VLA Observations of the Evolved Star-Forming Region SGR B1

Details VLA Observations of the Evolved Star-Forming Region SGR B1 VLA Observations of the Evolved Star-Forming Region SGR B1

Dec 1992

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992aas...18111505m&link_type=abstract

American Astronomical Society, 181st AAS Meeting, #115.05D; Bulletin of the American Astronomical Society, Vol. 24, p.1303

Astronomy and Astrophysics

Astronomy

Scientific paper

Radio continuum, recombination line (RRL), and molecular line observations of Sgr B1 have been carried out using the VLA. This regions is located 0.5(deg) from the Galactic center and about 0.2(deg) southwest of the well studied star-forming region Sgr B2. The continuum observations indicate that Sgr B1 is dominated by many rim- and bar-like structures that are several pc in size. For example, one bar-like structure has a length of 6 pc (assuming a distance of 7.5 kpc). In contrast, most Galactic massive star-forming regions are dominated by compact or ultracompact H II regions. The presence of the extended features in Sgr B1 suggests that this region is evolved. Using an ionized gas expansion velocity of 10 km s(-1) suggests an age of a few times 10(5) yr for the largest features. Formaldehyde observations support the interpretation that this region is evolved. Optical depths are in the range of 0.0 to 0.3. Such low formaldehyde column densities indicate that the molecular gas from which this region formed has dispersed. RRL observations indicate that the kinematics of the ionized gas are quite complex. The western side of the source shows a single line that has a width of ~ 30 km s(-1) , while the eastern side shows multiple lines. The gas on the eastern side displays RRL emission over a velocity range of 120 km s(-1) . Though Sgr B1 may be an evolved region, it appears as though star formation is continuing at present. A search for H_2O masers discovered at least 10 sites of emission. These masers are weak ( ~ 50 to 300 mJy) and, with the exception of one maser site, are not associated with compact H II regions. They are therefore probably associated with intermediate or low mass protostars. Associations between H_2O masers and low mass protostars have been observed in the nearby Taurus-Auriga and rho Oph star-forming complexes (Wilking & Claussen 1987, ApJ, 320, L133; Terebey, Vogel, & Myers 1992, ApJ, 390, 181).

Affiliated with

Also associated with

No associations

Rating

VLA Observations of the Evolved Star-Forming Region SGR B1 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with VLA Observations of the Evolved Star-Forming Region SGR B1, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and VLA Observations of the Evolved Star-Forming Region SGR B1 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1112299