The active source in the region of the Herbig star

by

1 Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze, Italy

2 Dipartimento di Astronomia e Scienza dello Spazio, Universitá di Firenze, Largo E. Fermi, 5, I-50125 Firenze, Italy

3 Department of Physics, Mathematics &Astronomy, Caltech, Pasadena, CA, 91125, USA

4 Astrophysics Division, Space Science Department, ESTEC, Postbus 299, NL-2200 AG Noordwijk, The Netherlands

Abstract:

We present new near-infrared, millimeter and radio observations of the region associated with , a Herbig Be star located in the direction of the Cygnus arm. is the optically brightest member of a small group of young emission line stars, including V1318 Cygni and V1686 Cygni. Near-IR broad-band imaging of V1318 Cygni reveals the presence of two distinct stellar components oriented north-south, a result recently reported by Aspin et al. (1994). On a larger scale, the near-IR images also indicate the presence of many highly embedded sources concentrated in the vicinity of the bright visible stars. In the central part of the cluster, the near-IR sources outnumber the optically visible ones by a factor of three.

The distribution of the high density molecular gas traced by the CS J emission is highly concentrated around V1318 and V1686 Cygni, while the total column density of gas traced by the J shows a ridge morphology centered on these sources. The Herbig star lies at the edge of both structures. From the otpically thin emission, we derive a total molecular mass of . A molecular outflow has been detected in CO J. The high velocity gas is confined to a compact region of size , corresponding to a physical length of 0.1 pc. The outflow is not well resolved, or collimated, on the observed scales. We have also detected maser emission at 22.2 GHz at a position coincident with the center of the bipolar outflow. Both the maser and the outflow are located at the position of the southern source V1318S which we identify as the source responsible for the activity observed in the BD+40 region.


Mantained by: Leonardo Testi

lt@arcetri.astro.it