TRIGONOMETRIC PARALLAXES OF MASSIVE STAR-FORMING REGIONS. VII. G9.62+0.20 AND THE EXPANDING 3 kpc ARM

Journal Article · Fri Nov 20 04:00:00 EST 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/706/1/464· OSTI ID:21378173

Sanna, A ^[1]; Reid, M J; Dame, T M ^[2]; Moscadelli, L ^[3]; Menten, K M; Brunthaler, A ^[4]; Zheng, X W ^[5]; Xu, Y ^[6]

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1. Dipartimento di fisica, Universita degli Studi di Cagliari, S.P. Monserrato-Sestu km 0.7, I-09042 Cagliari (Italy)
2. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
3. INAF, Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze (Italy)
4. Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany)
5. Department of Astronomy, Nanjing University, Nanjing 210093 (China)
6. Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210093 (China)

We report a trigonometric parallax of 12 GHz methanol masers associated with the massive star-forming region G9.62+0.20, corresponding to a distance of 5.2{sup +0.6} {sub -0.6} kpc. With an LSR velocity of about 2 km s{sup -1}, the region's kinematic distances of 0.5 and 16 kpc differ greatly from the distance derived here. Our measurement of the peculiar motion of the star-forming region shows a very large deviation from a circular Galactic orbit: 41 km s{sup -1} radially outward from the Galactic center and 60 km s{sup -1} counter to Galactic rotation. The combination of its radial velocity and distance places G9.62+0.20 in the inner region of the Galaxy close to the expanding near 3 kpc arm, where the bulge/bar potential has strong gravitational influence. We also map the distribution of 12 GHz methanol masers, locate them with respect to a hypercompact H II region, and compare our data with the periodic flare phenomenon reported previously for this source.

• OSTI ID: 21378173
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 706; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ALCOHOLS
AMPLIFIERS
DISTANCE
ELECTRONIC EQUIPMENT
EQUIPMENT
FREQUENCY RANGE
GALAXIES
GHZ RANGE
GHZ RANGE 01-100
HYDROXY COMPOUNDS
MASERS
METHANOL
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
MOTION
ORGANIC COMPOUNDS
PERIODICITY
RADIAL VELOCITY
ROTATION
STARS
VARIATIONS
VELOCITY