Speaker
Guangxing Li
(MPIfR)
Description
Guang-Xing Li, Friedrich Wyrowski, Karl Menten and Arnaud Belloche
Max-Planck Institut fuer Radioastronomie, Bonn, Germany
Star formation occurs in molecular gas. In the previous studies, the structure of the molecular gas has been studied in terms of molecular clouds, but overlooked beyond the cloud scale. In this work, we present an observational study of the molecular gas at l~ 50. The molecular gas is found in the form of a huge (~ 500 pc) filamentary gas wisp. The gas wisp has a large physical extent and a velocity dispersion of 5 km/s. The eastern part of the filamentary gas wisp is 130 pc above the Galactic disk (which corresponds to 1.5--4 e-folding scale-heights), and the total mass of the gas wisp is >= 1e5 solar mass. The gas wisp is composed of two molecular clouds and an expanding bubble. The velocity structure of the gas wisp can be explained as a smooth quiescent
component disturbed by the expansion of a bubble. The fact that the length of the gas wisp is much larger than the thickness of the molecular disk of the Milky Way is consistent with the cloud formation scenario in which the gas is cold prior to the formation of molecular clouds. Star formation in the filamentary gas wisp occurs at the edge of a bubble, which is consistent with some models of triggered star
formation.
Author
Guangxing Li
(MPIfR)