A MULTIWAVELENGTH STUDY OF IRAS 19550- A PROTOSTAR POSSIBLE FORMED BYA CLOUD-CLOUD COLLISION(3248 )

We have carried out radio, near-infrared, and optical observations of the IRAS point source IRAS 19550 + 3248. (CO)-C-12 j = 1-0 line observ ations revealed a high-velocity (HV) molecular outflow centered on IRA S 19550 + 3248. The HV gas has a bipolar pattern with the blue and red peaks separated by 1' along the north-south direction. The mechanical luminosity of the HV molecular outflow is approximately 9 x 10(31)d2 ergs s-1, and its dynamical age is approximately 5 x 10(4)d2 yr, where d2 is the distance to the source normalized to 2 kpc. Inside the 95% confidence ellipse of IRAS position, we have detected a nebulous K ban d source. The nebulosity extends to 0.1d2 pc in the east-west directio n. In R and I bands, the source appears to be composed of two extended weak peaks shifted toward the blueshifted CO lobe from the peak posit ion in K band. These near-infrared emission features are likely scatte red stellar light. The infrared source has a steep spectral index betw een 2 and 25 mum (d log [nuF(nu)]/d log nu = -0.93), which indicates t hat it is a protostar deeply embedded in a dense molecular cloud core. The bolometric luminosity based on R, I, H, and K band photometry tog ether with the IRAS data is 150d2(2)L.. IRAS 19550 + 3248 is located a t the center of a small (4' x 7') dense molecular clump. The clump is at the tip of a long (approximately 1-degrees) filamentary molecular c loud. The molecular cloud is composed of clumps which are not confined by gravity and nor, probably, by external pressure. The characteristi c timescale for dispersal is approximately 6 x 10(6) yr. We suggest cl oud-cloud collision as a possible mechanism for the disruption of the cloud and for the formation of IRAS 19550 + 3248.