The diffuse cosmic X-ray background spectrum in the 2–10 keV energy range

1973 ◽  
Vol 24 (2) ◽  
pp. 585-592 ◽  
Author(s):  
D. J. Adams ◽  
M. J. Ricketts
Keyword(s):  
Energy Range ◽  
Background Spectrum ◽  
X Ray ◽  
X Ray Background

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 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.

scholarly journals Evidence for a galactic component of the diffuse X-ray background

1970 ◽  
Vol 37 ◽  
pp. 280-288
Author(s):  
B. A. Cooke ◽  
R. E. Griffiths ◽  
K. A. Pounds
Keyword(s):  
Energy Range ◽  
Low Energy ◽  
Galactic Latitude ◽  
X Ray ◽  
Latitude Dependence ◽  
The Galaxy ◽  
X Ray Background

It is widely believed that the diffuse X-ray background, observed on several occasions over the energy range from 0.25 keV to above 1 MeV has an extragalactic origin. Evidence for this comes from the generally reported isotropy above several keV [1, 2, 3] and the observed galactic latitude dependence at 0.25 keV, believed to result from the interstellar attenuation of these low energy photons in passage through the Galaxy [4, 5].

scholarly journals The Shape of Soft X-ray Spectra of Quasars

1989 ◽  
Vol 134 ◽  
pp. 175-176
Author(s):  
D. A. Schwartz ◽  
Y. Qian ◽  
W. H. Tucker
Keyword(s):  
Flux Density ◽  
Power Laws ◽  
Seyfert Galaxies ◽  
Background Spectrum ◽  
X Ray ◽  
The Mean ◽  
X Ray Background ◽  
Image Position ◽  
Two Parameters ◽  
Lines Of Evidence

Several lines of evidence suggest that the x-ray spectra of quasars are not simple, exact power laws: 1. when Wilkes and Elvis (1987) analyzed quasars as power laws they found an absorption less than that due to our galaxy; 2. The mean 0.3 to 3.5 keV spectral index is steeper than the mean for the 2 to 20 keV range; 3. although several lines of evidence argue that AGN provide a significant portion (perhaps all) of the x-ray background, the diffuse background spectrum does not agree with the x-ray power-law indices measured for quasars or Seyfert galaxies. Schwartz and Tucker (1988) have suggested that all the above conflicts are reconciled if the slope in the Log(flux density) vs. Log(energy) plot flattens continuously with increasing energy. In this paper we utilize one particular parameterization suggested for the flux density, which we call the “log-slope” model: where f is the flux density, K a normalization parameter which is not of interest here, and a and b are the two parameters of our fit.

scholarly journals ASCA Sky Survey Observations and the Cosmic X-Ray Background in 2-10 KeV

1998 ◽  
Vol 188 ◽  
pp. 197-200
Author(s):  
H. Inoue ◽  
T. Takahashi ◽  
Y. Ueda ◽  
A. Yamashita ◽  
Y. Ishisaki ◽  
...  
Keyword(s):  
Energy Range ◽  
Galactic Plane ◽  
Galactic Latitude ◽  
High Galactic Latitude ◽  
X Ray ◽  
Sky Survey ◽  
X Ray Background ◽  
Excess Component ◽  
Highly Uniform

The X-ray background in the energy range above 2 keV is highly uniform except for an excess component along the Galactic plane. The excess along the plane is considered to be associated with our Galaxy, whereas the rest of the emission is believed to be of extragalactic origin. In this paper, the X-ray background at high Galactic latitude is discussed and is designated as the CXB (cosmic X-ray background) to distinguish it from the Galactic origin.

Diffuse X-ray background measurements in the energy range 2?18 keV

1971 ◽  
Vol 10 (1) ◽  
pp. 150-155 ◽  
Author(s):  
A. S. Prakasarao ◽  
D. P. Sharma ◽  
U. B. Jayanthi ◽  
U. R. Rao
Keyword(s):  
Energy Range ◽  
X Ray ◽  
X Ray Background

scholarly journals The diffuse X-ray background spectrum from 3 to 50 keV

1980 ◽  
Vol 235 ◽  
pp. 4 ◽  
Author(s):  
F. E. Marshall ◽  
E. A. Boldt ◽  
S. S. Holt ◽  
R. B. Miller ◽  
R. F. Mushotzky ◽  
...  
Keyword(s):  
Background Spectrum ◽  
X Ray ◽  
X Ray Background
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