X-Ray Emission in Early-Type Galaxies

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

The Einstein Observatory revealed that elliptical galaxies contained 10(7) K gas with masses in the range of 10(7) - 10(10}M_{sun) . These studies did not yield a complete statistical sample, failed to produce accurate temperatures, and produced few good surface brightness distributions. To alleviate these problems, and to address issues of the origin and heating of the hot gas, we have undertaken a study of a complete optically selected sample of 34 early-type galaxies with ROSAT. First we examine whether there is a contribution to the X-ray emission from stars by comparing the observed X-ray surface brightness distribution to the optical surface brightness distribution. We obtain an upper limit to the stellar contribution of frac {L_{x,stellar}}{L_B}(frac {10(11}Lsun}{10({41}ergs\:s^{-1})) ) <= 0.21 (to the 90% confidence level), indicating that hot gas is the dominant emission mechanism these galaxies. Every galaxy in the sample was detected and has good distances and optical properties. The resulting L_x (0.5-2 keV) to L_B slope is 2.1 +/- 0.4, and with a dispersion about the best fit line that is less than in previous works. Also, there is a correlation between the X-ray gas temperature and the stellar velocity dispersion, as expected for gas in hydrostatic equilibrium. Certain galaxies are X-ray overluminous, probably because they sit in the centers of clusters or groups and have accreted cluster gas in addition to that from galactic stellar mass loss. Other galaxies may be X-ray overluminous due to their interaction with their cluster.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

X-Ray Emission in Early-Type Galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with X-Ray Emission in Early-Type Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and X-Ray Emission in Early-Type Galaxies will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-817998

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.