Cold gas and dust in cool-core galaxy clusters

Despite the fact that the majority of the baryons in clusters of galaxies reside ill the intracluster medium, we know little about how this gas cools or what process sustains its high temperatures near the core of the cluster. The presence of radio jet inflated bubble near the cores suggests that feedback from the central AGN plays a m1\ior role in suppressing the gas cooling. Many brightest-cluster galaxies ill cool-core clusters are surrounded by networks of filaments, first detected from their optical emission. Recent observations have shown that the filaments have large reservoirs of molecular gas and that they are surrounded by a soft x-ray halo. Central questions include the energy source for the filament emissiol\, the origin of the filaments, and how they relate to feedback processes within the cluster. We propose to fmiher develop the spectral synthesis code Cloudy to do realistic simulations of molecular gas surrounded by a 4 keY plasma. We will investigate the role of charge exchange in producing the X -ray halo sUl1"01Inding the filaments. We will relax the time-steady approximation to better track the nonequilibrium heating processes th'at couple the molecular and low-ionization regions. The radiation transpOlt methods will be advanced [0 do complex geometries like the filaments. These improvements will facilitate Cloudy's applicability to such diverse phenomena as starburst galaxies, gamma ray bursts, and the intergalactic medium.