Velocity split along the rho ophiuchi streamer (north)

It has been found from 13CO observations using the Nagoya 4-m telescope that the blue- and redshifted contours (e.g., VLSR ± 0.5 kms-1) in the ρ Oph streamer (north) are systematically separated from each other, with blue on the north-west side and red on the south-east side of the curved axis of the streamer, respectively. Our interpretation is that the streamer is spinning around its axis. We propose a picture in which the streamer is a 'drain' through which the angular momentum is carried away from a massive cloud of active star formation by the magnetic twist. This draining allows the star-formation process in the massive cloud to occur with an enhanced rate. (author)