MUSCLE W49: A MULTI-SCALE CONTINUUM AND LINE EXPLORATION OF THE MOST LUMINOUS STAR FORMATION REGION IN THE MILKY WAY. I. DATA AND THE MASS STRUCTURE OF THE GIANT MOLECULAR CLOUD

The Multi-scale Continuum and Line Exploration of W49 is a comprehensive gas and dust survey of the giant molecular cloud (GMC) of W49A, the most luminous star-formation region in the Milky Way. In this paper, we present (1) an all-configuration Submillimeter Array mosaic in the 230 GHz (1.3 mm) band covering the central ~3' x 3' (~10 pc, known as W49N), where most of the embedded massive stars reside and (2) Purple Mountain Observatory 14 m telescope observations in the 90 GHz band, covering the entire GMC with maps of up to ~35' x 35' in size, or ~113 pc. We also make use of archival data from the Very Large Array, JCMT-SCUBA, the IRAM 30 m telescope, and the Caltech Submillimeter Observatory BOLOCAM Galactic Plane Survey. The resulting stellar content will probably remain as a gravitationally bound massive star cluster or a small system of bound clusters.