Date of Award

Spring 1-1-2013

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Astrophysical & Planetary Sciences

First Advisor

John Bally

Second Advisor

Jeremy Darling

Third Advisor

Jason Glenn

Fourth Advisor

Neal Evans

Fifth Advisor

Michael Shull

Abstract

I studied the formation of massive stars and clusters via millimeter, radio, and infrared observations. The Bolocam Galactic Plane Survey (BGPS) was the first millimeter-wave blind survey of the plane of our Galaxy. I wrote the data reduction pipeline for this survey and produced the final publicly released data products. I ran extensive tests of the pipeline, using simulations to probe its performance. The BGPS detected over 8000 1.1 mm sources, the largest sample at this wavelength ever detected. As a single-wavelength continuum survey, the BGPS serves as a finder chart for millimeter and radio observations. I therefore performed follow-up surveys of BGPS sources in CO 3-2 and H2CO, and others did similar follow-ups to measure velocities and distances towards these sources. H2CO observations of ultracompact HII regions and other millimeter-bright sources were used to measure the local molecular gas density. These measurements hint that density within molecular clouds does not follow a simple lognormal distribution. They also show that star-forming clouds all contain gas at density ≳ 104 cm-3. I used the BGPS source catalog to identify the most massive compact clumps within the galaxy, identifying 18 with masses M > 10 4 M M⊙ in the first quadrant of the Galactic plane. As these objects are all actively star-forming, the starless timescale of massive proto-cluster clumps must be relatively short, with lifetimes ≲ 0.6 Myr.

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