Results 151 to 160 of about 50,208 (269)

Connecting the X-Ray/UV Variability of Fairall 9 with NICER: A Possible Warm Corona

The Astrophysical Journal
The Seyfert 1 active galactic nucleus Fairall 9 was targeted by NICER, Swift, and ground-based observatories for a ∼1000 day long reverberation mapping campaign.
Ethan R. Partington, Edward M. Cackett, Rick Edelson, Keith Horne, Jonathan Gelbord, Erin Kara, Christian Malacaria, Jake A. Miller, James F. Steiner, Andrea Sanna   +9 more
doaj   +1 more source

Hydrogen Column Density Variability in a Sample of Local Compton-thin AGN II

The Astrophysical Journal
We present the multiepoch analysis of 13 variable, nearby ( z ≲ 0.1), and Compton-thin (10 ^22 < N _H < 1.5 × 10 ^24 cm ^−2 ) active galactic nuclei (AGN) selected from the 105-month BAT catalog.
A. Pizzetti, N. Torres-Albà, S. Marchesi, J. Buchner, I. Cox, X. Zhao, S. Neal, D. Sengupta, R. Silver, M. Ajello   +9 more
doaj   +1 more source

Low-Luminosity Accretion in Black Hole X-Ray Binaries and Active Galactic Nuclei [PDF]

, 2005
Ramesh Narayan
openalex   +1 more source

The Variable and Non-variable X-Ray Absorbers in Compton-thin Type II Active Galactic Nuclei [PDF]

, 2020
Sibasish Laha, Alex G. Markowitz, Mirko Krumpe, Robert Nikutta, Richard Rothschild, Tathagata Saha   +5 more
openalex   +1 more source

A Deeper Look into eFEDS AGN Candidates in Dwarf Galaxies with Chandra

The Astrophysical Journal
The ability to accurately discern active massive black holes (BHs) in nearby dwarf galaxies is paramount to understanding the origins and processes of “seed” BHs in the early Universe.
Adonis A. Sanchez, Amy E. Reines, Ákos Bogdán, Ralph P. Kraft   +3 more
doaj   +1 more source

X-ray emission mechanisms in active galactic nuclei

, 2016
Rozenn Boissay-Malaquin
openalex   +2 more sources

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

Multiwavelength Polarization Observations of Mrk 501

The Astrophysical Journal Letters
Mrk 501 is a prototypical high-synchrotron-peaked blazar and serves as one of the primary targets for the Imaging X-ray Polarimetry Explorer (IXPE). In this study, we report X-ray polarization measurements of Mrk 501 based on six IXPE observations.
Xin-Ke Hu, Yu-Wei Yu, Jin Zhang, Xiang-Gao Wang, Kishore C. Patra, Thomas G. Brink, Wei-Kang Zheng, Qi Wang, De-Feng Kong, Liang-Jun Chen, Ji-Wang Zhou, Jia-Xin Cao, Ming-Xuan Lu, Zi-Min Zhou, Yi-Ning Wei, Xin-Bo Huang, Xing-Lin Li, Hao Lou, Ji-Rong Mao, En-Wei Liang, Alexei V. Filippenko   +20 more
doaj   +1 more source

NuSTAR Observation of the TeV-detected Radio Galaxy 3C 264: Core Emission and the Hot Accretion Flow Contribution

The Astrophysical Journal
3C 264 is one of the few FRI radio galaxies with detected TeV emission. It is a low-luminosity active galactic nucleus (LLAGN) and is generally associated with a radiatively inefficient accretion flow (RIAF).
Ka-Wah Wong, Colin M. Steiner, Allison M. Blum, Dacheng Lin, Rodrigo Nemmen, Jimmy A. Irwin, Daniel R. Wik   +6 more
doaj   +1 more source

Optical characteristics of young quasars as sources of the cosmic X-ray background [PDF]

The sources which dominate the thermal cosmic X-ray background cannot have X-ray spectra similar to the power laws measured for bright active galactic nuclei.
Boldt, E., Leiter, D.
core   +1 more source