2009/04/09 by Joan R. Najita, Joan Najita, Greg W. Doppmann +14 · 4 citations
Physics and Astronomy · #Astrophysics and Star Formation Studies #Atomic and Molecular Physics #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1088/0004-637x/697/1/957
published as Astrophys.J.697:957-963,2009 · Accepted for publication in ApJ
arxiv created 2009/04/09 · openalex publication_date 2009/05/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We present high-resolution ( R = 80,000) spectroscopy of [Ne ii ] emission from two young stars, GM Aur and AA Tau, which have moderate to high inclinations. The emission from both sources appears centered near the stellar velocity and is broader than the [Ne ii ] emission measured previously for the face-on disk system TW Hya. These properties are consistent with a disk origin for the [Ne ii ] emission we detect, with disk rotation (rather than photoevaporation or turbulence in a hot disk atmosphere) playing the dominant role in the origin of the line width. In the non-face-on systems, the [Ne ii ] emission is narrower than the CO fundamental emission from the same sources. If the widths of both diagnostics are dominated by Keplerian rotation, this suggests that the [Ne ii ] emission arises from larger disk radii on average than does the CO emission. The equivalent width of the [Ne ii ] emission we detect is less than that of the spectrally unresolved [Ne ii ] feature in the Spitzer spectra of the same sources. Variability in the [Ne ii ] emission or the mid-infrared continuum, a spatially extended [Ne ii ] component, or a very (spectrally) broad [Ne ii ] component might account for the difference in the equivalent widths.