Results 111 to 120 of about 9,238,867 (222)
NuSTAR Detection of an Absorption Feature in ESP 39607: Evidence for an Ultrafast Inflow?
The Astrophysical JournalWe report the serendipitous discovery of an absorption feature at 4.8 keV in the NuSTAR spectra of ESP 39607, a Seyfert 2 galaxy at z = 0.201, observed in 2023 May and 2024 August. The feature is detected in both observations with individual significance
Alessandro Peca +6 more
doaj +1 more source
The Astrophysical JournalWe present an enhanced version of the publicly available Stripe 82X catalog (S82-XL), featuring a comprehensive set of 22,737 unique X-ray point sources identified with a significance ≳4 σ .
Alessandro Peca +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 ...
F. A. Cordova +5 more
openaire +1 more source
X-ray and UV emission from active galactic nuclei
, 1984 SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische ...
Truemper, J. (eds.) +2 more
core
Differences of size and shape of active and inactive X-chromosome domains in human amniotic fluid cell nuclei [PDF]
, 1993 It is a widely held belief that the inactive X-chromosome (Xi) in female cell nuclei is strongly condensed as compared to the largely decondensed active X-chromosome (Xa).
Cremer, Thomas +11 more
core +1 more source
The Astrophysical Journal LettersThe high-energy-peaked BL Lacertae objects (HBLs) are the main targets of the Imaging X-ray Polarimetry Explorer (IXPE) for investigating the mechanisms of radiation and particle acceleration in jets. In this Letter, we report the first IXPE observations
Xin-Ke Hu +7 more
doaj +1 more source
A toy model for the X-ray spectral variability of active galactic nuclei
, 2014 Investigations into the long-term X-ray spectral variability of 10 active galactic nuclei (AGNs) revealed a positive spectral index-flux correlation for each object.
Cao, Xinwu, Wang, Jun-Xian
core
X-ray emission from active galactic nuclei [PDF]
, 1985 It is often held that the X-ray emission from active galactic nuclei (AGN) arises from a region close to the central energy source. Thus X-ray observations may provide the best constraints on the central engine.
Mushotzky, R.
core
AGN outflows and the cluster cooling flow conundrum
, 2011 Temperature distributions within cores of galaxy clusters indicate gas in the core should cool down rapidly and contract. The cooling flow problem involves the hypothesis that the rapidly cooling gas should eventually condensate into unobserved molecular
Klees, Ilja
core +1 more source
A Long-term Study of Mrk 50: Appearance and Disappearance of Soft Excess
The Astrophysical JournalWe present an extensive temporal and spectral study of the Seyfert 1 AGN Mrk 50 using 15 yr (2007–2022) of multiwavelength observations from XMM-Newton, Swift, and NuSTAR for the first time.
Narendranath Layek +3 more
doaj +1 more source