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Date and Time of the Query: 2019-08-24 T01:23:29 PDT
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For refcode 1998ApJ...495L..75B:
Retrieve 34 NED objects in this reference.
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1998ApJ...495L..75B X-Ray Emission from Early-Type Galaxies: A Complete Sample Observed by ROSAT BETH A. BROWN AND JOEL N. BREGMAN Department of Astronomy, University of Michigan, Ann Arbor, MI 48109- 1090; bab@umich.edu, jbregman@umich.edu Received 1997 October 20; accepted 1998 January 4; published 1998 February 24 ABSTRACT To test the cooling flow model of early-type galaxies, we obtained a complete magnitude-limited sample of 34 early-type galaxies, observed with the PSPC and the HRI on ROSAT. The X-ray-to-optical distribution of galaxies implies a lower envelope, which is consistent with the stellar emission inferred from Cen A. When this stellar component is removed, the gaseous emission is related to the optical luminosity by L_X_ is proportional to L_B_^m^, where m = 3.0-3.5, which is significantly steeper than the standard theory (m = 1.7). The dispersion about the correlation is large, with a full range of 30-100 in L_X_ for fixed L_B_. The X-ray temperature is related to the velocity dispersion temperature as T_X_ is proportional to T_{sigma}_^n^, where n = 1.43+/-0.21, although for several galaxies, T_X_ is about twice T_{sigma}_. The excessively hot galaxies are generally the most luminous and are associated with the richest environments. We suggest a model whereby the environment influences the X-ray behavior of these galaxies: early-type galaxies attempt to drive partial or total galactic winds, which can be stifled by the pressure of their environment. Stifled winds should lead to hotter and higher luminosity systems, which would occur most commonly in the richest environments, as observed. Subject headings: galaxies: elliptical and lenticular, cD-galaxies: ISM- X-rays: galaxies
Retrieve 34 NED objects in this reference.
Please click here for ADS abstract

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