Results 91 to 100 of about 1,130 (187)

On the Extremely X-Ray Variable Active Galactic Nuclei in the XMM-LSS Field

The Astrophysical Journal
We present a systematic investigation of extremely X-ray variable active galactic nuclei (AGNs) in the ≈5.3 deg ^2 XMM-SERVS XMM-LSS region. Eight variable AGNs are identified with rest-frame 2 keV flux density variability amplitudes around 6–12.
Zijian Zhang, Bin Luo, Linhua Jiang, W. N. Brandt, Jian Huang, Qingling Ni   +5 more
doaj   +1 more source

First Evidence for a Quasiperiodic Oscillation Triplet and Its Relativistic Precession Origin in RE J1034+396

The Astrophysical Journal
Quasiperiodic oscillations (QPOs) in active galactic nuclei (AGNs) provide a powerful tool for probing the structure of the innermost accretion flow and corona around supermassive black holes.
Ruisong Xia, Yongquan Xue, Jialai Wang, Hao Liu   +3 more
doaj   +1 more source

XRISM Spectroscopy of Accretion-driven Wind Feedback in NGC 4151

The Astrophysical Journal Letters
The hottest, most ionized, and fastest winds driven by accretion onto massive black holes have the potential to reshape their host galaxies. Calorimeter-resolution X-ray spectroscopy is the ideal tool to understand this feedback mode, as it enables ...
Xin Xiang, Jon M. Miller, Ehud Behar, Rozenn Boissay-Malaquin, Laura Brenneman, Margaret Buhariwalla, Doyee Byun, Chris Done, Luigi Gallo, Dimitra Gerolymatou, Scott Hagen, Jelle Kaastra, Stephane Paltani, Frederick S. Porter, Richard Mushotzky, Hirofumi Noda, Missagh Mehdipour, Takeo Minezaki, Makoto Tashiro, Abderahmen Zoghbi   +19 more
doaj   +1 more source

The distribution of galactic neighbours of X-ray-selected active galactic nuclei

Monthly Notices of the Royal Astronomical Society
ABSTRACT We combine X-ray data from the X-ray Multi-Mirror Mission 12th data release (4XMM DR12) and the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) Final Equatorial-Depth Survey (eFEDS) early data release catalogues with the Galaxy and Mass Assembly spectroscopic galaxy survey to form a sample of 526 local ($0.05 ...
James R Jones, Michael G Watson, Keir L Birchall, Rhaana L C Starling   +3 more
openaire   +1 more source

In the Eye of the Storm: The Third Giant X-Ray Outburst of the Extreme Changing-look AGN IC 3599

The Astrophysical Journal Letters
We report the discovery and multiwavelength follow-up observations of a giant (factor >100) X-ray outburst of the exceptional changing-look active galactic nucleus (AGN) IC 3599.
D. Grupe, S. Komossa, W. Zheng, A. V. Filippenko, T. G. Brink, N. Schartel, J. Wang, V. Oknyansky, A. V. Dodin, S. Wolsing, E. Elien, C. Tapper, P. Lynam   +12 more
doaj   +1 more source

"Fermi" bubbles are bursting from our galaxy. Their origins remain a mystery. [PDF]

Proc Natl Acad Sci U S A, 2023
Mann A.
europepmc   +1 more source

Redshifted Iron Emission and Absorption Lines in the Chandra X-Ray Spectrum of Centaurus A

The Astrophysical Journal
Cen A hosts the closest active galactic nucleus to the Milky Way, which makes it an ideal target for investigating the dynamical processes in the vicinity of accreting supermassive black holes.
David Bogensberger, Jon Miller, Elias Kammoun, Richard Mushotzky, Laura Brenneman, W. N. Brandt, Edward M. Cackett, Andrew Fabian, Jelle Kaastra, Shashank Dattathri, Ehud Behar, Abderahmen Zoghbi   +11 more
doaj   +1 more source

Strong Amplitude Modulation of Hard-band X-Ray Quasiperiodic Oscillation with Soft-band Flux in RE J1034+396

The Astrophysical Journal
The X-ray quasiperiodic oscillation (QPO) is a remarkable form of variability in systems of compact object accretion. RE J1034+396, harboring the most significant X-ray QPO in active galactic nuclei (AGNs), is the most noteworthy source for in-depth ...
Ruisong Xia, Hao Liu, Yongquan Xue
doaj   +1 more source

First Observational Evidence for an Interconnected Evolution between Time Lag and QPO Frequency among AGNs

The Astrophysical Journal Letters
Quasiperiodic oscillations (QPOs) have been widely observed in black hole X-ray binaries (BHBs), which often exhibit significant X-ray variations. Extensive research has explored the long-term evolution of the properties of QPOs in BHBs.
Ruisong Xia, Hao Liu, Yongquan Xue
doaj   +1 more source

Active galactic nuclei and X-ray observations [PDF]

Journal of Physical Studies, 2016
A. A. Vasylenko, V. I. Zhdanov, E. V. Fedorova   +2 more
openaire   +1 more source