CO Observations of NGC1579 (S222) and S239,

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)

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1975
Accession Number
ADA018362

Entities

People

  • G. R. Knapp
  • Robert L. Brown
  • S. L. Knapp
  • T. B. H. Kuiper

Organizations

  • Owens Valley Radio Observatory

Tags

DTIC Thesaurus Topics

  • Absorption
  • Acquisition
  • Collapse
  • Data Acquisition
  • Emission
  • Failure (Mechanics)
  • Indicators
  • Mechanical Phenomena
  • Motion
  • Observation
  • Reflection

Fields of Study

  • Physics

Readers

  • Astronomy/Astrophysics
  • Spectroscopy.