Search for HI in E+A galaxies

被引:49
作者
Chang, TC
van Gorkom, JH
Zabludoff, AI
Zaritsky, D
Mihos, JC
机构
[1] Columbia Univ, Dept Astron, New York, NY 10027 USA
[2] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA
[3] Case Western Reserve Univ, Dept Astron, Cleveland, OH 44106 USA
关键词
galaxies; evolution;
D O I
10.1086/319959
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present the results of H I line and radio continuum observations of five nearby E+A galaxies. These galaxies have spectra that are dominated by a young stellar component but lack the emission lines characteristic of significant ongoing star formation. They are selected from a unique sample of 21 E+A's identified by Zabludoff et al. in their spectroscopic search (published in 1996) for E+A galaxies using the Las Campanas Redshift Survey, in which over 11,000 nearby galaxies were examined. The five E+A galaxies span a range of environments: three are in the field, and two are in clusters. Only one system was detected in H I emission, the field E+A galaxy EA 1, with a total flux of 0.30 +/- 0.02 Jy km s(-1) and an H I mass of 3.5 +/- 0.2 x 10(9) h(-2) M-.. The H I morphology and kinematics of EA 1 suggest a galaxy-galaxy interaction, with a dynamical age of similar to6 x 10(8) h(-1) yr inferred from the H I tail lengths and velocities. This age estimate is consistent with the interpretation drawn from optical spectroscopy that starbursts in E+A galaxies began (and subsequently ended) within the last 10(9) yr. Our H I detection limits are such that if the other E+A's in our sample had the H I properties of EA 1, we would have detected (or marginally detected) them. We conclude that E+A galaxies have a range of H I properties. None of the galaxies were detected in radio continuum emission, with upper limits to the radio power of similar to 10(21) h(-2) W Hz(-1). Our limits exclude the possibility that these E+A's are dust-enshrouded massive starburst galaxies, but they are insufficient to exclude modest star formation rates of less than a few h(-2) M-. yr(-1).
引用
收藏
页码:1965 / 1973
页数:9
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