Line Emission in the X-Ray Background

1971 ◽  
Vol 166 ◽  
pp. L9 ◽  
Author(s):  
Seth Shulman ◽  
Gilbert Fritz ◽  
John F. Meekins ◽  
T. A. Chubb ◽  
H. Friedman ◽  
...  
Keyword(s):  
Line Emission ◽  
X Ray ◽  
X Ray Background

scholarly journals A Limit on Line Emission in the X-Ray Background at High Galactic Latitudes

1971 ◽  
Vol 167 ◽  
pp. L1 ◽  
Author(s):  
E. A. Boldt ◽  
U. D. Desai ◽  
S. S. Holt ◽  
P. J. Serlemitsos
Keyword(s):  
Line Emission ◽  
X Ray ◽  
On Line ◽  
X Ray Background

scholarly journals Features in the Soft X-ray Background

1990 ◽  
Vol 115 ◽  
pp. 146-155
Author(s):  
R. Rothenflug
Keyword(s):  
Energy Resolution ◽  
Line Emission ◽  
Spatial Variations ◽  
Emission Lines ◽  
X Ray ◽  
Hot Gas ◽  
The North ◽  
North Polar ◽  
X Ray Background ◽  
Japanese Group

AbstractThe soft X-ray background is explained in terms of emission coming from hot gas. Most of these soft X-ray data were obtained by proportional counters with a poor energy resolution. Instruments having the capability to resolve lines were only flown by two groups: a GSPC by a Japanese group and a SSD by a french-american collaboration. They both detected the 0 VII line emission coming from the soft X-ray background and so proved the thermal nature of the emission. The implications of these results on possible models for the local hot medium will be discussed. The same detectors observed part of the North Polar Spur. They detected emission lines coming from different species (0 VII,Fe XVII,Ne IX). Spatial variations of line ratios for this object could be due to non-equilibrium ionization effects.

Limit on Line Emission in the Diffuse X-Ray Background.

1972 ◽  
Vol 172 ◽  
pp. L73 ◽  
Author(s):  
A. Toor ◽  
R. E. Price ◽  
F. D. Seward
Keyword(s):  
Line Emission ◽  
X Ray ◽  
On Line ◽  
X Ray Background

scholarly journals Fe VIII, IX, and X Line Emission From the Soft X-ray Background: Previous Limits and a Future Measurement

1990 ◽  
Vol 115 ◽  
pp. 160-163
Author(s):  
J. J. Bloch ◽  
W. C. Priedhorsky ◽  
Barham W. Smith
Keyword(s):  
Broad Band ◽  
Pulse Height ◽  
Line Emission ◽  
Elemental Abundance ◽  
Cluster Emission ◽  
X Ray ◽  
Pulse Height Analysis ◽  
Emission Models ◽  
X Ray Background ◽  
Imaging Sensors

AbstractWe discuss pulse height analysis of Be band data in relation to the important 72 eV Fe line cluster emission from the soft X-ray background (SXRB). Pulse height fits to the Be band data suggest that the Fe lines must be suppressed by a factor of ~10 with respect to the rest of the X-ray spectrum. The broad band rates and the mean energy of the pulse height data for the Be band can be brought into agreement by using depleted elemental abundance emission models. A planned measurement of the SXRB Fe lines using the Array of Low Energy X-ray Imaging Sensors (ALEXIS) experiment could resolve this issue.

scholarly journals OVII and OVIII line emission in the diffuse soft X-ray background: heliospheric and galactic contributions

2007 ◽  
Vol 475 (3) ◽  
pp. 901-914 ◽  
Author(s):  
D. Koutroumpa ◽  
F. Acero ◽  
R. Lallement ◽  
J. Ballet ◽  
V. Kharchenko
Keyword(s):  
Line Emission ◽  
X Ray ◽  
X Ray Background

scholarly journals EBIT charge-exchange measurements and astrophysical applications

2008 ◽  
Vol 86 (1) ◽  
pp. 151-169 ◽  
Author(s):  
B J Wargelin ◽  
P Beiersdorfer ◽  
G V Brown
Keyword(s):  
Charge Exchange ◽  
Supernova Remnants ◽  
Galactic Center ◽  
Line Emission ◽  
Laboratory Measurements ◽  
X Ray ◽  
The Past ◽  
Theoretical Predictions ◽  
X Ray Background ◽  
Key Aspects

The past decade has seen a surge of interest in astrophysical charge exchange (CX). The impetus was the discovery of X-ray emission from comets in 1996, soon followed by the observation of CX emission in planetary atmospheres and throughout the heliosphere. Geocoronal and heliospheric CX are now recognized as contributing a considerable fraction of the soft X-ray background, and stellar-wind charge exchange is expected to occur in the astrospheres surrounding many stars. CX may also contribute to X-ray line emission in supernova remnants, the Galactic Center, and the Galactic Ridge. This article summarizes the key aspects of CX X-ray emission and its astrophysical relevance, and reviews related laboratory measurements and theoretical predictions with particular attention to spectroscopy experiments conducted on electron beam ion traps.PACS Nos.: 32.30.Rj, 34.70.+e, 39.10.+j, 95.30.Dr

Iron K-Line Emission from X-Ray Binaries

1988 ◽  
Vol 102 ◽  
pp. 47-50
Author(s):  
K. Masai ◽  
S. Hayakawa ◽  
F. Nagase
Keyword(s):  
Accretion Disk ◽  
Radiative Recombination ◽  
Characteristic Temperature ◽  
Line Emission ◽  
Ionization Front ◽  
Continuum Radiation ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx> 10 keV is likely due to fluorescence outside the He II ionization front.

scholarly journals Silicon in the solar corona

1965 ◽  
Vol 23 ◽  
pp. 115-123
Author(s):  
K. G. Widing ◽  
J. R. Porter
Keyword(s):  
Solar Corona ◽  
Relative Intensity ◽  
Line Emission ◽  
X Ray ◽  
Resonance Transitions ◽  
Spectral Ranges

Resonance lines of coronal ions of silicon are prominent in the spectral ranges 40–62 Å and 254–356 Å.An unexpected feature of the soft X-ray spectrum is the weakness or absence of the resonance lines of iron in ionization stages XI through XV.A second feature is the prominence of lines of the type (3d → 2p) relative to the resonance transitions (3p → 2s) in Li-like and Beryllium-like spectra. It is suggested that the upper levels (3d) are excited by quadrupole collisions from the ground 2s or 2s2levels.The intensity of the soft X-ray lines relative to the resonance lines in the 300 Å region seems to be more consistent with temperatures well above one million degrees than with temperatures as low as 700000°K, but the data are not adequate for a precise comparison. The relative intensity of the line emission from the various stages of silicon ionization may be interpreted as indicating that the ionization of silicon peaks in stages IX and X.The abundances of C, Mg, S, and Al relative to silicon do not seem to be greatly different from the chromospheric abundances reported by Pottasch or with the photospheric abundances.

scholarly journals X-ray Properties of 3C 111: Separation of Primary Nuclear Emission and Jet Continuum

Universe ◽  
2020 ◽  
Vol 6 (11) ◽  
pp. 219
Author(s):  
Elena Fedorova ◽  
B.I. Hnatyk ◽  
V.I. Zhdanov ◽  
A. Del Popolo
Keyword(s):  
Accretion Disk ◽  
Power Law ◽  
Line Emission ◽  
High Energy ◽  
Power Law Model ◽  
X Ray ◽  
Additional Information ◽  
Observational Dataset ◽  
Simple Power ◽  
Photon Index

3C111 is BLRG with signatures of both FSRQ and Sy1 in X-ray spectrum. The significant X-ray observational dataset was collected for it by INTEGRAL, XMM-Newton, SWIFT, Suzaku and others. The overall X-ray spectrum of 3C 111 shows signs of a peculiarity with the large value of the high-energy cut-off typical rather for RQ AGN, probably due to the jet contamination. Separating the jet counterpart in the X-ray spectrum of 3C 111 from the primary nuclear counterpart can answer the question is this nucleus truly peculiar or this is a fake “peculiarity” due to a significant jet contribution. In view of this question, our aim is to estimate separately the accretion disk/corona and non-thermal jet emission in the 3C 111 X-ray spectra within different observational periods. To separate the disk/corona and jet contributions in total continuum, we use the idea that radio and X-ray spectra of jet emission can be described by a simple power-law model with the same photon index. This additional information allows us to derive rather accurate values of these contributions. In order to test these results, we also consider relations between the nuclear continuum and the line emission.

scholarly journals The unified Seyfert scheme and the origin of the cosmic X-ray background

1994 ◽  
Vol 270 (1) ◽  
pp. L17-L21 ◽  
Author(s):  
P. Madau ◽  
G. Ghisellini ◽  
A. C. Fabian
Keyword(s):  
X Ray ◽  
X Ray Background
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