ON THE NATURE OF THE BIPOLAR MOLECULAR OUTFLOW IN AFGL-437

With the IRAM 30 m telescope we have observed the CO(J = 2 --> 1), (CO)-C-13(J = 1 --> 0), and (CO)-O-18(J = 1 --> 0) rotational transition lines toward the AFGL 437 cluster. Our data show a molecular outflow with a north-south bipolarity. This bipolarity is observed in the three lines. An interesting result is that the blue and redshifted lobes are not elongated in the direction of the outflow axis, but in the east-west direction, perpendicularly to the outflow axis. Therefore, AFGL 437 appears to be an outflow with a clear bipolarity, but with a very low collimation. We propose a geometrical model in which the observed bipolar outflow is produced by a laminar flow of dragged molecular gas along the walls of a cavity or hollow, near the edge of the molecular cloud, opened by the stellar winds of the AFGL 437 cluster.