1 - 0 observations of molecular gas interacting with galactic supernova remnants G 5 . 4 - 1 . 2 , G 5 . 55 + 0 . 32 and G 5 . 71 - 0 . 08 ⋆

Context. The field just West of the galactic supernova remnant W28 (l=6.4 o , b=-0.2 o) harbors 3 of 5 newly-discovered 1720 OH maser spots and two recently-discovered candidate supernova candidates (one of which is a γ-ray source), as well as several compact and classical HII regions. Aims. To show the interaction of radio supernova remnants with ambient molecular gas in sky field just West of W28. Methods. We analyze a datacube of CO J=1-0 emission having 1 ′ and 1 km s −1 resolution, made with on-the-fly mapping over the region 5 o ≤ l ≤ 6 o , −1 o ≤ b ≤ 0.5 o Results. Extended and often very bright CO emission was detected at the velocities of the 1720 MHz OH masers and around the supernova remnant G5.55+0.32 which lacks a maser. A new bipolar outflow which is marginally resolved at 1 ′ resolution and strong in CO (12K) was detected at the periphery of G5.55+0.32, coincident with an MSX source; there is also a bright rim of CO just beyond the periphery of the radio remnant. The OH maser near G5.71-0.08 lies on a shell of strongly-emitting molecular gas (up to 20K). At the-21 km s −1 velocity of G5.4-1.2, CO covers much of the field but is weak (3 K) and undisturbed near the remnant. The extended molecular gas around the compact H II region and outflow in G5.89-0.39 (W28A2) is shown for the first time.