1994年
ASCA OBSERVATION OF 3 BRIGHT EARLY-TYPE GALAXIES - NGC-4472, NGC-4406, AND NGC-4636
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN
- 巻
- 46
- 号
- 3
- 開始ページ
- L65
- 終了ページ
- L70
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- 出版者・発行元
- ASTRONOMICAL SOC JAPAN
We report ASCA 0.3-10 keV X-ray observations of three early type galaxies, NGC 4472, NGC 4406, and NGC 4636. The extended emission in these galaxies is well described by thin thermal emission from hot gas. The gas temperature is 0.92 +/- 0.02 keV for NGC 4472, 0.79 +/- 0.01 keV for NGC 4406, and 0.73 +/- 0.02 keV for NGC 4636. The metal abundance for NGC 4472, NGC 4406, and NGC 4636 are, under the assumption of solar ratios, 0.63 +/- 0.15, 0.45 +/- 0.10, and 0.38 +/- 0.07, respectively. Detailed analysis has allowed determination of the abundances of oxygen, silicon, sulfur, and iron. The observed abundances axe consistent with the solar ratios. For NGC 4472 and NGC 4406 we also determined the mean temperature of the gas producing the Si lines from the ratio of the Si H to He-like lines and find it to be consistent with the continuum temperature. The X-ray temperature is in good agreement with the observed optical velocity dispersion, stellar density profile, and gas density profile. Our data indicates that the supernova rate should be less than one fifth of the nominal rate in early type galaxies. We derive the mass of these systems within fixed angular scales and find that M/L > 40, confirming that elliptical galaxies are dark matter dominated at large radii.
- リンク情報
- ID情報
-
- ISSN : 0004-6264
- Web of Science ID : WOS:A1994NV12400006