2005/10/04 by Andrew Walsh, Andrew J. Walsh, Tyler L. Bourke +1
Earth and Planetary Sciences · Physics and Astronomy · #Accretion (finance) #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Asymmetry #Atmospheric Ozone and Climate #Geometry #Line (geometry) #Physics #Protostar #Spectral line #Star formation #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/498564
published as Astrophys.J.637:860-868,2006 · 28 pages, 11 figures, 1 colour figure
arxiv created 2005/10/04 · openalex publication_date 2006/01/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We report "infall asymmetry" in the HCO + (1-0) and (3-2) lines toward NGC 1333, extended over ~0.39 pc 2 , a larger extent than has been reported before 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, a single dense core, or 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; these spectra are associated with the protostars IRAS 4A and 4B, which most likely indicates that 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 10 -4 M ☉ yr -1 , similar to the ratio of stellar mass to cluster age.