Soft diffuse X-rays in the southern galactic hemisphere

Abstract

A map is presented of the soft X-ray diffuse background flux in the C band (~ 0.13-0.28 keV) covering almost all of the southern galactic hemisphere. A comparison at constant galactic latitude of both C band and B band (~ 0.1-0.18 keV) soft X-ray data with neutral-hydrogen maps shows that the intensity does decrease with increasing neutral hydrogen column density, N_H, but in a manner that is inconsistent with photoelectric absorption. We suggest that the inverse correlation is a displacement effect. X-ray emission regions appear to be where the cool gas is not. Further, the evidence against photoelectric absorption implies that the bulk of the cool gas is beyond the X-ray emitting regions. Fewer than 10 ²⁰ H atoms cm^-2 can be between the Sun and the X-ray emitting regions. The Sun appears to be surrounded by a soft X-ray emission region of ~ million degree gas.