NRAO/Socorro Colloquium Series

Neal Miller

John Hopkins University


Galaxy Evolution in the Coma Cluster


Coma holds an exalted position among clusters of galaxies on account of its proximity, richness, and ease of observation. Even with the great wealth of prior observational campaigns and findings, the Coma cluster continues to provide insights into the evolution of galaxies in the cluster environment. I will provide an overview of new multiwavelength data being assembled for Coma, including space-based observations made with HST, Spitzer, GALEX, Chandra, and XMM along with deep ground-based optical spectroscopy and a VLA 20cm radio continuum survey. In particular, I will focus on exciting new results on galaxy evolution determined from these ground-based data. The optical spectroscopy shows a strong environmental dependence in the ages of dwarf galaxies such that younger dwarfs are found in the cluster outskirts, as would be expected if such objects resulted from environmental transformation of infalling late-type galaxies. Similarly, the radio-selected population of star-forming galaxies is dominated by strong starbursts instead of star-forming galaxies with more typical star formation histories. Surprisingly, star-forming galaxies appear to be absent at the fainter radio luminosities probed by the observations although their decline is roughly offset by AGN hosted in massive elliptical galaxies. In fact, nearly all massive ellipticals prove to be radio sources. However, we find no evidence for a population of dwarf ellipticals hosting relatively powerful radio AGN.






September 19, 2008
11:00 AM

Array Operations Center Auditorium

All NRAO employees are invited to attend via video, available in Charlottesville Room ER209, Green Bank BSMT and Tucson N525.

Local Host: Dale Frail