Study of star formation in RCW 106 using far infrared observations

High resolution far-infrared observations of a large area of the star forming complex RCW 106 obtained using the TIFR 1m balloon-borne telescope are presented. Intensity maps have been obtained simultaneously in two bands centred around 150 and 210 µm. Intensity maps have also been obtained at the four IRAS bands using HIRES processed IRAS data. From the 150 and 210 µm maps, reliable maps of dust temperature and optical depth have been generated. The star formation in this complex has occurred in five linear sub-clumps. Using the map at 210 µm, which has a spatial resolution superior to that of the IRAS at 100 µm, 23 sources have been identified. The spectral energy distribution (SED) and luminosity of these sources have been determined using the associations with the IRAS maps. Luminosity distribution of these sources has been obtained. Assuming these embedded sources to be ZAMS stars and using the mass-luminosity relation for these, the power law slope of the initial mass function is found to be −1.73 ± 0.5. This index for this very young complex is about the same as that for more evolved complexes and clusters. Radiation transfer calculations in spherically symmetric geometry have been undertaken to fit the SEDs of 13 sources with fluxes in both the TIFR and the IRAS bands. From this, the r −2 density distribution in the envelopes is ruled out. Finally, a correlation is seen between the luminosity of embedded sources and the computed dust masses of the envelopes.