MOLECULAR-HYDROGEN AND PA-ALPHA EMISSION IN COOLING FLOW GALAXIES

We present near-infrared spectra that were obtained in order to search for Pa alpha and molecular hydrogen lines in edge-darkened (FR I-type ) radio galaxies with bright Ha emission in the redshift range 0.0535 < z < 0.15. We find that all three galaxies in our sample (PKS 0745-19 1, PKS 1346+26, and PKS 2322-12) associated with strong cooling flows also have strong Pa alpha and H-2 1-0 S(1) through S(5) emission, whil e other radio galaxies do not. Together with earlier observations, thi s confirms the claims that cooling flow galaxies are copious emitters of molecular hydrogen with large H-2 1-0 S(3)/Pa alpha ratios in the r ange 0.5-2. The emission is centrally concentrated within the inner fe w kiloparsecs and could come from warm (T similar or equal to 1000-150 0 K) molecular material that is being deposited by the cooling flow. W e speculate that the H-2 emission could be related to the interaction between the jets and this molecular gas.