Shocked molecular material associated with the supernova remnant G33.6 + 0.1?

|¹²CO\,J=1→ 0\,and\,HCO⁺\,J=1→ 0| observations towards the supernova remnant G33.6 + 0.1 have been made with the National Radio Astronomy Observatory (NRAO) 12-m telescope. Previous observations showed an unusually broad OH absorption feature near + 105 km s–1 towards this remnant (which is consistent with the distance of the remnant inferred from H I absorption studies), possibly indicating interaction with a nearby molecular cloud. The present results reveal bright |(TR\,up to≈ 1\,K)\,HCO⁺| emission from the east and south-east of the remnant, at velocities near + 105 km s–1, where CO observations indicate a molecular cloud across the face of the remnant. This HCO+ probably emanates from material shocked by the interaction of the remnant with the adjacent molecular cloud.