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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

References

Bowyer, C.S., Field, G.B., & Mack, J.E. 1968, Nature, 217, 32 Google Scholar
Burrows, D.N. 1989, ApJ, 340, 775 Google Scholar
Burrows, D.N., Kraushaar, W.L., McCammon, D., & Sanders, W.T. 1984, ApJ, 287, 208 Google Scholar
Burrows, D.N., & Mendenhall, J.A. 1991, Nature, 351, 629 Google Scholar
Cox, D.P., & Reynolds, R.J. 1987, ARA&A, 25, 303 Google Scholar
Fernere, K.M. 1995, ApJ, 441, 281 Google Scholar
Frisch, P.C., & York, D.G. 1983, ApJL, 271, L59 Google Scholar
Gry, C., York, D.G., & Vidal-Madjar, A. 1985, ApJ, 296, 593 Google Scholar
Hasinger, G., et al. 1993, A&A, 275, 1 Google Scholar
Hartman, D. & Burton, W.B. 1997, Atlas of Galactic Neutral Hydrogen, (Cambridge University Press:Cambridge)Google Scholar
Jakobsen, P., & Kahn, S.M. 1986, ApJ, 309, 682 Google Scholar
Knapp, G.R. 1975, AJ, 80, 111 Google Scholar
Marshall, F.J., & Clark, G.W. 1984, ApJ, 287, 633 Google Scholar
McKee, C.F., & Ostriker, J.P. 1977, ApJ, 218, 148 Google Scholar
Morrison, R., & McCammon, D. 1983, ApJ, 270, 119 Google Scholar
Raymond, J.C. 1991, private communication, computer code updateGoogle Scholar
Raymond, J.C., & Smith, B.W. 1977, ApJS, 35, 419 Google Scholar
Sanders, W.T., Kraushaar, W.L., Nousek, J.A., & Fried, P.M. 1977, ApJL, 217, L87 Google Scholar
Schlegel, D.J., Finkbeiner, D.P., Davis, M. 1997, in preparationGoogle Scholar
Snowden, S.L., Cox, D.P., McCammon, D., & Sanders, W.T. 1990, ApJ, 354, 211, SCMSGoogle Scholar
Snowden, S.L., Egger, R., Freyberg, M.J., McCammon, D., Plucinsky, P.P., Sanders, W.T., Schmitt, J.H.M.M., Trümper, J., Voges, W., 1997, ApJ, 485, 125 Google Scholar
Snowden, S.L., McCammon, D., Burrows, D.N., & Mendenhall, J.A. 1994, ApJ, 424, 714 Google Scholar
Snowden, S.L., McCammon, D., & Verter, F. 1993, ApJL, 409, L21 Google Scholar
Snowden, S.L., Mebold, U., Hirth, W., Herbstmeier, U., & Schmitt, J.H.M.M. 1991, Science, 252, 1529 Google Scholar
Snowden, S.L., & Pietsch, W. 1995, ApJ, 452, 627 Google Scholar
Snowden, S.L., & Schmitt, J.H.M.M. 1990, Ap&SS, 171, 207 Google Scholar
Trümper, J. 1983, Adv. Space Res., 2(4), 241 Google Scholar
Welsh, B.Y., Craig, N., Vedder, P.W., & Vallerga, J.V. 1994, ApJ, 437, 638 Google Scholar