Accession Number : ADA018362

Title :   CO Observations of NGC1579 (S222) and S239,


Personal Author(s) : Knapp,G. R. ; Kuiper,T. B. H. ; Knapp,S. L. ; Brown,Robert L.

Report Date : 1975

Pagination or Media Count : 35

Abstract : The 2.6-mm lines of 12CO and 13CO have been observed towards the small galactic diffuse nebulae NGC1579 (s222) and s239. The H92 alpha recombination line has also been detected from NGC1579. Towards NGC1579, we have observed evidence for self-absorption in the 12CO line. For both regions, high-velocity wings and line broadening are observable in the 12CO line; the features observed towards s239 suggest ordered, free-fall collapse of a localized region of the cloud onto a newborn stellar cluster. Examination of the available data suggests that NGC1579 is both a reflection nebula (illuminated by LkH alpha 101), and an obscured HII region excited by a star of spectral type near B1, while S239 is a reflection nebula or a Herbig-Haro object. Our studies of these regions show that line widening in CO is at least as important an indicator of star-formation activity as enhanced line emission. (Author)

Descriptors :   *Galaxies, *Line spectra, *Radio astronomy, Interstellar matter, Carbon monoxide, Spatial distribution, Resolution, Nebulae, Emission spectra

Subject Categories : Astrophysics
      Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE