Zobrazeno 1 - 10
of 79
pro vyhledávání: '"Abderahmen Zoghbi"'
Autor:
Miranda K. Zak, Jon M. Miller, Ehud Behar, W. N. Brandt, Laura Brenneman, Paul A. Draghis, Elias Kammoun, Michael J. Koss, Mark T. Reynolds, Abderahmen Zoghbi
Publikováno v:
The Astrophysical Journal Letters, Vol 962, Iss 1, p L1 (2024)
Mrk 817 is a bright and variable Seyfert 1.2 active galactic nucleus (AGN). X-ray monitoring of Mrk 817 with the Neil Gehrels Swift Observatory in 2022 revealed that the source flux had declined to a lower level than recorded at any prior point in th
Externí odkaz:
https://doaj.org/article/15187765afc14cdc90bfc8b1c6285819
Autor:
Elias Kammoun, Anne M. Lohfink, Megan Masterson, Dan R. Wilkins, Xiurui Zhao, Mislav Balokovic, Peter G. Boorman, Riley Connors, Paolo Coppi, Andrew Fabian, Javier A. García, Kristin K. Madsen, Nicole Rodriguez Cavero, Navin Sridhar, Daniel Stern, John Tomsick, Thomas Wevers, Dominic J. Walton, Stefano Bianchi, Johannes Buchner, Francesca M. Civano, Giorgio Lanzuisi, Labani Mallick, Giorgio Matt, Andrea Merloni, Emanuele Nardini, Joanna M. Piotrowska, Claudio Ricci, Ka-Wah Wong, Abderahmen Zoghbi
Publikováno v:
Frontiers in Astronomy and Space Sciences, Vol 10 (2024)
The hard X-ray emission in active galactic nuclei (AGN) and black hole X-ray binaries is thought to be produced by a hot cloud of electrons referred to as the corona. This emission, commonly described by a power law with a high-energy cutoff, is sugg
Externí odkaz:
https://doaj.org/article/89d4444f0ddb4266a2823787d2cadb21
Autor:
Paul A. Draghis, Jon M. Miller, Elisa Costantini, Luigi C. Gallo, Mark Reynolds, John A. Tomsick, Abderahmen Zoghbi
Publikováno v:
The Astrophysical Journal, Vol 969, Iss 1, p 40 (2024)
We extend our recent work on black hole spin in X-ray binary systems to include an analysis of 189 archival NuSTAR observations from 24 sources. Using self-consistent data reduction pipelines, spectral models, and statistical techniques, we report an
Externí odkaz:
https://doaj.org/article/9574524d073645968d7498ae9dec1caf
Autor:
Ben Gediman, Jon M. Miller, Abderahmen Zoghbi, Paul Draghis, Zaven Arzoumanian, W. N. Brandt, Keith Gendreau
Publikováno v:
The Astrophysical Journal, Vol 966, Iss 1, p 57 (2024)
We report on a study of the narrow Fe K α line and reflection spectrum in the well-known Seyfert-2 active galactic nucleus (AGN), NGC 4388. X-ray spectra summed from two extensive NICER monitoring campaigns, separated by years, show strong evidence
Externí odkaz:
https://doaj.org/article/b0ce5d790cbb4b18ba3bedefdbc0efd6
Publikováno v:
The Astrophysical Journal, Vol 963, Iss 1, p 38 (2024)
Iron K α (Fe K α ) emission is observed ubiquitously in active galactic nuclei (AGN), and it is a powerful probe of their circumnuclear environment. Examinations of the emission line play a pivotal role in understanding the disk geometry surroundin
Externí odkaz:
https://doaj.org/article/d3c7792929a948d29d053f27aa0e5438
Autor:
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
Publikováno v:
The Astrophysical Journal, Vol 961, Iss 2, p 150 (2024)
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. In this paper, we present 14 Chandra HETGS spectra of th
Externí odkaz:
https://doaj.org/article/63ffca335687435e89b0b857b80b6de7
Autor:
Jon M. Miller, Brenna Mockler, Enrico Ramirez-Ruiz, Paul A. Draghis, Jeremy J. Drake, John Raymond, Mark T. Reynolds, Xin Xiang, Sol Bin Yun, Abderahmen Zoghbi
Publikováno v:
The Astrophysical Journal Letters, Vol 953, Iss 2, p L23 (2023)
The proximity and duration of the tidal disruption event ASASSN-14li led to the discovery of narrow, blueshifted absorption lines in X-rays and UV. The gas seen in X-ray absorption is consistent with bound material close to the apocenter of elliptica
Externí odkaz:
https://doaj.org/article/46ee6f7252734ff498f96835b0f6c982
Publikováno v:
The Astrophysical Journal, Vol 959, Iss 2, p 101 (2023)
The X-ray emission from active galactic nuclei is believed to come from a combination of inverse Compton scattering of photons from the accretion disk and reprocessing of the direct X-ray emission by reflection. We present hard (10–80 keV) and soft
Externí odkaz:
https://doaj.org/article/e392bd2529634ee3b4458ff40c05d301
Publikováno v:
The Astrophysical Journal, Vol 956, Iss 2, p 81 (2023)
The variability of quasar light curves can be used to study the structure of quasar accretion disks. For example, continuum reverberation mapping uses delays between variability in short and long wavelength bands ( short lags) to measure the radial e
Externí odkaz:
https://doaj.org/article/0137c3b51609445081741225efd67845
Autor:
Paul A. Draghis, Jon M. Miller, McKinley C. Brumback, Andrew C. Fabian, John A. Tomsick, Abderahmen Zoghbi
Publikováno v:
The Astrophysical Journal, Vol 954, Iss 1, p 62 (2023)
The black hole (BH) candidate XTE J2012+381 underwent an outburst at the end of 2022. We analyzed 105 NICER observations and two NuSTAR observations of the source during the outburst. The NuSTAR observations of the M ∼ 10 M _⊙ BH indicate clear s
Externí odkaz:
https://doaj.org/article/1c1b68744e774a479615f4901af0d20d