Suzaku view of soft X-ray diffuse background in 0.4 - 1 keV .
Abstract
The origins of the soft diffuse X-ray background are discussed basing on recent Suzaku observations. The O VII and O VIII intensities of fourteen different fields were determined with Suzaku with relatively small statistical and systematic errors. The O VII and O VIII intensities show strong correlations: O VII emission shows an intensity floor at ∼ 2 photons s-1 cm-2 str-1 (LU), while the high-latitude O VIII emission shows a tight correlation with excess of O VII emission above the floor, with (O VIII intensity) = 0.5 × [(O VII intensity) - 2 LU], suggesting that temperatures averaged over different line-of-sight show a narrow distribution around ∼ 0.2 keV. We consider that the offset intensity of O VII arises from the Heliospheric solar wind charge exchange, and that the excess O VII (2-7 LU) is emission from more distant parts of the Galaxy, which may be regarded as the halo of our Galaxy. The total bolometric luminosity of this galactic emission is estimated to be 4 × 1039 erg s-1, and its characteristic temperature may be related to the virial temperature of the Galaxy.
- Publication:
-
Memorie della Societa Astronomica Italiana
- Pub Date:
- 2010
- Bibcode:
- 2010MmSAI..81...69M
- Keywords:
-
- Galaxy: disk;
- Galaxy: halo;
- X-rays: diffuse background;
- X-rays: ISM