The origin of molecular striae aligned along the local magnetic field in the envelope of the Taurus molecular cloud is examined with new observations of 12CO and 13CO J=2-1 emission obtained with the 10m submillimeter telescope of the Arizona Radio Observatory. These data identify a periodic pattern of excess blue and redshifted emission that is responsibe for the striae features. For both 12CO and 13CO, spatial variations of the J=2-1 to J=1-0 line ratio are small and are not spatially correlated with the striae locations. A medium comprised of small, unresolved cells of CO emission with a filling factor less than 1 is required to explain the average line ratios and brightness temperatures. We propose that the striae features result from the modulation of the velocities and the beam filling factor of the cells, as a result of magnetosonic waves propagating through the envelope of the Taurus molecular cloud. Such waves are likely a common feature of molecular clouds that are sub-Alfvenic and may explain low column density, cirrus-like features that are observed to be aligned along the magnetic field direction.
American Astronomical Society Meeting Abstracts #229
- Pub Date:
- January 2017