Astronomy and Astrophysics – Astronomy
Scientific paper
Dec 1992
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992aas...181.4807c&link_type=abstract
American Astronomical Society, 181st AAS Meeting, #48.07; Bulletin of the American Astronomical Society, Vol. 24, p.1199
Astronomy and Astrophysics
Astronomy
Scientific paper
We have mapped the nearby small Bok globule LBN 11 (size ~ 0.3 pc, distance ~ 110 pc) in the millimeter lines of CO at very high dispersion (65 m s(-1) per channel), obtained co-added IRAS\ survey images of the cloud, and measured the optical linear polarization of sixteen stars close to the cloud center. The molecular lines and IRAS\ images reveal a low mass cloud ( ~ 2 M_sun) with a moderately dense core (/line{n} <= 10(4.5) cm(-3) ) which has not formed stars. The high spectral resolution CO lines reveal the presence of several individual kinematic and spatial components (``clumps'') within the cloud, which exhibit subsonic linewidths. Such distinct clumping in so small a cloud has not previously been seen. CS and SO maps of the (13) CO core region made at 25('') resolution confirm the presence of the dense gas expected from the radial density distribution inferred from the (13) CO observations. Overall, the cloud is in a state of rotation, with a rotation rate of 3.6 +/- 1.0 km s(-1) \ pc(-1) , for the region strongest in (13) CO emission. The rotation direction, determined from a solid body fit to the CO isotopic lines, lies along PA = -86 +/- 11(deg) . This is parallel to the long axis of the cloud, as well as nearly parallel to the direction of the embedded magnetic field traced by the optical polarizations measured for the 16 stars, PA = 81.6 +/- 0.5(deg) . The dispersion of the projected magnetic field direction is quite small ( ~ 6(deg) ), but is shown to be largest for characteristic spatial separations of 0.1 -- 0.2 pc between pairs of stars. The distributions of CO and (13) CO clump sizes also peak near 0.15 pc, suggesting a possible connection between the magnetic field and the clumpy state of the cloud. The (13) CO clumps may arise from fragmentation of the rapidly rotating core and could signify the presence of a very young protobinary. The CO clumps are transitory and may be due to Alfven waves driven into the cloud periphery.
Ciardi David R.
Clemens Dan P.
Dickman Robert L.
No associations
LandOfFree
The Nearby 2 M_sun BOK Globule LBN 11: Sub-Sonic Molecular Clumps in a Magnetic Environment 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 The Nearby 2 M_sun BOK Globule LBN 11: Sub-Sonic Molecular Clumps in a Magnetic Environment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Nearby 2 M_sun BOK Globule LBN 11: Sub-Sonic Molecular Clumps in a Magnetic Environment will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1110995