The Bolocam Galactic Plane Survey. IX. Data release 2 and outer galaxy extension

We present a re-reduction and expansion of the Bolocam Galactic Plane Survey (BGPS), first presented by Aguirre et al. and Rosolowsky et al. The BGPS is a 1.1 mm survey of dust emission in the Northern galactic plane, covering longitudes -10° < ℓ < 90°and latitudes |b| < 0.°5 with a typical 1σ rms sensitivity of 30-100 mJy in a c33″ beam. Version 2 of the survey includes an additional 20 deg² of coverage in the third and fourth quadrants and 2 deg² in the first quadrant. The new data release has improved angular recovery, with complete recovery out to 80″ and partial recovery to 300″, and reduced negative bowls around bright sources resulting from the atmospheric subtraction process. We resolve the factor of 1.5 flux calibration offset between the v1.0 data release and other data sets and determine that there is no offset between v2.0 and other data sets. The v2.0 pointing accuracy is tested against other surveys and is demonstrated to be accurate and an improvement over v1.0. We present simulations and tests of the pipeline and its properties, including measurements of the pipeline's angular transfer function. The Bolocat cataloging tool was used to extract a new catalog, which includes 8594 sources, with 591 in the expanded regions. We have demonstrated that the Bolocat 40″ and 80″ apertures are accurate even in the presence of strong extended background emission. The number of sources is lower than in v1.0, but the amount of flux and area included in identified sources is larger.