The spatial distribution and spectral characteristics of the diffuse soft X-ray background

Singh, K. P. ; Agrawal, P. C. ; Manchanda, R. K. ; Naranan, S. ; Sreekantan, B. V. (1983) The spatial distribution and spectral characteristics of the diffuse soft X-ray background Astronomy & Astrophysics, 117 (2). pp. 319-331. ISSN 0004-6361

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The diffuse emission in soft X-rays (0.1-2.5 keV) was measured over half the sky with 5° (FWHM) spatial resolution during a sky survey experiment. X-ray intensity maps in galactic coordinates are presented in B(0.1-0.19 keV), L(0.1-0.28KeV), and M(0.4-0.9 keV) energy bands. The maps contain observations from part of the sky bounded by galactic longitudes l=180° to 270° and galactic latitudes b=40° to 80°, which is poorly studied in other surveys. Regions of excess soft X-ray emission are found to be associated with an edge of Loop I and its extension in the Southern galactic hemisphere, the northern HI hole and other features in HI and radio continuum surveys. No quantitative correlation is observed between the X-ray intensity and natural hydrogen column density (NH). The energy spectra observed from some regions otside the Loop I are best fitted with thermal emission spectra of a hot plasma with cosmic elemental abundances, negligible interstellar absorption and temperature 106.2-106.3K. The observed emission measures over several regions of sky are in the range of (0.27-1.0) 10−2 cm−6 pc. Present data support the local origin for the soft X-ray background from a thermal plasma of presure ≳4600 cm−3 K, temperature ~106 K and size ≲330 pc. A spread in the temperature of the local hot plasma with cosmic elemental abundances, is necessary to explain the observed variation in the hardness ratio.

Item Type:Article
Source:Copyright of this article belongs to EDP Sciences.
Keywords:Soft X-ray Background; Hot Interstellar Medium; X-ray Spectra
ID Code:59046
Deposited On:03 Sep 2011 12:07
Last Modified:18 May 2016 09:45

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