A study of the Galactic star forming region

We present infrared and radio continuum observations of S 201 star forming region. A massive star cluster is observed in this region, which contains different classes of young stellar objects. The near-infrared colour-colour and colour-magnitude diagrams are studied to discuss the nature of these sources. We have discovered the knots of molecular hydrogen emission at 2.122 µm in the central region of S 201. These knots are clearly seen along the diffuse emission in north–west direction which are probably the obscured Herbig-Haro objects. High sensitivity and high resolution radio continuum images from GMRT observations at 610 and 1280 MHz show an interesting arc-shaped structure due to the interaction between the HII region and the adjacent molecular cloud. The ionization front at the interface between the HII region and the molecular cloud is clearly seen by comparing the radio, molecular hydrogen and Brγ images. The emission from the carriers of Unidentified Infrared Bands in the mid-infrared 6–9 µm (possibly due to PAHs) as extracted from the Midcourse Space Experiment survey (at 8, 12, 14 and 21 µm) is compared with the radio emission. The HIRES processed IRAS maps at 12, 25, 60, and 100 µm, have also been used for comparison. The spatial distribution of the temperature and the optical depth of the warm dust component around S 201 region, has been generated from the mid-infrared images.