Detection of knots and jets in IRAS 06061+2151

¹ Physical Research Laboratory, Ahmedabad-390009, India
² Department of Astronomy & Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802, USA
³ Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai-400005, India
⁴ National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588, Japan
⁵ Osservatorio Astrofisico di Arcetri, INAF, Largo E. Fermi 5, 50125 Firenze, Italy

Corresponding author: B. G. Anandarao, anand@prl.ernet.in

Received: 26 November 2003
Accepted: 15 March 2004

Abstract

We report detection of a Young Stellar Object with evidence of outflow in the form of knots in the molecular hydrogen emission line (2.121 μm) towards the massive star forming region IRAS 06061+2151. Near-infrared images reveal IRAS 06061+2151 to be a cluster of at least five sources, four of which seem to be early B type young stellar objects, in a region of 12 arcsec surrounded by a nebulosity. The presence of the knots that are probably similar to the HH objects in the optical wavelengths suggests emerging jets from one of the cluster members. These jets appear to excite a pair of knot-like objects (Knot-NW and Knot-SE) and extend over a projected size of 0.5 pc. The driving source of the jets is traced back to a member of the cluster whose position in the s/ color–color diagram indicates that it is a Class I type pre-main sequence star. We also obtained K band spectra of the brightest source in the cluster and of the nearby nebular matter. The spectra show molecular hydrogen emission lines but do not show the Brγ line (2.167 μm). These spectra suggest that the excitation of the molecular hydrogen lines is probably due to a mild shock.