Expanding Molecular Shells in Sagittarius B2

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

High resolution (3 arcsecond) images are presented of the (J,K) = (3,3) and (4,4) transitions of ammonia toward the southern portion of the molecular envelope surrounding the Sagittarius B2 region of high mass star formation near the galactic center. These images reveal, for the first time, that the morphology of the Sagittarius B2 molecular envelope is dominated by several shells (6), incomplete shells (2), and filaments. Several of the shells exhibit ammonia molecular emission at two specific radial velocities; two of the ammonia shells also show a clear systematic velocity gradient indicating expansion. The largest ammonia column densities are found in the intersection of the shells also suggesting expansion. The walls of the shells are warm (>40 K) and contain very compact condensations (< 1 arcsecond), some of which are masering in the ammonia (J,K) = (3,3) transition. We also find several unresolved sources (<1 arcsecond) in the (J,K) = (4,4) transition which show large ammonia densities and temperatures well above 150 K, similar to the Hot Cores found in other regions of massive star formation. These Hot Cores are internally heated and none are associated with centimeter wavelength radio continuum emission, possibly indicating that massive star formation has taken place recently in the molecular envelope of Sgr B2. We discuss the origin of the shells as well as the role of shocks in heating the molecular envelope gas as well as in triggering star formation.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Expanding Molecular Shells in Sagittarius B2 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 Expanding Molecular Shells in Sagittarius B2, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Expanding Molecular Shells in Sagittarius B2 will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1177479

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.