Ram pressure stripping of an isolated Local Group dwarf galaxy: Evidence for an intragroup medium

被引：43
作者：
McConnachie, Alan W. [1 ]
Venn, Kim A. [1 ]
Irwin, Mike J. [2 ]
Young, Lisa M. [3 ]
Geehan, Jonathan J. [1 ]
机构：
[1] Univ Victoria, Dept Phys & Astron, Victoria, BC, Canada
[2] Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England
[3] New Mexico Inst Min & Technol, Dept Phys, Socorro, NM 87801 USA
来源：
ASTROPHYSICAL JOURNAL LETTERS | 2007年 / 671卷 / 01期
基金：
英国科学技术设施理事会;
关键词：
galaxies : dwarf; galaxies; individual; (Pegasus; DDO; 216); galaxies : interactions; galaxies : structure; intergalactic medium; Local Group;
D O I：
10.1086/524887
中图分类号：
P1 [天文学];
学科分类号：
0704 ;
摘要：
We compare the stellar structure of the isolated, Local Group dwarf galaxy Pegasus (DDO 216) with low-resolution H I maps from L. M. Young et al. Our comparison reveals that Pegasus displays the characteristic morphology of ram pressure stripping; in particular, the H I has a "cometary" appearance that is not reflected in the regular, elliptical distribution of the stars. This is the first time this phenomenon has been observed in an isolated Local Group galaxy. The density of the medium required to ram pressure strip Pegasus is at least 10(-5) to 10(-6) cm(-3). We conclude that this is strong evidence for an intergalactic medium associated with the Local Group.
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页码：L33 / L36
页数：4
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