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A New View of the LHB and ¼ keV X-ray Halo

Published online by Cambridge University Press:  12 April 2016

S.L. Snowden
S.L. Snowden*
Affiliation:
NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771, USA

Abstract

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The X-ray sky at ¼ keV is completely dominated by diffuse emission. It has become clear that it originates as at least three separate components: local emission within the nearest ~ 100 pc from the Sun, halo emission from beyond most of the neutral material of the Galactic disk, and the superposition of unresolved extragalactic sources. The only way to determine the temperatures and relative emission measures of the hot plasma responsible for the Galactic components is to use the X-ray intensity variations due to column density variations in the intervening Hi to separate the components. “Shadowing” studies have been pursued for individual objects using ROSAT data, from both pointed observations and the all-sky survey with considerable success.

This paper presents the results of an all-sky analysis of the ¼ keV background from the ROSAT survey. A Local Hot Bubble is found consistent with, although somewhat smaller than, previous models. It has a temperature of 106.1 K and an emission measure which varies by a factor of ~ 3.3 over large angles. The halo emission has a temperature near 106.0 K with an emission measure which varies from near zero to more than five times that of the local emission.

Type
Part III Observations and Modeling of the Local Bubble and the SXRB
Information
International Astronomical Union Colloquium , Volume 166: The Local Bubble and Beyond , 1997 , pp. 103 - 112
Copyright
Copyright © Springer-Verlag 1998

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