Results 161 to 170 of about 289,816 (297)
Redshifted Iron Emission and Absorption Lines in the Chandra X-Ray Spectrum of Centaurus A
The Astrophysical JournalCen 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 +11 more
doaj +1 more source
Active galactic nuclei with ultrasoft X-ray emission
The Astrophysical Journal Supplement Series, 1992 The discovery of a class of AGN with clearly distinguishable soft X-ray components below 0.5 keV is reported. These AGN were detected through equivalent hydrogen column densities that are less than a few times 10 exp 20/sq cm. At least three kinds of AGN comprise this sample: low-redshift quasars and Seyfert galaxies that have only ultrasoft emission ...
E. M. Puchnarewicz +5 more
openaire +2 more sources
Signature of a Seyfert-like Component in Blazar 3C 273 and Its Reflection-based Explanation
The Astrophysical JournalWe present the results of blazar 3C 273 from simultaneous observations obtained using the XMM-Newton and NuSTAR satellites during the period 2015–2019 in five epochs. When the spectra are modeled with a power law, significant residuals arise below ∼2 keV
Haritma Gaur +6 more
doaj +1 more source
The nature of the infrared counterpart of IGR J19140+0951
, 2007 The INTEGRAL observatory has been (re-)discovering new X-ray sources since the beginning of nominal operations in early 2003. These sources include X-ray binaries, Active Galactic Nuclei, cataclysmic variables, etc.
Bird +28 more
core +1 more source
Black holes in Active Galactic Nuclei: observations [PDF]
arXiv, 1999 This paper summarizes the observations which provide the best evidence for the presence of black holes in active galactic nuclei. This includes: X-ray variability; kinematical studies using optical emission lines as well as the distribution of megamaser spots; and the shape of the Fe K$\alpha$ X-ray emission line. It also presents the current status of
arxiv
Chandra deep X-ray observation on the Galactic plane
, 2002 Using the Chandra ACIS-I instruments, we have carried out the deepest X-ray observation on a typical Galactic plane region at l 28.5 deg, where no discrete X-ray sources have been known previously.
Bamba, A. +6 more
core +2 more sources
"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
A systematic cross-search for radio/infrared counterparts of XMM-Newton sources
, 2010 We present a catalog of cross-correlated radio, infrared and X-ray sources using a very restrictive selection criteria with an IDL-based code developed by us.
A. Caccianiga +35 more
core +1 more source
X-ray emission mechanisms in active galactic nuclei
, 2016 Active Galactic Nuclei (AGN) are compact regions at the centre of active galaxies which are visible across the full electromagnetic spectrum. Their radiation comes from the accretion of matter onto a supermassive black hole. They are particularly bright in X-rays, showing several components in their spectra.
openaire +3 more sources
The Astrophysical JournalWe present the second NuSTAR and XMM-Newton extragalactic survey of the JWST north ecliptic pole (NEP) time-domain field (TDF). The first NuSTAR NEP-TDF survey had 681 ks total exposure time executed in NuSTAR cycle 5 in 2019 and 2020. This second survey,
Xiurui Zhao +32 more
doaj +1 more source