The dark matter halo structure of "fossil" groups candidates

T. Yoshioka, A. Furuzawa, S. Takahashi, Y. Tawara, S. Sato, K. Yamashita, Y. Kumai

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

We investigated properties of four isolated giant elliptical galaxies with extended X-ray halo using ASCA data, The derived size of X-ray halo, X-ray luminosity, and gravitational mass of the dark halo are unusually large those of X-ray halo of a single galaxy, but are typical for X-ray halos of groups and poor clusters of galaxies. The measured temperatures and abundances of the X-ray halo gas in these galaxies are also similar to those of the groups and poor clusters. Based on these results we identified these galaxies as "isolated X-ray overluminous elliptical galaxy" (IOLEG). The radial profiles of dark halo in these objects were derived from X-ray data. It is found that some are similar to those of compact groups while others are the same as those of normal ellipticals. The dark halos of lOLEGs are thus indistinguishable from those of groups (and poor clusters), which appears to be consistent with a widely believed idea that lOLEGs are a product of dynamical evolution of a compact group. However, mass-to-light ratios of IOLEGs (M 200 /L B ∼ 100-1000) are far greater than those of Hickson compact groups M 200 /J B ∼ 40-60). Since it is hard to consider that total optical luminosity of a compact group decreases by an order of magnitude in the course of dynamical evolution, such difference in the observed mass-to-light ratio between IOLEGs and Hickson compact groups strongly suggests that most IOLEGs have not evolved from compact groups which are observed at present.

Original languageEnglish
Pages (from-to)2525-2529
Number of pages5
JournalAdvances in Space Research
Volume34
Issue number12 SPEC.ISS.
DOIs
Publication statusPublished - 01-01-2004

Fingerprint

fossils
Galaxies
halos
dark matter
fossil
X rays
x rays
galaxies
mass to light ratios
elliptical galaxies
Luminance
luminosity
Gases
gas
products
profiles
gases

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering
  • Astronomy and Astrophysics
  • Geophysics
  • Atmospheric Science
  • Space and Planetary Science
  • Earth and Planetary Sciences(all)

Cite this

Yoshioka, T., Furuzawa, A., Takahashi, S., Tawara, Y., Sato, S., Yamashita, K., & Kumai, Y. (2004). The dark matter halo structure of "fossil" groups candidates. Advances in Space Research, 34(12 SPEC.ISS.), 2525-2529. https://doi.org/10.1016/j.asr.2003.03.076
Yoshioka, T. ; Furuzawa, A. ; Takahashi, S. ; Tawara, Y. ; Sato, S. ; Yamashita, K. ; Kumai, Y. / The dark matter halo structure of "fossil" groups candidates. In: Advances in Space Research. 2004 ; Vol. 34, No. 12 SPEC.ISS. pp. 2525-2529.
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Yoshioka, T, Furuzawa, A, Takahashi, S, Tawara, Y, Sato, S, Yamashita, K & Kumai, Y 2004, 'The dark matter halo structure of "fossil" groups candidates', Advances in Space Research, vol. 34, no. 12 SPEC.ISS., pp. 2525-2529. https://doi.org/10.1016/j.asr.2003.03.076

The dark matter halo structure of "fossil" groups candidates. / Yoshioka, T.; Furuzawa, A.; Takahashi, S.; Tawara, Y.; Sato, S.; Yamashita, K.; Kumai, Y.

In: Advances in Space Research, Vol. 34, No. 12 SPEC.ISS., 01.01.2004, p. 2525-2529.

Research output: Contribution to journalArticle

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Yoshioka T, Furuzawa A, Takahashi S, Tawara Y, Sato S, Yamashita K et al. The dark matter halo structure of "fossil" groups candidates. Advances in Space Research. 2004 Jan 1;34(12 SPEC.ISS.):2525-2529. https://doi.org/10.1016/j.asr.2003.03.076