English

Observations of Global and Local Infall in NGC 1333

Astrophysics 2009-11-13 v1

Abstract

We report ``infall asymmetry'' in the HCO+^+ (1--0) and (3--2) lines toward NGC 1333, extended over 0.39pc2\sim 0.39 {\rm pc}^2, a larger extent than has been reported be fore, for any star-forming region. The infall asymmetry extends over a major portion of the star-forming complex, and is not limited to a single protostar, or to a single dense core, or to a single spectral line. It seems likely that the infall asymmetry represents inward motions, and that these motions are physically associated with the complex. Both blue-asymmetric and red-asymmetric lines are seen, but in both the (3--2) and (1--0) lines of HCO+^+ the vast majority of the asymmetric lines are blue, indicating inward motions. The (3--2) line, tracing denser gas, has the spectra with the strongest asymmetry and these spectra are associated with the protostars IRAS 4A and 4B, which most likely indicates a warm central source is affecting the line profiles. The (3--2) and (1--0) lines usually have the same sense of asymmetry in common positions, but their profiles differ significantly, and the (1--0) line appears to trace motions on much larger spatial scales than does the (3--2) line. Line profile models fit the spectra well, but do not strongly constrain their parameters. The mass accretion rate of the inward motions is of order 104^{-4} M_\odot/yr, similar to the ratio of stellar mass to cluster age.

Keywords

Cite

@article{arxiv.astro-ph/0510066,
  title  = {Observations of Global and Local Infall in NGC 1333},
  author = {Andrew J. Walsh and Tyler L. Bourke and Philip C. Myers},
  journal= {arXiv preprint arXiv:astro-ph/0510066},
  year   = {2009}
}

Comments

28 pages, 11 figures, 1 colour figure