581 citations · 5.2k across the 118 of their papers we have counts for
22 papers · 1 filter
Systematic Monitoring of Extreme X-ray Variability from Weak-line Quasars
Madison Reich, W. N. Brandt, Bin Luo +5
We present the results of a multi-cycle Chandra program to systematically monitor the X-ray variability of 10 weak-line quasars (WLQs) that previously had limited multi-epoch X-ray…
The Advanced X-ray Imaging Satellite (AXIS) Community Science Book
Michael Koss, Nafisa Aftab, Steven W. Allen +395
The AXIS Community Science Book represents the collective effort of 592 scientists worldwide to define the transformative science enabled by the Advanced X-ray Imaging Satellite (A…
The Remarkable X-ray Spectra and Variability of the Ultraluminous Weak-Line Quasar SDSS J1521+5202
Shouyi Wang, W. Niel Brandt, Bin Luo +4
We present a focused X-ray and multiwavelength study of the ultraluminous weak-line quasar (WLQ) SDSS J1521+5202, one of the few X-ray weak WLQs that is amenable to basic X-ray spe…
The X-ray enhancements of radio-loud quasars at high redshift: New results at
Zihao Zuo, Shifu Zhu, W. N. Brandt +4
Highly radio-loud quasars (HRLQs; ) at show apparent enhanced X-ray emission compared to matched HRLQs at lower redshifts, perhaps due to a redshift-depend…
Surveying the onset and evolution of supermassive black holes at high-z with AXIS
Nico Cappelluti, Adi Foord, Stefano Marchesi +8
The nature and origin of supermassive black holes (SMBHs) remain an open matter of debate within the scientific community. While various theoretical scenarios have been proposed, e…
X-ray properties and obscured fraction of AGN in the J1030 Chandra field
Matilde Signorini, Stefano Marchesi, Roberto Gilli +13
The 500ks Chandra ACIS-I observation of the field around the quasar SDSS J1030+0524 is currently the 5th deepest extragalactic X-ray survey. The rich multi-band coverage o…
X-ray Unveiling Events in a z~1.6 Active Galactic Nucleus in the 7 Ms Chandra Deep Field-South
Li-Ming Yu, Bin Luo, William N. Brandt +14
We investigate the extreme X-ray variability of a z = 1.608 active galactic nucleus in the 7 Ms Chandra Deep Field-South (XID 403), which showed two significant X-ray brightening e…
The universal shape of the X-ray variability power spectrum of AGN up to
M. Paolillo, I. E. Papadakis, W. N. Brandt +12
We study the ensemble X-ray variability properties of Active Galactic Nuclei (AGN) over a large range of timescales (20 ks 14 yrs), redshift (), lu…
An X-ray fading, UV brightening QSO at
Fabio Vito, Marco Mignoli, Roberto Gilli +13
Explaining the existence of SMBHs at is a persistent challenge to modern astrophysics. Multi-wavelength observations of QSOs revea…
The Stellar Age Dependence of X-ray Emission from Normal Star-Forming Galaxies in the GOODS Fields
Woodrow Gilbertson, Bret Lehmer, Keith Doore +11
The Chandra Deep Field-South and North surveys (CDFs) provide unique windows into the cosmic history of X-ray emission from normal (non-active) galaxies. Scaling relations of norma…
A magnetar-powered X-ray transient as the aftermath of a binary neutron-star merger
Y. Q. Xue, X. C. Zheng, Y. Li +14
Neutron star-neutron star mergers are known to be associated with short gamma-ray bursts. If the neutron star equation of state is sufficiently stiff, at least some of such mergers…
Electromagnetic Window into the Dawn of Black Holes
Zoltán Haiman, William N. Brandt, Alexey Vikhlinin +28
Massive 10^6-10^10 Msun black holes (BHs) are ubiquitous in local galactic nuclei. They were common by the time the Universe is several Gyr old, and many of them were in place with…
Variability-selected low-luminosity active galactic nuclei candidates in the 7 Ms Chandra Deep Field-South
N. Ding, B. Luo, W. N. Brandt +13
In deep X-ray surveys, active galactic nuclei (AGNs) with a broad range of luminosities have been identified. However, cosmologically distant low-luminosity AGN (LLAGN, $L_{\mathrm…
Tracing the accretion history of supermassive Black Holes through X-ray variability: results from the Chandra Deep Field-South
M. Paolillo, I. Papadakis, W. N. Brandt +15
We study the X-ray variability properties of distant AGNs in the Chandra Deep Field-South region over 17 years, up to , and compare them with those predicted by models bas…
Black-Hole Growth is Mainly Linked to Host-Galaxy Stellar Mass rather than Star Formation Rate
G. Yang, C. -T. J. Chen, F. Vito +14
We investigate the dependence of black-hole accretion rate (BHAR) on host-galaxy star formation rate (SFR) and stellar mass () in the CANDELS/GOODS-South field in the redshift…
High-Redshift AGNs and the Next Decade of Chandra and XMM-Newton
W. N. Brandt, F. Vito
We briefly review how X-ray observations of high-redshift active galactic nuclei (AGNs) at z = 4-7 have played a critical role in understanding their basic demographics as well as…
Long-Term X-ray Variability of Typical Active Galactic Nuclei in the Distant Universe
G. Yang, W. Brandt, B. Luo +13
We perform long-term ( yr, observed-frame) X-ray variability analyses of the 68 brightest radio-quiet active galactic nuclei (AGNs) in the 6 Ms Deep Field-Sou…
Chandra counterparts of CANDELS GOODS-S sources
N. Cappelluti, A. Comastri, A. Fontana +18
Improving the capabilities of detecting faint X-ray sources is fundamental to increase the statistics on faint high-z AGN and star-forming galaxies. We performed a simultaneous Max…
The XMM deep survey in the CDF-S VIII. X-ray properties of the two brightest sources
K. Iwasawa, C. Vignali, A. Comastri +7
We present results from the deep XMM-Newton observations of the two brightest X-ray sources in the Chandra Deep Field South (CDFS), PID 203 (z=0.544) and PID 319 (z=0.742). The lon…
The Hot and Energetic Universe: The formation and growth of the earliest supermassive black holes
James Aird, Andrea Comastri, Marcella Brusa +18
A crucial challenge in astrophysics over the coming decades will be to understand the origins of supermassive black holes (SMBHs) that lie at the centres of most, if not all, galax…
The Hot and Energetic Universe: A White Paper presenting the science theme motivating the Athena+ mission
Kirpal Nandra, Didier Barret, Xavier Barcons +237
This White Paper, submitted to the recent ESA call for science themes to define its future large missions, advocates the need for a transformational leap in our understanding of tw…
The XMM Deep survey in the CDFS V. Iron K lines from active galactic nuclei in the distant Universe
S. Falocco, F. J. Carrera, A. Corral +11
X-ray spectroscopy of active galactic nuclei (AGN) offers the opportunity to directly probe the inner regions of the accretion disk. We present the results of our analysis of avera…