The young stellar cluster towards IRAS 03523+5343

Abstract

We present a study of the star formation occurring in the most active region of a molecular cloud in the second quadrant of the (outer) Galaxy towards IRAS 03523+5343. Near-infrared $JH{K}_S$ images and $K$-band spectroscopy were obtained with NOTCam at the Nordic Optical Telescope at the Roque de Los Muchachos Observatory. Mid-infrared WISE satellite images and submm JCMT/SCUBA-2 catalogue sources were also explored. In addition, millimetre line CS spectra were obtained with the Yebes 40 m telescope.

Within the region of the molecular cloud covered by our CS $(J=1-0)$ maps, the line is strong and extends over all the mapped region of $3.7^{\prime }\times 3.7^{\prime }$. This high-density molecular gas defines a molecular core exhibiting an angular size FWHM of about $1^{\prime }$ (0.7 pc at 2.4 kpc distance). We estimate a lower limit to the mass of the molecular gas in this region to be about 995 $M_{\odot }$. A SCUBA-2 core was detected with an estimated total mass of 250 $M_{\odot }$.

We identify a young stellar cluster with a few hundred sources with colours compatible to YSOs at the location of a strong enhancement of the stellar density coincident with the IRAS position. The main counterpart of the IRAS source is a very red and bright source with radio jets likely to be a high-mass young stellar object. A second bright source is a Herbig Be candidate source displaying a blue nebula with a morphology that suggests the dissipation of a collimated flow.