Zobrazeno 1 - 10
of 245
pro vyhledávání: '"Ehud Behar"'
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:
Sharon Mitrani, Ehud Behar, Jeremy J. Drake, Marina Orio, Kim Page, Valentina Canton, Jan-Uwe Ness, Kirill Sokolovsky
Publikováno v:
The Astrophysical Journal, Vol 970, Iss 1, p 54 (2024)
The origin of bright X-ray emission lines that appear late in a nova eruption remains largely a puzzle. We present two high-resolution X-ray grating spectra of the classical nova YZ Ret, observed 77 and 115 days post-eruption, using XMM-Newton and Ch
Externí odkaz:
https://doaj.org/article/581d7e10aad3493faceab2604f6b578c
Autor:
Keigo Fukumura, Missagh Mehdipour, Ehud Behar, Chris Shrader, Mauro Dadina, Demosthenes Kazanas, Stefano Marchesi, Francesco Tombesi
Publikováno v:
The Astrophysical Journal, Vol 968, Iss 2, p 70 (2024)
X-ray obscuration of active galactic nuclei (AGNs) is considered in the context of ionized winds of stratified structure launched from accretion disks. We argue that a Compton-thick layer of a large-scale disk wind can obscure continuum X-rays and al
Externí odkaz:
https://doaj.org/article/3c7689ffba374144888d5d2d687e361a
Publikováno v:
The Astrophysical Journal, Vol 966, Iss 2, p 211 (2024)
Supernovae are responsible for the elemental enrichment of the galaxy, and some are postulated to leave behind a black hole. In a stellar binary system, the supernova pollutes its companion, and the black hole can accrete back its own debris and emit
Externí odkaz:
https://doaj.org/article/69dbf67550564454bc91a9973cb5d36a
Autor:
Sina Chen, Preeti Kharb, Silpa Sasikumar, Sumana Nandi, Marco Berton, Emilia Järvelä, Ari Laor, Ehud Behar, Luigi Foschini, Amelia Vietri, Minfeng Gu, Giovanni La Mura, Luca Crepaldi, Minhua Zhou
Publikováno v:
The Astrophysical Journal, Vol 963, Iss 1, p 32 (2024)
We present new 1.5–8.5 GHz Very Long Baseline Array (VLBA) observations and 0.32–1.26 GHz Giant Meterwave Radio Telescope (GMRT) observations of J0354−1340, which is the only known radio-quiet (RQ) or radio-intermediate (RI) narrow-line Seyfert
Externí odkaz:
https://doaj.org/article/8f84c7ce88df40579ac8829bbb60bcb7
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:
Sharon Mitrani, Ehud Behar
Publikováno v:
The Astrophysical Journal, Vol 957, Iss 2, p 105 (2023)
The population of metastable levels is key to high-precision density diagnostics of astrophysical plasmas. In photoionized plasmas, density is used to infer the distance from the ionizing source, which is otherwise difficult to obtain. Perfecting mod
Externí odkaz:
https://doaj.org/article/9957c2b6507a4a639914023bc39926a2
Autor:
Eran Vax, Nadav Ben David, Yossi Salomon, Yakir Knafo, Shay Dadon, Adrian Stern, Ehud Behar, Alon Osovizky
Publikováno v:
EPJ Web of Conferences, Vol 288, p 10023 (2023)
Mutual-Shielding Directional Gamma Detector excels at sensitivity and can achieve good angular accuracy and a large field of view. In this paper, we present, in detail, a method to optimize a mutual shielding directional detector array regarding the
Externí odkaz:
https://doaj.org/article/e57bbf1e22a8419b8bc7cfbabca8d8c0
Autor:
Ritesh Ghosh, Sibasish Laha, Eileen Meyer, Agniva Roychowdhury, Xiaolong Yang, J. A. Acosta–Pulido, Suvendu Rakshit, Shivangi Pandey, Josefa Becerra González, Ehud Behar, Luigi C. Gallo, Francesca Panessa, Stefano Bianchi, Fabio La Franca, Nicolas Scepi, Mitchell C. Begelman, Anna Lia Longinotti, Elisabeta Lusso, Samantha Oates, Matt Nicholl, S. Bradley Cenko, Brendan O’Connor, Erica Hammerstein, Jincen Jose, Krisztina Éva Gabányi, Federica Ricci, Sabyasachi Chattopadhyay
Publikováno v:
The Astrophysical Journal, Vol 955, Iss 1, p 3 (2023)
1ES1927+654 is a nearby active galactic nucleus (AGN) that has shown an enigmatic outburst in optical/UV followed by X-rays, exhibiting strange variability patterns at timescales of months to years. Here we report the unusual X-ray, UV, and radio var
Externí odkaz:
https://doaj.org/article/5b65bd53fd5d44ceb00411723b0d225d
Autor:
Matan Grauer, Ehud Behar
Publikováno v:
The Astrophysical Journal, Vol 953, Iss 2, p 158 (2023)
A large fraction of the baryons at low redshift are undetected and likely reside in the tenuous, hot intergalactic medium (IGM). One way to probe the missing baryons is through their absorption of bright sources. The anomalous absorption excess in th
Externí odkaz:
https://doaj.org/article/0a3c107f77874ca5b0e9665596bc02f9