2016/01/18 by L. K. Dewangan, D. K. Ojha, A. Luna +5 · 2 citations
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.3847/0004-637x/819/1/66
28 pages, 15 figures, 3 tables, Accepted for publication in The Astrophysical Journal
arxiv created 2016/01/18 · openalex publication_date 2016/02/29 · arxiv updated 2016/03/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We have carried out an extensive multi-wavelength study to investigate the star formation process in the S235 complex. The S235 complex has a sphere-like shell appearance at wavelengths longer than 2 μm and harbors an O9.5V type star approximately at its center. Near-infrared extinction map traces eight subregions (having AV > 8 mag), and five of them appear to be distributed in an almost regularly spaced manner along the sphere-like shell surrounding the ionized emission. This picture is also supported by the integrated 12CO and 13CO intensity maps and by Bolocam 1.1 mm continuum emission. The position-velocity analysis of CO reveals an almost semi-ring like structure, suggesting an expanding H \sc ii region. We find that the Bolocam clump masses increase as we move away from the location of the ionizing star. This correlation is seen only for those clumps which are distributed near the edges of the shell. Photometric analysis reveals 435 young stellar objects (YSOs), 59% of which are found in clusters. Six subregions (including five located near the edges of the shell) are very well correlated with the dust clumps, CO gas, and YSOs. The average values of Mach numbers derived using NH3 data for three (East~1, East~2, and Central~E) out of these six subregions are 2.9, 2.3, and 2.9, indicating these subregions are supersonic. The molecular outflows are detected in these three subregions, further confirming the on-going star formation activity. Together, all these results are interpreted as observational evidence of positive feedback of a massive star.