A study of dense molecular gas towards galactic TeV γ-ray sources

Abstract

H.E.S.S. has revealed many new TeV ?-ray sources along the Galactic Plane. Many of these sources do not have identified counterparts at other wavelengths. The morphology and dynamics of dense gas can provide insight into the conditions of the interstellar medium coincident and surrounding the ?-ray emission, which can also provide clues about the nature of the TeV emission. The H2O Galactic Plane Survey (HOPS) undertaken with the Mopra radio telescope, includes several dense gas tracers, such as NH3 (n,n) transitions and HC3N (3-2), star formation tracers including H2O masers, and radio recombination lines which trace ionised gas. The HOPS data and additional observations undertaken by the authors have been used to search for dense gas toward Galactic TeV sources. Preliminary results towards a selected sample of three TeV sources are presented here