Investigation of Dense Gas Towards Relativistic Outflow Sources
  We probe the interstellar medium towards the objects Circinus X-1, a low-mass X-ray binary with relativistic jets; and the highly energetic Westerlund 2 stellar cluster, which is located towards TeV gamma-ray emission and interesting arc- and jet-like features seen in Nanten 12CO data. We have mapped both regions with the Mopra radio telescope, in 7 mm and 12 mm wavebands, looking for evidence of disrupted/dense gas caused by the interaction between high energy outflows and the ISM. Towards Westerlund 2, peaks in CS(J=1-0) emission indicate high density gas towards the middle of the arc and the endpoint of the jet; and radio recombination line emission is seen overlapping the coincident HII region RCW49. Towards Circinus X-1, 12CO(J=1-0) Nanten data reveals three molecular clouds that lie in the region of Cir X-1. Gas parameters for each cloud are presented here. 
J. Hawkes, G. Rowell, B. Dawson, F. Aharonian, M. Burton, Y. Fukui, N.   Furukawa, T. Hayakawa, A. Kawamura, N. Maxted, E. d...
astro-ph.HE astro-ph.GA