| 翻訳と辞書 |
| Holmberg 15A ： ウィキペディア英語版 |
Holmberg 15A
Holmberg 15A is a supergiant elliptical galaxy and the central dominant galaxy of the Abell 85 galaxy cluster in the constellation Cetus, about 700 million light-years from Earth. It was discovered c. 1937 by Erik Holmberg. It is notable for having the largest core ever observed in a galaxy, spanning 15,000 light years.〔
== Supermassive black hole ==
The primary component of the galactic core is a supermassive black hole with the currently accepted mass value of 10 billion 〔 Previous estimates by Lauer ''et al'' in equation 26 have jointed a mass value as high as 310 billion 〔 using the gamma ray point break radius method. Kormendy and Bender gave a value of 260 billion in their 3rd equation in a 2009 paper. Lower estimates were given by Kormendy and Ho ''et al'' in 2013 in equations 6 and 7 at 2.1 and 9.2 billion , respectively,〔 and the paper by Lopez-Cruz ''et al''〔 stated: "Therefore, we conservatively suggest that Holm 15A hosts an SMBH with M• ∼ 1 M⊙". Kormendy and Ho ''et al'' derived these equations using the M-sigma relation and the size of the outer bulge of the galaxy, which are indirect estimates. Rusli ''et al'' derived a value of 170 billion using break radius methodology. In addition, Abell 85 has its velocity dispersion of dark matter halo at ~750 km/s, which could only be explained by a black hole with a mass greater than 150 billion , although Kormendy and Ho ''et al'' stated that "dark matter halos are scale-free, and the SMBH-dark matter coevolution is independent from the effects of baryons".〔 This makes it one of the most massive black holes ever discovered.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Holmberg 15A」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|