University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Colloquium

Wednesday, April 1st 2009
3:35 pm:
Speaker: Prof. Gary J. Ferland, University of Kentucky
Subject: What powers the intra-cluster filaments in large clusters of galaxies?
Refreshments served in Room 216 Physics after colloquium

The first radio surveys of the sky discovered that some large clusters of galaxies contained powerful sources of synchrotron emission. Optical images showed that the intra-cluster medium was permeated by long linear filaments with bizarre emission line spectra. Recent observations in the infrared and radio show that these filaments have very strong emission lines of molecular
hydrogen and carbon monoxide. The mass of molecular material is quite large, the gas is quite warm, and the filaments have not formed stars despite their multi-Gyr age. I will discuss the general astrophysical context of large clusters of galaxies and how large masses of molecular gas can be heated to produce what we observe.

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