THE BOLOCAM GALACTIC PLANE SURVEY: {lambda} = 1.1 AND 0.35 mm DUST CONTINUUM EMISSION IN THE GALACTIC CENTER REGION

Journal Article · Mon Sep 20 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/721/1/137· OSTI ID:21464865

Bally, John; Battersby, Cara; Ginsburg, Adam; Glenn, Jason; Harvey, Paul

The Bolocam Galactic Plane Survey (BGPS) data for a 6 deg{sup 2} region of the Galactic plane containing the Galactic center are analyzed and compared to infrared and radio continuum data. The BGPS 1.1 mm emission consists of clumps interconnected by a network of fainter filaments surrounding cavities, a few of which are filled with diffuse near-IR emission indicating the presence of warm dust or with radio continuum characteristic of H II regions or supernova remnants. New 350 {mu}m images of the environments of the two brightest regions, Sgr A and B, are presented. Sgr B2 is the brightest millimeter-emitting clump in the Central Molecular Zone (CMZ) and may be forming the closest analog to a super star cluster in the Galaxy. The CMZ contains the highest concentration of millimeter- and submillimeter-emitting dense clumps in the Galaxy. Most 1.1 mm features at positive longitudes are seen in silhouette against the 3.6-24 {mu}m background observed by the Spitzer Space Telescope. However, only a few clumps at negative longitudes are seen in absorption, confirming the hypothesis that positive longitude clumps in the CMZ tend to be on the near side of the Galactic center, consistent with the suspected orientation of the central bar in our Galaxy. Some 1.1 mm cloud surfaces are seen in emission at 8 {mu}m, presumably due to polycyclic aromatic hydrocarbons. A {approx}0.{sup 0}2 ({approx}30 pc) diameter cavity and infrared bubble between l{approx} 0.{sup 0}0 and 0.{sup 0}2 surround the Arches and Quintuplet clusters and Sgr A. The bubble contains several clumpy dust filaments that point toward Sgr A*; its potential role in their formation is explored. Bania's Clump 2, a feature near l = 3{sup 0}-3.{sup 0}5 which exhibits extremely broad molecular emission lines ({Delta}V> 150 km s{sup -1}), contains dozens of 1.1 mm clumps. These clumps are deficient in near- and mid-infrared emission in the Spitzer images when compared to both the inner Galactic plane and the CMZ. Thus, Bania's Clump 2 is either inefficient in forming stars or is in a pre-stellar phase of clump evolution. The Bolocat catalog of 1.1 mm clumps contains 1428 entries in the Galactic center between l = 358.{sup 0}5 and l = 4.{sup 0}5 of which about 80% are likely to be within about 500 pc of the center. The mass spectrum above about 80 M{sub sun} can be described by a power-law {Delta}N/{Delta}M = N{sub 0} M {sup -2.14(+0.1,-0.4)}. The power-law index is somewhat sensitive to systematic grain temperature variations, may be highly biased by source confusion, and is very sensitive to the spatial filtering inherent in the data acquisition and reduction.

• OSTI ID: 21464865
• Journal Information: Astrophysical Journal, Vol. 721, Issue 1; Other Information: DOI: 10.1088/0004-637X/721/1/137; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABSORPTION
CATALOGS
DUSTS
EMISSION
GALACTIC EVOLUTION
GALAXIES
MASS SPECTRA
POLYCYCLIC AROMATIC HYDROCARBONS
STAR CLUSTERS
STARS
SUPERNOVA REMNANTS
TELESCOPES
AROMATICS
COSMIC RADIO SOURCES
DOCUMENT TYPES
EVOLUTION
HYDROCARBONS
ORGANIC COMPOUNDS
SORPTION
SPECTRA