A search for H I in E + A galaxies

Tzu Ching Chang, Jacqueline H. Van Gorkom, Ann I. Zabludoff, Dennis Zaritsky, J. Christopher Mihos

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

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 × 109 h-2 M⊙. The H I morphology and kinematics of EA 1 suggest a galaxy-galaxy interaction, with a dynamical age of ∼6 × 108 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 109 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 ∼1021 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.

Original languageEnglish (US)
Pages (from-to)1965-1973
Number of pages9
JournalAstronomical Journal
Volume121
Issue number4
DOIs
StatePublished - Apr 2001

Keywords

  • Galaxies: evolution

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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