Non-local origin of a substantial portion of the soft X-ray background

Technical Report · Thu Nov 01 04:00:00 EST 1984

OSTI ID:5925980

Clark, G W

Comparison of the SAS-3 soft X-ray sky survey with the 21-cm neutral hydrogen survey confirms the well-known anticorrelation between the counting rates in the C-band (0.10-0.28 keV) and the column density of neutral hydrogen, and demonstrates that this anticorrelation is significant on all angular scales ranging from that of the general trend from the galactic equator to the poles down to the angular resolution of the detector (2.07 FWHM). Numerous instances of what appear to be soft X-ray shadows of nearly (100-300 pc) 21-cm features, and several bright X-ray regions coincident with holes in the interstellar medium are included in this general correlation. The final set of selected data has an exposure of 2.2 x 10 to the 4th power/sq cm s sr, a sky coverage of 80%, and is free of spurious effects due to charged particles and solar radiations. The validity of the two-component model of the X-ray background, introduced by Davidsen et al. (1977) is examined. In this model the C-band intensity in a given direction is represented as a sum of a constant term, I sub 1, due to unattenuated emission from a local hot bubble in which the solar system is immersed, and a term, I sub 2 exp (N sub H sub th) , due to emission from a diffuse source beyond the neutral hydrogen 2.g., the galactic corona).

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA)
• OSTI ID: 5925980
• Report Number(s): N-85-15567
• Country of Publication: United States
• Language: English

Related Subjects

640103* -- Astrophysics & Cosmology-- Quasi-Stellar
Radio
& X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BACKGROUND RADIATION
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ELECTROMAGNETIC RADIATION
ELEMENTS
EMISSION SPECTRA
GALAXIES
HYDROGEN
INTERSTELLAR SPACE
IONIZING RADIATIONS
MILKY WAY
MONTE CARLO METHOD
NONMETALS
ORIGIN
RADIATIONS
SOFT X RADIATION
SPACE
SPECTRA
SUPERNOVA REMNANTS
X RADIATION