gael; Romero-Colmenero, Encarni; Treister, Ezequiel; Urry, C. Megan; Vaisanen, Petri; van Soelen, Brian
    We present a catalog of hard X-ray serendipitous sources detected in the first 80 months of observations by the Nuclear Spectroscopic Telescope Array (NuSTAR). The NuSTAR serendipitous survey 80 month (NSS80) catalog has an unprecedented similar to 62 Ms of effective exposure time over 894 unique fields (a factor of 3 increase over the 40 month catalog, NSS40), with an areal coverage of similar to 36 deg(2), larger than all NuSTAR extragalactic surveys. NSS80 provides 1274 hard X-ray sources in the 3-24 keV band (822 new detections compared to the previous NSS40). Approximately 76% of the NuSTAR sources have lower-energy (<10 keV) X-ray counterparts from Chandra, XMM-Newton, and Swift-XRT. We have undertaken an extensive campaign of ground-based spectroscopic follow-up to obtain new source redshifts and classifications for 427 sources. Combining these with existing archival spectroscopy provides redshifts for 550 NSS80 sources, of which 547 are classified. The sample is primarily composed of active galactic nuclei (AGNs), detected over a large range in redshift (z = 0.012-3.43), but also includes 58 spectroscopically confirmed Galactic sources. In addition, five AGN-galaxy pairs, one dual AGN system, one BL Lac candidate, and a hotspot of 4C 74.26 (radio quasar) have been identified. The median rest-frame 10-40 keV luminosity and redshift of NSS80 are < L10-40 keV > = 1.2 x 10(44) erg s(-1) and < z > = 0.56. We investigate the optical properties and construct composite optical spectra to search for subtle signatures not present in the individual spectra, finding an excess of redder BL AGNs compared to optical quasar surveys, predominantly due to the presence of the host galaxy and, at least in part, due to dust obscuration.