2009/03/31 by T. Yoshino, K. Mitsuda, N. Y. Yamasaki +16 · 176 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #Physics #ROSAT #Spectral line #astro-ph.GA #astro-ph.HE
paper · pdf · doi:10.1093/pasj/61.4.805
published in Publications of the Astronomical Society of Japan 61(4), 805-823 (Oxford University Press) · 22 Pages, 8 figures, to appear in PASJ (Vol.61 No.4)
arxiv created 2009/05/13 · openalex publication_date 2009/08/25 · arxiv updated 2015/05/13 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/05
Abstract The soft diffuse X-ray emission of twelve fields observed with Suzaku are presented together with two additional fields from previous analyses. All have galactic longitudes 65^∘ \ltℓ\lt 295^∘ to avoid contributions from the very bright diffuse source that extends at least 30^∘ from the Galactic center. The surface brightnesses of the Suzaku nine fields for which apparently uncontaminated ROSAT All Sky Survey (RASS) were available were statistically consistent with the RASS values, with an upper limit for differences of 17 × 10-6cs-1arcmin-2 in R45-band. The OVII and OVIII intensities are well correlated to each other, and OVII emission shows an intensity floor at ∼2 photonss-1cm-2str-1 (LU). The high-latitude OVIII emission shows a tight correlation with excess of OVII emission above the floor, with (OVIII intensity) = 0.5 × [(OVII intensity) - 2LU], suggesting that temperatures averaged over different line-of-sight show a narrow distribution around ∼0.2 keV. We consider that the offset intensity of OVII arises from the Heliospheric solar wind charge exchange and perhaps from the local hot bubble, and that the excess OVII (2–7LU) is emission from more distant parts of the Galaxy. The total bolometric luminosity of this galactic emission is estimated to be 4 × 1039ergs-1, and its characteristic temperature may be related to the virial temperature of the Galaxy.