169 citations · 2.6k across the 55 of their papers we have counts for
52 papers
The Compton-thick AGN Population and the Distribution of Low-mass AGN in our Cosmic Backyard
A. Annuar, D. M. Alexander, P. Gandhi +21
We present a census of the Compton-thick (CT) active galactic nucleus (AGN) population and the column density () distribution of AGN in our cosmic backyard using a mid-…
The NuSTAR Local AGN Distribution Survey (NuLANDS) I: Towards a Truly Representative Column Density Distribution in the Local Universe
Peter G. Boorman, Poshak Gandhi, Johannes Buchner +33
Hard X-ray-selected samples of Active Galactic Nuclei (AGN) provide one of the cleanest views of supermassive black hole accretion, but are biased against objects obscured by Compt…
The NuSTAR Serendipitous Survey: the 80-month catalog and source properties of the high-energy emitting AGN and quasar population
Claire L. Greenwell, Lizelke Klindt, George B. Lansbury +32
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 serendipi…
A population of Optically Quiescent Quasars from WISE and SDSS
Claire Greenwell, Poshak Gandhi, Daniel Stern +4
The growth of active galactic nuclei (AGN) occurs under some form of obscuration in a large fraction of the population. The difficulty in constraining this population leads to high…
The Complex X-ray Obscuration Environment in the Radio Loud Type 2 Quasar 3C 223
Stephanie M. LaMassa, Tahir Yaqoob, Panayiotis Tzanavaris +4
3C 223 is a radio loud, Type 2 quasar at with an intriguing XMM-Newton spectrum that implicated it as a rare, Compton-thick ( cm$^…
Discovery of 24 radio-bright quasars at using low-frequency radio observations
A. J. Gloudemans, K. J. Duncan, A. Saxena +18
High redshift quasars () that also shine brightly at radio wavelengths are unique signposts of supermassive black hole activity in the early universe. However, bright radio so…
NuSTAR observations of a heavily X-ray obscured AGN in the dwarf galaxy J144013+024744
Shrey. Ansh, Chien-Ting J. Chen, W. N. Brandt +10
We present a multi-wavelength analysis of the dwarf Seyfert-2 galaxy J, a candidate obscured active galactic nucleus (AGN) thought to be powered by an intermediate-m…
XMM-Newton and NuSTAR Observations of an Optically Quiescent Quasar
Claire Greenwell, Poshak Gandhi, George Lansbury +3
Optically quiescent quasars (OQQs) represent a recently systematised class of infrared-luminous active galactic nuclei (AGN) which have galaxy-like optical continua. They may repre…
Quasar Feedback Survey: Multi-phase outflows, turbulence and evidence for feedback caused by low power radio jets inclined into the galaxy disk
A. Girdhar, C. M. Harrison, V. Mainieri +18
We present a study of a luminous, z=0.15, type-2 quasar (log [L([OIII])/(erg/s)]=42.8) from the Quasar Feedback Survey. It is classified as 'radio-quiet' (log [L(1.4 GHz)/(W/Hz)]=2…
Investigating the Nature of the Luminous Ambiguous Nuclear Transient ASASSN-17jz
Thomas W. -S. Holoien, Jack M. M. Neustadt, Patrick J. Vallely +31
We present observations of the extremely luminous but ambiguous nuclear transient (ANT) ASASSN-17jz, spanning roughly 1200 days of the object's evolution. ASASSN-17jz was discovere…
A hard X-ray view of Luminous and Ultra-luminous Infrared Galaxies in GOALS: I - AGN obscuration along the merger sequence
C. Ricci, G. C. Privon, R. W. Pfeifle +25
The merger of two or more galaxies can enhance the inflow of material from galactic scales into the close environments of Active Galactic Nuclei (AGN), obscuring and feeding the su…
A Highly Accreting Low-Mass Black Hole Hidden in the Dust: Suzaku and NuSTAR observations of the NLS1 Mrk 1239
Jiachen Jiang, Mislav Baloković, Murray Brightman +3
We present torus modelling for the X-ray spectra of a nearby narrow-line Seyfert 1 galaxy Mrk 1239 (), based on archival Suzaku, NuSTAR and Swift observations. Our model…
A candidate Optically Quiescent Quasar lacking narrow emission lines
Claire Greenwell, Poshak Gandhi, Daniel Stern +5
Many Active Galactic Nuclei (AGN) surveys rely on optical emission line signatures for robust source classification. There are, however, examples of luminous AGN candidates lacking…
The Quasar Feedback Survey: Discovering hidden Radio-AGN and their connection to the host galaxy ionised gas
M. E. Jarvis, C. M. Harrison, V. Mainieri +18
We present the first results from the Quasar Feedback Survey, a sample of 42 z<0.2, [O III] luminous AGN (L[O III]>10^42.1 ergs/s) with moderate radio luminosities (i.e. L(1.4GHz)>…
A New Transient Ultraluminous X-ray Source in NGC 7090
D. J. Walton, M. Heida, M. Bachetti +17
We report on the discovery of a new, transient ultraluminous X-ray source (ULX) in the galaxy NGC 7090. This new ULX, which we refer to as NGC 7090 ULX3, was discovered via monitor…
High molecular gas content and star formation rates in local galaxies that host quasars, outflows and jets
M. E. Jarvis, C. M. Harrison, V. Mainieri +11
We use a sample of powerful z~0.1 type 2 quasars ('obscured'; log[L(AGN)/erg/s]>~45), which host kiloparsec-scale ionized outflows and jets, to identify possible signatures of AGN…
Observations of Four Nearby X-ray Faint AGN: Low Luminosity or Heavy Obscuration?
A. Annuar, D. M. Alexander, P. Gandhi +20
We present observations of four active galactic nuclei (AGN) located within 15 Mpc. These AGN, namely ESO 121-G6, NGC 660, NGC 3486 and NGC 5195, have observed X-ray lumin…
The Hunt for Pulsating Ultraluminous X-ray Sources
X. Song, D. J. Walton, G. B. Lansbury +4
Motivated by the recent discoveries that six Ultraluminous X-ray Sources (ULXs) are powered by highly super-Eddington X-ray pulsars, we searched for additional pulsating ULX (PULX)…
X-ray Observations of Luminous Dusty Quasars at z > 2
G. B. Lansbury, M. Banerji, A. C. Fabian +1
We present new X-ray observations of luminous heavily dust-reddened quasars (HRQs) selected from infrared sky surveys. HRQs appear to be a dominant population at high redshifts and…
Prevalence of radio jets associated with galactic outflows and feedback from quasars
M. E. Jarvis, C. M. Harrison, A. P. Thomson +7
We present 1-7 GHz high-resolution radio imaging (VLA and e-MERLIN) and spatially-resolved ionized gas kinematics for ten z<0.2 type~2 `obscured' quasars (log [L(AGN)/(erg/s)]>~45)…
A new class of flares from accreting supermassive black holes
Benny Trakhtenbrot, Iair Arcavi, Claudio Ricci +26
Accreting supermassive black holes (SMBHs) can exhibit variable emission across the electromagnetic spectrum and over a broad range of timescales. The variability of active galacti…
The Multiple Merger Assembly of a Hyper-luminous Obscured Quasar at redshift 4.6
T. Diaz-Santos, R. J. Assef, A. W. Blain +10
Galaxy mergers and gas accretion from the cosmic web drove the growth of galaxies and their central black holes at early epochs. We report spectroscopic imaging of a multiple merge…
Chandra Observations of NuSTAR Serendipitous Sources near the Galactic Plane
John A. Tomsick, George B. Lansbury, Farid Rahoui +8
The NuSTAR serendipitous survey has already uncovered a large number of Active Galactic Nuclei (AGN), providing new information about the composition of the Cosmic X-ray Background…
NuSTAR and Keck Observations of Heavily Obscured Quasars Selected by WISE
Wei Yan, Ryan C. Hickox, Kevin N. Hainline +15
A primary aim of the Nuclear Spectroscopic Telescope Array (NuSTAR) mission is to find and characterize heavily obscured Active Galactic Nuclei (AGNs). Based on mid-infrared photom…