2001/01/23 by Tzu-Ching Chang, Tzu‐Ching Chang, Jacqueline H. van Gorkom +5 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/319959
21 Latex pages, including 5 figures and 6 tables. Uses Aastex. To appear in AJ, April 2001; minor changes to text and Figure 4
arxiv created 2001/01/23 · openalex publication_date 2001/04/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
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 × 10 9 h -2 M ⊙ . The H I morphology and kinematics of EA 1 suggest a galaxy-galaxy interaction, with a dynamical age of ∼6 × 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 ∼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 .