scholarly journals Study of the X-Ray Background Spectrum and Its Large-Scale Fluctuation with ASCA

2002 ◽  
Vol 54 (3) ◽  
pp. 327-352 ◽  
Author(s):  
Akihiro Kushino ◽  
Yoshitaka Ishisaki ◽  
Umeyo Morita ◽  
Noriko Y. Yamasaki ◽  
Manabu Ishida ◽  
...  
Keyword(s):  
Large Scale ◽  
Background Spectrum ◽  
X Ray ◽  
Scale Fluctuation ◽  
X Ray Background ◽  
Large Scale Fluctuation

scholarly journals The X-Ray Background

1996 ◽  
Vol 168 ◽  
pp. 245-262
Author(s):  
G. Hasinger
Keyword(s):  
Large Scale ◽  
Recent Progress ◽  
Source Population ◽  
Major Contributor ◽  
Substantial Fraction ◽  
Background Spectrum ◽  
X Ray ◽  
Angular Correlation Function ◽  
X Ray Background

The recent progress in the measurement and understanding of the X-ray background is reviewd here. Particular emphasis is put on a discussion of the partially discrepant measurement of the X-ray background spectrum in the 0.5-3 keV range. New and important constraints on large scale structure are obtained from measurements of the smoothness of the XRB. Recently the first discovery of a signal in the angular correlation function of the XRB could be announced. Finally, various X-ray surveys and their identification content is summarized. The role of optically inactive galaxies as a major contributor to the faint X-ray source population which might produce a substantial fraction of the XRB is clarified.

scholarly journals An additional production mechanism for the diffuse x-ray background

2012 ◽  
Vol 8 (S295) ◽  
pp. 267-267
Author(s):  
Allan D. Ernest ◽  
Matthew P. Collins ◽  
Graeme L. White
Keyword(s):  
Large Scale ◽  
Quantum States ◽  
Production Mechanism ◽  
X Ray ◽  
Additional Production ◽  
X Ray Background

AbstractWe propose a mechanism that contributes energy and particles to the diffuse x-ray halos of galaxies and clusters, based on the dark quantum states of large-scale gravity wells.

scholarly journals 9.18. Galactic winds in active galaxies

1998 ◽  
Vol 184 ◽  
pp. 417-418 ◽  
Author(s):  
S. Veilleux ◽  
J. Bland-Hawthorn ◽  
G. Cecil ◽  
P. Shopbell
Keyword(s):  
Absorption Line ◽  
Galaxy Formation ◽  
Large Scale ◽  
Large Scale Structure ◽  
Active Galaxies ◽  
Large Scale Circulation ◽  
X Ray ◽  
Hubble Sequence ◽  
Galactic Winds ◽  
X Ray Background

The effects of large-scale galactic winds in active galaxies may be far-reaching. It has been suggested that the Hubble sequence can be understood in terms of a galaxy's greater ability to sustain winds with increasing bulge-to-disk ratio. The large-scale circulation of gas associated with these galactic winds might help explain the mass-metallicity relation between galaxies and the metallicity-radius relation within galaxies. Galactic winds probably contribute non-negligibly to the cosmic X-ray background and may be involved in the quasar absorption-line phenomenon. The cosmological implications of the wind phenomenon have been widely explored in the context of proto-galaxies and quasars. The extremely energetic galactic winds that were likely associated with galaxy formation almost certainly played a key role in heating and ionizing the intergalactic medium at high redshifts and may have created the seeds for the large-scale structure we see today.

The 20keV Break in the Diffuse X-ray Background Spectrum

1977 ◽  
Vol 3 (2) ◽  
pp. 131-132
Author(s):  
R. M. Hudson ◽  
R. M. Thomas ◽  
M. L. Duldig
Keyword(s):  
Spectral Index ◽  
Simple Analysis ◽  
Background Spectrum ◽  
X Ray ◽  
Independent Determination ◽  
Analysis Technique ◽  
X Ray Background

In this paper we report an independent determination of the Location of the break (change in spectral index) in the spectrum of the diffuse X-ray background by applying a simple analysis technique to data already in the literature.

scholarly journals The Microwave Background Radiation

1990 ◽  
Vol 139 ◽  
pp. 333-343 ◽  
Author(s):  
G. De Zotti ◽  
L. Danese ◽  
L. Toffolatti ◽  
A. Franceschini
Keyword(s):  
Large Scale ◽  
Background Radiation ◽  
High Redshift ◽  
Dust Emission ◽  
Radio Sources ◽  
Microwave Background ◽  
Satisfactory Explanation ◽  
X Ray ◽  
Microwave Background Radiation ◽  
X Ray Background

We review the data on the spectrum and isotropy of the microwave background radiation and the astrophysical processes that may produce spectral distortions and anisotropies. As yet no fully satisfactory explanation has been found for the submillimeter excess observed by Matsumoto et al. (1988). The most precise data at λ > 1 mm disagree with nonrelativistic comptonization models which match the excess. Distortions produced by a very hot intergalactic medium yielding the X-ray background do not fit the submillimeter data. Very special requirements must be met for the interpretation in terms of high-redshift dust emission to work.Reported anisotropies on scales of several degrees and of tens of arcsec may be produced, at least in part, by discrete sources. Because the best experiments at cm wavelengths are close to the confusion limit, they provide interesting information on the large-scale distribution of radio sources.

scholarly journals The Soft X-ray Background Spectrum from DXS

1997 ◽  
Vol 166 ◽  
pp. 83-90 ◽  
Author(s):  
W.T. Sanders ◽  
R.J. Edgar ◽  
D.A. Liedahl ◽  
J.P. Morgenthaler
Keyword(s):  
Galactic Plane ◽  
Emission Lines ◽  
Background Spectrum ◽  
Local Bubble ◽  
X Ray ◽  
Hot Plasma ◽  
Solar Abundances ◽  
Ionic Emission ◽  
X Ray Background ◽  
Ionization Balance

AbstractThe Diffuse X-ray Spectrometer (DXS) obtained spectra of the low energy X-ray (44 – 83 Å) diffuse background near the galactic plane from galactic longitudes 150° ≲ l ≲ 300° with ≲ 3 Å spectral resolution and ~ 15° angular resolution. Thus, DXS measured X-ray spectra that arise almost entirely from within the Local Bubble. The DXS spectra show emission lines and emission-line blends, indicating that the source of the X-ray emission is thermal – hot plasma in the Local Bubble. The measured spectra are not consistent with those predicted by standard coronal models, either with solar abundances or depleted abundances, over the temperature range 105 – 107 K. The measured spectra are also inconsistent with the predictions of various non-equilibrium models. A nearly acceptable fit to DXS spectra can be achieved using a hybrid model that combines the Raymond & Smith ionization balance calculation with recently calculated (by DAL) ionic emission lines.

Spectra and large-scale isotropy of the cosmic X-ray background from ASCA observations

1998 ◽  
Vol 319 (1-2) ◽  
pp. 68-68 ◽  
Author(s):  
Y. Ishisaki ◽  
Y. Ueda ◽  
T. Takahashi ◽  
H. Inoue ◽  
Y. Ogasaka ◽  
...  
Keyword(s):  
Large Scale ◽  
X Ray ◽  
X Ray Background
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