HOPS: The H₂O Southern Galactic Plane Survey

¹ Centre for Astronomy, James Cook University, Townsville, QLD, 4811, Australia
² School of Mathematics and Physics, University of Tasmania, GPO Box 252-37, Hobart 7001, TAS, Australia
³ CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1701, Australia
⁴ School of Physics, University of NSW, NSW 2052, Australia
⁵ Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Herts AL10 9AB, UK
⁶ School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
⁷ Departmento de Astronomía, Universidad de Chile, Camino El Observat orio 1515, Las Condes, Santiago, Casilla 36-D, Chile
⁸ Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
⁹ School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK

Abstract

Over the past 3 years, we have conducted a survey of 100 square degrees of the southern Galactic plane with the Mopra radiotelescope (HOPS). The survey includes observations of multiple spectral lines in the 12 mm band, with the most important being the water maser transition at 22.2 GHz and the non-metastable inversion transitions of ammonia. We report on initial results from HOPS, including the detection of 540 water masers, about two-thirds of which appear to be new detections. We also find widespread emission in the NH₃ (1,1) line, as well as detec tions in the NH₃ (2,2), (3,3), (6,6) and (9,9) lines.