有哪些信誉好的足球投注网站- 1、本文档共11页，可阅读全部内容。
- 2、有哪些信誉好的足球投注网站（book118）网站文档一经付费（服务费），不意味着购买了该文档的版权，仅供个人/单位学习、研究之用，不得用于商业用途，未经授权，严禁复制、发行、汇编、翻译或者网络传播等，侵权必究。
- 3、本站所有内容均由合作方或网友上传，本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺！文档内容仅供研究参考，付费前请自行鉴别。如您付费，意味着您自己接受本站规则且自行承担风险，本站不退款、不进行额外附加服务；查看《如何避免下载的几个坑》。如果您已付费下载过本站文档，您可以点击 这里二次下载。
- 4、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等，请点击“版权申诉”（推荐），也可以打举报电话：400-050-0827(电话支持时间：9:00-18:30)。
查看更多
Absence of Dwarf Galaxies at High Redshifts Evidence from a Galaxy Group
a
r
X
i
v
:
a
s
t
r
o
-
p
h
/
0
4
0
8
1
4
4
v
1
9
A
u
g
2
0
0
4
Draft version February 2, 2008
Preprint typeset using LATEX style emulateapj v. 14/09/00
ABSENCE OF DWARF GALAXIES AT HIGH REDSHIFTS: EVIDENCE FROM A GALAXY
GROUP
William G. Mathews1, Laura Chomiuk1, Fabrizio Brighenti12, David A. Buote3
Draft version February 2, 2008
ABSTRACT
The galaxy group NGC 5044 consists of a luminous giant elliptical galaxy surrounded by a cluster
of ～ 160 low luminosity and dwarf galaxies, mostly of early type. The cumulative projected radial
distribution of dwarf galaxies in the NGC 5044 group, unlike distributions of more luminous galaxies
in rich clusters, does not follow a projected dark matter (NFW) profile. A deficiency or absence of low
luminosity galaxies is apparent in NGC 5044 within about 350 kpc. Most of the dwarf galaxies in NGC
5044 entered the virial radius at redshifts z ～ 2 ? 3(af/0.25), where af = 1/(1 + zf ) is the epoch of
group formation, and very few entered during redshifts z ～ 2 ? 3(af/0.25). The peculiar, non-NFW
shape of the projected cumulative dwarf galaxy distribution in NGC 5044 within 350 kpc resembles
the characteristic cumulative distribution of dark subhalos that are also known to be relatively young.
Dynamical friction is unlikely to explain the apparent lack of group member galaxies at small radii in
NGC 5044.
Subject headings: galaxies: elliptical and lenticular, CD – galaxies: dwarfs – clusters – groups –
feedback
1. introduction
The early evolution of dwarf galaxies is of interest be-
cause of the possible great antiquity of these galaxies and
because they lie near the lowest mass scale for hierarchi-
cal assembly in which low mass galaxies merge to form
normal galaxies of larger mass. Efforts to understand the
evolution of these faint galaxies have been frustrated be-
cause of the difficulty of direct observation at cosmolog-
ically relevant redshifts. Theoretical models of the for-
mation of dwarf galaxies are complicated by the po
您可能关注的文档
- 2015年4月30日雅思写作真题解析与自撰范文.pdf
- 2015年7月全月雅思口语考试预测—智课教育独家揭秘-智课教育出国考试.pdf
- 2015年8月二期,经典《龙珠》回归.pdf
- 2015年8月四期,生命的尽头更坚强.pdf
- 2015年9月20号GRE阅读机经解析之长阅读.docx
- 2015年5月10日GRE填空部分真题总结-智课教育旗下智课教育.pdf
- 2015年ACCA考试P3考点归纳.pdf
- 2015年北二外基础英语考研真题,复习经验,考研重点,考研大纲,考研参考书.pdf
- 2015年北二外基础西班牙语考研真题,复习经验,考研重点,考研大纲,考研参考书.pdf
- 2015年北京第二外国语学院国际贸易学考研真题,复习经验,考研重点,考研大纲,考研参考书.pdf
文档评论（0）