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 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 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.

Using IRAS Cirrus to Look for X-Ray Shadowing with ROSAT

1990 ◽  
Vol 139 ◽  
pp. 465-466
Author(s):  
Helen J. Walker ◽  
Alan W. Harris ◽  
Timothy J. Sumner
Keyword(s):  
Energy Range ◽  
Wide Field ◽  
Satellite Mission ◽  
X Ray ◽  
Conflicting Evidence ◽  
X Ray Background

The ROSAT X-ray satellite mission and its X-ray telescope (XRT) are described by Trümper (1984). The characteristics of the Wide Field Camera (WFC) on ROSAT and its potential for studies of the soft X-ray background (SXRB) are discussed by Harris, Sumner, and Walker (1989, this volume). The energy range covered by the WFC is 0.06 keV to 0.21 keV (60 Å to 200 Å), whilst the XRT covers the higher energy range from 0.2 keV to 2 keV. Observations performed to date in this field have given rise to conflicting evidence on the location and nature of the 106 K gas, which is presumed to be the origin of the observed emission (see references in Harris, Sumner, and Walker, 1989, this volume).

scholarly journals The X-Ray Background from Star-Forming Galaxies

1990 ◽  
Vol 139 ◽  
pp. 412-413
Author(s):  
Richard E. Griffiths
Keyword(s):  
Energy Range ◽  
Active Galactic Nuclei ◽  
Surface Density ◽  
Galactic Nuclei ◽  
X Ray ◽  
Star Forming ◽  
Smooth Component ◽  
Spatial Fluctuations ◽  
Deep Survey ◽  
X Ray Background

It has been established observationally that at least 30% of the all-sky X-ray background (XRB) in the energy range of 1–3 keV comes from active galactic nuclei (AGN) in the redshift interval of 0.4 to 1.2 (Griffiths et al. 1983, 1988); it is also quite plausible that AGN contribute half of the XRB in the 1–3 keV range (Morisawa and Takahara 1989). However, analysis of spatial fluctuations in the Einstein deep survey counts (Hamilton and Helfand 1987; Barcons and Fabian 1989) has indicated the presence of a relatively smooth component of the XRB with a corresponding surface density of discrete sources of at least several thousand per square degree.

scholarly journals The isotropy of the X-ray background in the energy range 2-18 keV

1980 ◽  
Vol 190 (2) ◽  
pp. 243-260 ◽  
Author(s):  
R. S. Warwick ◽  
J. P. Pye ◽  
A. C. Fabian
Keyword(s):  
Energy Range ◽  
X Ray ◽  
X Ray Background

scholarly journals NuSTAR measurement of the cosmic X-ray background in the 3–20 keV energy band

2021 ◽  
Vol 502 (3) ◽  
pp. 3966-3975
Author(s):  
Roman Krivonos ◽  
Daniel Wik ◽  
Brian Grefenstette ◽  
Kristin Madsen ◽  
Kerstin Perez ◽  
...  
Keyword(s):  
Energy Range ◽  
Energy Band ◽  
Spectral Shape ◽  
Spatial Modulation ◽  
Photon Statistics ◽  
Telescope Array ◽  
X Ray ◽  
Relative Scatter ◽  
X Ray Background ◽  
Systematic Noise

ABSTRACT We present measurements of the intensity of the cosmic X-ray background (CXB) with the Nuclear Spectroscopic Telescope Array (NuSTAR) telescope in the 3–20 keV energy range. Our method uses spatial modulation of the CXB signal on the NuSTAR detectors through the telescope’s side aperture. Based on the NuSTAR observations of selected extragalactic fields with a total exposure of 7 Ms, we have estimated the CXB 3–20 keV flux to be 2.8 × 10−11 erg s−1 cm−2 deg−2, which is $\sim \! 8{{\ \rm per\ cent}}$ higher than that measured with HEAO-1 and consistent with the INTEGRAL measurement. The inferred CXB spectral shape in the 3–20 keV energy band is consistent with the canonical model of Gruber et al. We demonstrate that the spatially modulated CXB signal measured by NuSTAR is not contaminated by systematic noise and is limited by photon statistics. The measured relative scatter of the CXB intensity between different sky directions is compatible with cosmic variance, which opens new possibilities for studying CXB anisotropy over the whole sky with NuSTAR.

scholarly journals Results from ASCA Sky Surveys

1998 ◽  
Vol 179 ◽  
pp. 312-313
Author(s):  
Y. Ogasaka ◽  
Y. Ueda ◽  
Y. Ishisaki ◽  
T. Kii ◽  
T. Takahashi ◽  
...  
Keyword(s):  
Energy Range ◽  
Extensive Study ◽  
X Rays ◽  
Sky Surveys ◽  
X Ray ◽  
Deep Survey ◽  
X Ray Background

The origin of the Cosmic X-ray Background (CXB) radiation has been investigated extensively by soft X-ray deep survey imaging observations with Einstein and ROSAT. In contrast, the lack of telescopes capable of detecting hard X-rays has prevented us from extensive study of the nature of the CXB in the energy range above 2 keV before ASCA.

L X-RAY FLUORESCENCE CROSS-SECTIONS MEASUREMENTS FOR ELEMENTS 56≤Z≤66 IN THE ENERGY RANGE 11-41 keV

1987 ◽  
Vol 48 (C9) ◽  
pp. C8-669-C8-672 ◽  
Author(s):  
S. SINGH ◽  
S. KUMAR ◽  
D. MEHTA ◽  
M. L. GARG ◽  
N. SINGH ◽  
...  
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
X Ray
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