IONIZED GAS KINEMATICS AND MORPHOLOGY IN Sgr B2 Main ON 1000 AU SCALES

Journal Article · Tue Nov 15 04:00:00 EST 2011 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/142/5/177· OSTI ID:22034359

De Pree, C G ^[1]; Wilner, D J ^[2]

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1. Department of Physics and Astronomy, Agnes Scott College, Decatur, GA 30030 (United States)
2. Harvard Center for Astrophysics, Cambridge, MA (United States)

We have imaged the Sgr B2 Main region with the Very Large Array in the BnA configuration ({theta}{sub beam} = 0.''13) in both the H52{alpha} (45.453 GHz) radio recombination line and 7 mm continuum emission. At a distance of 8500 pc, this spatial resolution corresponds to a physical scale of 0.005 pc ({approx}1100 AU). The current observations detect H52{alpha} emission in 12 individual ultracompact and hypercompact H II regions. Two of the sources with detected H52{alpha} emission have broad ({Delta}V{sub FWHM} {approx} 50 km s{sup -1}) recombination lines, and two of the sources show lines with peaks at more than one velocity. We use line parameters from the H52{alpha} lines and our previous H66{alpha} line observations to determine the relative contribution of thermal, pressure, and kinematic broadening, and electron density. These new observations suggest that pressure broadening can account for the broad lines in some of the sources, but that gas motions (e.g., turbulence, accretion, or outflow) contribute significantly to the broad lines in at least one of the sources (Sgr B2 F3).

• OSTI ID: 22034359
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 5 Vol. 142; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
CONFIGURATION
ELECTRON DENSITY
GHZ RANGE
MORPHOLOGY
PHOTON EMISSION
RECOMBINATION
SPATIAL RESOLUTION
STARS
TURBULENCE
VELOCITY