• DOI:10.1146/annurev.astro.38.1.289
• Corpus ID: 1427929

X-RAY PROPERTIES OF GROUPS OF GALAXIES

@article{Mulchaey2000XRAYPO,
  title={X-RAY PROPERTIES OF GROUPS OF GALAXIES},
  author={John S. Mulchaey},
  journal={Annual Review of Astronomy and Astrophysics},
  year={2000},
  volume={38},
  pages={289-335}
}

• J. Mulchaey
• Published 22 September 2000
• Physics
• Annual Review of Astronomy and Astrophysics

▪ Abstract ROSAT observations indicate that approximately half of all nearby groups of galaxies contain spatially extended X-ray emission. The radial extent of the X-ray emission is typically 50–500 h−1100 kpc or approximately 10–50% of the virial radius of the group. Diffuse X-ray emission is generally restricted to groups that contain at least one early-type galaxy. X-ray spectroscopy suggests the emission mechanism is most likely a combination of thermal bremsstrahlung and line emission. This interpretation requires that the entire volume of groups be filled with a hot, low-density gas known as the intragroup medium. ROSAT and ASCA observations indicate that the temperature of the diffuse gas in groups ranges from approximately 0.3 keV to 2 keV. Higher temperature groups tend to follow the correlations found for rich clusters between X-ray luminosity, temperature, and velocity dispersion. However, groups with temperatures below approximately 1 keV appear to fall off the cluster LX-T relationship (and p...