Long-slit spectroscopy of blue disk galaxies that are located in the central portion of the Coma Cluster reveals the presence of Balmer absorption lines with equivalent widths comparable to those observed for some blue galaxies in the 3C 295 cluster. These anomalously strong Balmer absorption lines indicate the presence of a large population of main sequence A-F stars that has presumably arisen from a relatively recent star formation event. We may be witnessing in Coma the same phenomenon that occurred several billion years ago in the 3C 295 cluster. The authors offer a qualitative model of how enhanced star formation, caused by some interaction of the galaxy with the cluster environment, may be responsible for the prevalence of blue cluster galaxies at high redshift.
No takes yet. Share an insight, caveat, or question.
Bothun et al. (1986) studied this question.