Infrared spectra of cooling flow galaxies

We have taken K-band spectra covering seven cooling flow clusters. The spec tra show many of the 1-OS transitions of molecular hydrogen, as well as som e of the higher vibrational transitions, and some lines of ionized hydrogen . The line ratios allow us to conclude that the rotational states of the fi rst excited vibrational state are in approximate local thermodynamic equili brium (LTE), so that densities above 10(5) cm(-3) are likely, but there is evidence that the higher vibrational states are not in LTE. The lack of pre ssure balance between the molecular gas and the ionized components emphasiz es the need for dynamic models of the gas. The ratios of the ionized to mol ecular lines are relatively constant but lower than from starburst regions, indicating that alternative heating mechanisms are necessary.