All Outputs (376)

LLAMA: normal star formation efficiencies of molecular gas in the centres of luminous Seyfert galaxies (2017)
Journal Article
Rosario, D., Burtscher, L., Davies, R., Koss, M., Ricci, C., Lutz, D., …Veilleux, S. (2018). LLAMA: normal star formation efficiencies of molecular gas in the centres of luminous Seyfert galaxies. Monthly Notices of the Royal Astronomical Society, 473(4), 5658-5679. https://doi.org/10.1093/mnras/stx2670

Using new Atacama Pathfinder Experiment and James Clerk Maxwell Telescope spectroscopy of the CO 2→1 line, we undertake a controlled study of cold molecular gas in moderately luminous (Lbol = 1043–44.5 erg s−1) active galactic nuclei (AGN) and inacti... Read More about LLAMA: normal star formation efficiencies of molecular gas in the centres of luminous Seyfert galaxies.

CANDELS: Elevated Black Hole Growth in the Progenitors of Compact Quiescent Galaxies at z ∼ 2 (2017)
Journal Article
Kocevski, D. D., Barro, G., Faber, S., Dekel, A., Somerville, R. S., Young, J. A., Williams, C. C., McIntosh, D. H., Georgakakis, A., Hasinger, G., Nandra, K., Civano, F., Alexander, D. M., Almaini, O., Conselice, C. J., Donley, J. L., Ferguson, H. C., Giavalisco, M., Grogin, N. A., Hathi, N., …Yan, H. (2017). CANDELS: Elevated Black Hole Growth in the Progenitors of Compact Quiescent Galaxies at z ∼ 2. Astrophysical Journal, 846(2), Article 112. https://doi.org/10.3847/1538-4357/aa8566

X-Ray Spectral Analyses of AGNs from the 7Ms Chandra Deep Field-South Survey: The Distribution, Variability, and Evolutions of AGN Obscuration (2017)
Journal Article
Liu, T., Tozzi, P., Wang, J., Brandt, W. N., Vignali, C., Xue, Y., …Risaliti, G. (2017). X-Ray Spectral Analyses of AGNs from the 7Ms Chandra Deep Field-South Survey: The Distribution, Variability, and Evolutions of AGN Obscuration. Astrophysical Journal Supplement, 232(1), Article 8. https://doi.org/10.3847/1538-4365/aa7847

We present a detailed spectral analysis of the brightest active galactic nuclei (AGNs) identified in the 7Ms Chandra Deep Field-South (CDF-S) survey over a time span of 16 years. Using a model of an intrinsically absorbed power-law plus reflection, w... Read More about X-Ray Spectral Analyses of AGNs from the 7Ms Chandra Deep Field-South Survey: The Distribution, Variability, and Evolutions of AGN Obscuration.

The NuSTAR Serendipitous Survey: Hunting for the Most Extreme Obscured AGN at >10 keV (2017)
Journal Article
Lansbury, G., Alexander, D., Aird, J., Gandhi, P., Stern, D., Koss, M., …Zappacosta, L. (2017). The NuSTAR Serendipitous Survey: Hunting for the Most Extreme Obscured AGN at >10 keV. Astrophysical Journal, 846(1), Article 20. https://doi.org/10.3847/1538-4357/aa8176

We identify sources with extremely hard X-ray spectra (i.e., with photon indices of ${\rm{\Gamma }}\lesssim 0.6$) in the 13 deg2 NuSTAR serendipitous survey, to search for the most highly obscured active galactic nuclei (AGNs) detected at $\gt 10\,\m... Read More about The NuSTAR Serendipitous Survey: Hunting for the Most Extreme Obscured AGN at >10 keV.

The mean star formation rates of unobscured QSOs: searching for evidence of suppressed or enhanced star formation (2017)
Journal Article
Stanley, F., Alexander, D., Harrison, C., Rosario, D., Wang, L., Aird, J., …Smith, M. (2017). The mean star formation rates of unobscured QSOs: searching for evidence of suppressed or enhanced star formation. Monthly Notices of the Royal Astronomical Society, 472(2), 2221-2240. https://doi.org/10.1093/mnras/stx2121

We investigate the mean star formation rates (SFRs) in the host galaxies of ∼3000 optically selected quasi-stellar objects (QSOs) from the Sloan Digital Sky Survey within the Herschel-ATLAS fields, and a radio-luminous subsample covering the redshift... Read More about The mean star formation rates of unobscured QSOs: searching for evidence of suppressed or enhanced star formation.

Galaxy-scale Bars in Late-type Sloan Digital Sky Survey Galaxies Do Not Influence the Average Accretion Rates of Supermassive Black Holes (2017)
Journal Article
Goulding, A., Matthaey, E., Greene, J., Hickox, R., Alexander, D., Forman, W., …Oulmakki, M. (2017). Galaxy-scale Bars in Late-type Sloan Digital Sky Survey Galaxies Do Not Influence the Average Accretion Rates of Supermassive Black Holes. Astrophysical Journal, 843(2), Article 135. https://doi.org/10.3847/1538-4357/aa755b

Galaxy-scale bars are expected to provide an effective means for driving material toward the central region in spiral galaxies, and possibly feeding supermassive black holes (BHs). Here we present a statistically complete study of the effect of bars... Read More about Galaxy-scale Bars in Late-type Sloan Digital Sky Survey Galaxies Do Not Influence the Average Accretion Rates of Supermassive Black Holes.

Galactic Sources Detected in the NuSTAR Serendipitous Survey (2017)
Journal Article
Tomsick, J. A., Lansbury, G. B., Rahoui, F., Clavel, M., Fornasini, F. M., Hong, J., …Stern, D. (2017). Galactic Sources Detected in the NuSTAR Serendipitous Survey. Astrophysical Journal Supplement, 230(2), Article 25. https://doi.org/10.3847/1538-4365/aa7517

The Nuclear Spectroscopic Telescope Array (NuSTAR) provides an improvement in sensitivity at energies above 10 keV by two orders of magnitude over non-focusing satellites, making it possible to probe deeper into the Galaxy and universe. Lansbury and... Read More about Galactic Sources Detected in the NuSTAR Serendipitous Survey.

Black Hole Growth Is Mainly Linked to Host-galaxy Stellar Mass Rather Than Star Formation Rate (2017)
Journal Article
Yang, G., Chen, C., Vito, F., Brandt, W., Alexander, D., Luo, B., …Wang, J. (2017). Black Hole Growth Is Mainly Linked to Host-galaxy Stellar Mass Rather Than Star Formation Rate. Astrophysical Journal, 842(2), Article 72. https://doi.org/10.3847/1538-4357/aa7564

We investigate the dependence of black-hole accretion rate (BHAR) on host-galaxy star formation rate (SFR) and stellar mass (M∗) in the CANDELS/GOODS-South field in the redshift range of 0.5≤z<2.0. Our sample consists of ≈18000 galaxies, allowing us...

The VLA-COSMOS 3 GHz Large Project: AGN and host-galaxy properties out to z ≲ 6 (2017)
Journal Article
Delvecchio, I., Smolčić, V., Zamorani, G., Lagos, C. D. P., Berta, S., Delhaize, J., …Tasca, L. (2017). The VLA-COSMOS 3 GHz Large Project: AGN and host-galaxy properties out to z ≲ 6. Astronomy & Astrophysics, 602, Article A3. https://doi.org/10.1051/0004-6361/201629367

We explore the multiwavelength properties of AGN host galaxies for different classes of radio-selected AGN out to z ≲ 6 via a multiwavelength analysis of about 7700 radio sources in the COSMOS field. The sources were selected with the Very Large Arra... Read More about The VLA-COSMOS 3 GHz Large Project: AGN and host-galaxy properties out to z ≲ 6.

An ALMA Survey of Submillimeter Galaxies in the Extended Chandra Deep Field South: Spectroscopic Redshifts (2017)
Journal Article
Danielson, A., Swinbank, A., Smail, I., Simpson, J., Casey, C., Chapman, S., …van der Werf, P. (2017). An ALMA Survey of Submillimeter Galaxies in the Extended Chandra Deep Field South: Spectroscopic Redshifts. Astrophysical Journal, 840(2), Article 78. https://doi.org/10.3847/1538-4357/aa6caf

We present spectroscopic redshifts of {\text{}}{S}870μ {{m}} ≳ 2 mJy submillimeter galaxies (SMGs), which have been identified from the ALMA follow-up observations of 870 μm detected sources in the Extended Chandra Deep Field South (the ALMA-LESS sur... Read More about An ALMA Survey of Submillimeter Galaxies in the Extended Chandra Deep Field South: Spectroscopic Redshifts.

AGN-host connection at 0.5 < z < 2.5: A rapid evolution of AGN fraction in red galaxies during the last 10 Gyr (2017)
Journal Article
Wang, T., Elbaz, D., Alexander, D., Xue, Y., Gabor, J., Juneau, S., …Gu, Q. (2017). AGN-host connection at 0.5 < z < 2.5: A rapid evolution of AGN fraction in red galaxies during the last 10 Gyr. Astronomy & Astrophysics, 601, Article A63. https://doi.org/10.1051/0004-6361/201526645

We explore the dependence of the incidence of moderate-luminosity (L0.5−8 keV = 1041.9−43.7 erg s-1) active galactic nuclei (AGNs) and the distribution of their accretion rates on host color at 0.5 1010 M⊙. We use extinction-corrected rest-frame U−V... Read More about AGN-host connection at 0.5 < z < 2.5: A rapid evolution of AGN fraction in red galaxies during the last 10 Gyr.

The NuSTAR Hard X-Ray Survey of the Norma Arm Region (2017)
Journal Article
Fornasini, F. M., Tomsick, J. A., Hong, J., Gotthelf, E. V., Bauer, F., Rahoui, F., …Zhang, W. W. (2017). The NuSTAR Hard X-Ray Survey of the Norma Arm Region. Astrophysical Journal Supplement, 229(2), Article 33. https://doi.org/10.3847/1538-4365/aa61fc

We present a catalog of hard X-ray sources in a square-degree region surveyed by the Nuclear Spectroscopic Telescope Array (NuSTAR) in the direction of the Norma spiral arm. This survey has a total exposure time of 1.7 Ms, and the typical and maximum... Read More about The NuSTAR Hard X-Ray Survey of the Norma Arm Region.

The X-ray and mid-infrared luminosities in luminous type 1 quasars (2017)
Journal Article
Chen(陳建廷), C. J., Hickox, R. C., Goulding, A. D., Stern, D., Assef, R., Kochanek, C. S., …Rovilos, E. (2017). The X-ray and mid-infrared luminosities in luminous type 1 quasars. Astrophysical Journal, 837(2), Article 145. https://doi.org/10.3847/1538-4357/837/2/145

Several recent studies have reported different intrinsic correlations between the active galactic nucleus (AGN) mid-IR luminosity (${L}_{\mathrm{MIR}}$) and the rest-frame 2–10 keV luminosity (L X) for luminous quasars. To understand the origin of th... Read More about The X-ray and mid-infrared luminosities in luminous type 1 quasars.

Cosmic X-ray surveys of active galactic nuclei: The synergy between X-ray and infrared observations (2017)
Journal Article
Alexander, D. (2017). Cosmic X-ray surveys of active galactic nuclei: The synergy between X-ray and infrared observations. Astronomical Notes, 338(2-3), 172-177. https://doi.org/10.1002/asna.201713326

We briefly review the synergy between X-ray and infrared observations for active galactic nuclei (AGNs) detected in cosmic X-ray surveys, primarily with XMM-Newton, Chandra, and NuSTAR. We focus on two complementary aspects of this X-ray–infrared syn... Read More about Cosmic X-ray surveys of active galactic nuclei: The synergy between X-ray and infrared observations.

Hard X-Ray-selected AGNs in Low-mass Galaxies from the NuSTAR Serendipitous Survey (2017)
Journal Article
Chen (陳建廷), C., Brandt, W., Reines, A., Lansbury, G., Stern, D., Alexander, D., …Trump, J. (2017). Hard X-Ray-selected AGNs in Low-mass Galaxies from the NuSTAR Serendipitous Survey. Astrophysical Journal, 837(1), Article 48. https://doi.org/10.3847/1538-4357/aa5d5b

We present a sample of 10 low-mass active galactic nuclei (AGNs) selected from the 40-month NuSTAR serendipitous survey. The sample is selected to have robust NuSTAR detections at 3−24~keV, to be at z<0.3, and to have optical r-band magnitudes at lea...

A new, faint population of X-ray transients (2017)
Journal Article
Bauer, F. E., Treister, E., Schawinski, K., Schulze, S., Luo, B., Alexander, D. M., …Yang, G. (2017). A new, faint population of X-ray transients. Monthly Notices of the Royal Astronomical Society, 467(4), 4841-4857. https://doi.org/10.1093/mnras/stx417

We report on the detection of a remarkable new fast high-energy transient found in the Chandra Deep Field-South, robustly associated with a faint (mR = 27.5 mag, zph ∼ 2.2) host in the CANDELS survey. The X-ray event is comprised of 115 +12−11 −11+12... Read More about A new, faint population of X-ray transients.

A New Compton-thick AGN in our Cosmic Backyard: Unveiling the Buried Nucleus in NGC 1448 with NuSTAR (2017)
Journal Article
Annuar, A., Alexander, D., Gandhi, P., Lansbury, G., Asmus, D., Ballantyne, D., …Zhang, W. (2017). A New Compton-thick AGN in our Cosmic Backyard: Unveiling the Buried Nucleus in NGC 1448 with NuSTAR. Astrophysical Journal, 836(2), Article 165. https://doi.org/10.3847/1538-4357/836/2/165

NGC 1448 is one of the nearest luminous galaxies (L8−1000μm> 109L⊙) to ours (z = 0.00390), and yet the active galactic nucleus (AGN) it hosts was only recently discovered, in 2009. In this paper, we present an analysis of the nuclear source across th... Read More about A New Compton-thick AGN in our Cosmic Backyard: Unveiling the Buried Nucleus in NGC 1448 with NuSTAR.

The weak Fe fluorescence line and long-term X-ray evolution of the Compton-thick active galactic nucleus in NGC 7674 (2017)
Journal Article
Gandhi, P., Annuar, A., Lansbury, G., Stern, D., Alexander, D., Bauer, F., …Zhang, W. (2017). The weak Fe fluorescence line and long-term X-ray evolution of the Compton-thick active galactic nucleus in NGC 7674. Monthly Notices of the Royal Astronomical Society, 467(4), 4606-4621. https://doi.org/10.1093/mnras/stx357

We present NuSTAR X-ray observations of the active galactic nucleus (AGN) in NGC 7674. The source shows a flat X-ray spectrum, suggesting that it is obscured by Compton-thick gas columns. Based upon long-term flux dimming, previous work suggested the... Read More about The weak Fe fluorescence line and long-term X-ray evolution of the Compton-thick active galactic nucleus in NGC 7674.

The NuSTAR Serendipitous Survey: The 40-month Catalog and the Properties of the Distant High-Energy X-ray Source Population (2017)
Journal Article
Lansbury, G., Stern, D., Aird, J., Alexander, D., Fuentes, C., Harrison, F., …Zhang, W. (2017). The NuSTAR Serendipitous Survey: The 40-month Catalog and the Properties of the Distant High-Energy X-ray Source Population. Astrophysical Journal, 836(1), Article 99. https://doi.org/10.3847/1538-4357/836/1/99

We present the first full catalog and science results for the NuSTAR serendipitous survey. The catalog incorporates data taken during the first 40 months of NuSTAR operation, which provide ~20Ms of effective exposure time over 331 fields, with an are... Read More about The NuSTAR Serendipitous Survey: The 40-month Catalog and the Properties of the Distant High-Energy X-ray Source Population.

Angular momentum evolution of galaxies over the past 10 Gyr: a MUSE and KMOS dynamical survey of 400 star-forming galaxies from z = 0.3 to 1.7 (2017)
Journal Article
Swinbank, M., Harrison, C., Trayford, J., Schaller, M., Smail, I., Schaye, J., …Stott, J. (2017). Angular momentum evolution of galaxies over the past 10 Gyr: a MUSE and KMOS dynamical survey of 400 star-forming galaxies from z = 0.3 to 1.7. Monthly Notices of the Royal Astronomical Society, 467(3), 3140-3159. https://doi.org/10.1093/mnras/stx201

We present a MUSE and KMOS dynamical study 405 star-forming galaxies at redshift z = 0.28–1.65 (median redshift z¯= 0.84). Our sample is representative of the star-forming “main-sequence”, with star-formation rates of SFR = 0.1–30M⊙ yr−1 and stellar... Read More about Angular momentum evolution of galaxies over the past 10 Gyr: a MUSE and KMOS dynamical survey of 400 star-forming galaxies from z = 0.3 to 1.7.