MAGPIS: A Multi-Array Galactic Plane Imaging Survey (2006 AJ Paper)

"MAGPIS: A Multi-Array Galactic Plane Imaging Survey"

Helfand, Becker, White, Fallon, & Tuttle, 2006, Astronomical Journal, 131, 2525

We present the Multi-Array Galactic Plane Imaging Survey (MAGPIS), which maps portions of the first Galactic quadrant with an angular resolution, sensitivity and dynamic range that surpasses existing radio images of the Milky Way by more than an order of magnitude. The source detection threshold at 20 cm is in the range 1-2 mJy over the 85% of the survey region (5° < l < 32°, |b| < 0.8°) not covered by bright extended emission. We catalog over 3000 discrete sources (diameters mostly <30 arcsec) and present an atlas of ~400 diffuse emission regions. New and archival data at 90 cm for the whole survey area are also presented. Comparison of our catalogs and images with the MSX mid-infrared data allow us to provide preliminary discrimination between thermal and non-thermal sources. We identify forty-nine high-probability supernova remnant candidates, increasing by a factor of seven the number of known remnants with diameters smaller than 5 arcmin in the survey region; several are pulsar wind nebula candidates and/or very small diameter remnants (D<45 arcsec). We report the tentative identification of several hundred H II regions based on a comparison with the mid-IR data; they range in size from unresolved ultra-compact sources to large complexes of diffuse emission on scales of half a degree. In several of the latter regions, cospatial nonthermal emission illustrates the interplay between stellar death and birth. We comment briefly on plans for followup observations and our extension of the survey; when complemented by data from ongoing X-ray and mid-IR observations, we expect MAGPIS to provide the most complete census yet obtained of the birth and death of massive stars in the Milky Way.

The paper is available in PDF and gzip-compressed Postscript formats. It is also available through astro-ph.

Note that this paper has not yet completed the refereeing process, so it may change before publication. We are making this preliminary version available because we believe it is useful to users of the MAGPIS data.