scholarly journals X-ray emission from warm-hot intergalactic medium: the role of resonantly scattered cosmic X-ray background

2018 ◽  
Vol 482 (4) ◽  
pp. 4972-4984 ◽  
Author(s):  
I Khabibullin ◽  
E Churazov
Keyword(s):  
Intergalactic Medium ◽  
X Ray ◽  
X Ray Background

scholarly journals Heating and Ionization of the Intergalactic Medium by an Early X‐Ray Background

2001 ◽  
Vol 563 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Aparna Venkatesan ◽  
Mark L. Giroux ◽  
J. Michael Shull
Keyword(s):  
Intergalactic Medium ◽  
X Ray ◽  
X Ray Background

scholarly journals The Role of Wide Field X-ray Surveys in Astronomy

2012 ◽  
Vol 10 (H16) ◽  
pp. 669-670
Author(s):  
Richard D. Saxton
Keyword(s):  
High Variability ◽  
Wide Field ◽  
Clusters Of Galaxies ◽  
Tidal Disruption ◽  
X Ray ◽  
Sky Survey ◽  
History Of ◽  
X Ray Background ◽  
Rare Classes

AbstractWe review the history of X-ray sky surveys from the early experiments to the catalogues of 105 sources produced by ROSAT, Chandra and XMM-Newton. At bright fluxes the X-ray sky is shared between stars, accreting binaries and extragalactic sources while deeper surveys are dominated by AGN and clusters of galaxies. The X-ray background, found by the earliest missions, has been largely resolved into discrete sources at soft (0.3-2 keV) energies but at higher energies an important fraction still escapes detection. The possible identification of the missing flux with Compton-thick AGN has been probed in recent years by Swift and Integral.Variability seen in objects observed at different epochs has proved to be an excellent discriminator for rare classes of objects. The comparison of ROSAT All Sky Survey (RASS) and ROSAT pointed observations identified several Novae and high variability AGN as well as initiating the observational study of Tidal Disruption events. More recently the XMM-Newton slew survey, in conjunction with archival RASS data, has detected further examples of flaring objects which have been followed-up in near-real time at other wavelengths.

scholarly journals Diffuse cosmic X-rays from non-thermal intergalactic bremsstrahlung

1970 ◽  
Vol 37 ◽  
pp. 392-401
Author(s):  
Joseph Silk
Keyword(s):  
Cosmic Rays ◽  
Intergalactic Medium ◽  
Energy Requirement ◽  
Cosmic Ray ◽  
X Rays ◽  
Degree Of Ionization ◽  
X Ray ◽  
Normal Galaxies ◽  
X Ray Background ◽  
High Degree

The diffuse X-ray background between 1 keV and 1 MeV is interpreted as non-thermal bremsstrahlung in the intergalactic medium. The observed break in the X-ray spectrum at ∼40 keV yields the heat input to the intergalactic medium, the break being produced by ionization losses of sub-cosmic rays. Proton bremsstrahlung is found not to yield as satisfactory an agreement with observations as electron bremsstrahlung: excessive heating tends to occur. Two alternative models of cosmic ray injection are discussed, one involving continuous injection by evolving sources out to a redshift of about 3, and the other model involving injection by a burst of cosmic rays at a redshift of order 10. The energy density of intergalactic electrons required to produce the observed X-rays is ∼ 10−4 eV/cm3. Assuming a high density (∼ 10−5 cm−3) intergalactic medium, the energy requirement for cosmic ray injection by normal galaxies is ∼ 1058–59ergs/galaxy in sub-cosmic rays. The temperature evolution of the intergalactic medium is discussed, and we find that a similar energy input is also required to explain the observed high degree of ionization (if 3C9 is at a cosmological distance).

scholarly journals The Intergalactic Medium

1982 ◽  
Vol 97 ◽  
pp. 453-459
Author(s):  
A. C. Fabian ◽  
A. K. Kembhavi
Keyword(s):  
Radio Emission ◽  
Intergalactic Medium ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Intergalactic Gas ◽  
X Ray ◽  
Extended Radio ◽  
X Ray Background ◽  
Ngc 1275 ◽  
Intracluster Gas

The density of intergalactic gas may be an important parameter in the formation of extended radio sources. It may range from ∼ 0.1 particle cm−3 in the centres of some rich clusters of galaxies down to 10−8cm−3 or less in intercluster space. The possible influence of the intracluster gas surrounding NGC 1275 on its radio emission is discussed, and the possibility that a significant fraction of the X-ray background is due to a hot intergalactic medium is explored in some detail.

scholarly journals Signs of warm-hot intergalactic medium in the soft X-ray background

2005 ◽  
Vol 436 (1) ◽  
pp. 67-73 ◽  
Author(s):  
A. M. Sołtan ◽  
M. J. Freyberg ◽  
G. Hasinger
Keyword(s):  
Intergalactic Medium ◽  
X Ray ◽  
X Ray Background

scholarly journals IGM Heating and AGN activity in Fossil Galaxy Groups

2013 ◽  
Vol 9 (S304) ◽  
pp. 349-350
Author(s):  
H. Miraghaei ◽  
H. G. Khosroshahi ◽  
H.-R. Klöckner ◽  
T. J. Ponman ◽  
N. N. Jetha ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Intergalactic Medium ◽  
Galactic Nuclei ◽  
Heating Power ◽  
X Ray ◽  
Galaxy Groups ◽  
Recent Group ◽  
Emission Loss

AbstractFossil galaxy groups are energetically and morphologically ideal environments to study the intergalactic medium (IGM) heating, because their inter-galactic gas is undisturbed due to the lack of recent group scale mergers. We study the role of active galactic nuclei (AGN) in heating the IGM in a sample of five fossil galaxy groups by employing properties at 610 MHz and 1.4 GHz. We find that two of the dominant galaxies in fossil groups, ESO 3060170 and RX J1416.4+2315, are associated with the radio lobes. We evaluate the PdV work of the radio lobes and their corresponding heating power and compare to the X-ray emission loss within cooling radius. Our results show that the power due to mechanical heating is not sufficiently high to suppress the cooling.

scholarly journals Compton Heating of the Intergalactic Medium by the Hard X-Ray Background

1999 ◽  
Vol 517 (1) ◽  
pp. L9-L12 ◽  
Author(s):  
Piero Madau ◽  
George Efstathiou
Keyword(s):  
Intergalactic Medium ◽  
X Ray ◽  
X Ray Background
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