2005/09/22 by R. D. Oudmaijer, J. E. Drew, J. S. Vink · 2 citations
Chemistry · Physics and Astronomy · #Astrophysics and Star Formation Studies #Molecular Spectroscopy and Structure #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2005.09598.x
published as Mon.Not.Roy.Astron.Soc.364:725-730,2005 · 6 pages, MNRAS in press
arxiv created 2005/09/22 · openalex publication_date 2005/10/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In order to study the inner parts of the circumstellar material around optically faint infrared bright objects, we present the first medium-resolution spectropolarimetric data taken in the near-infrared. In this paper, we discuss Paβ line data of GL 490, a well-known embedded massive young stellar object, and of MWC 349A and MWC 342, two optically faint stars that are proposed to be in the pre-main-sequence phase of evolution. As a check on the method, the classical Be star ζ Tau, known to display line polarization changes at optical wavelengths, was observed as well. Three of our targets show a ‘line effect’ across Paβ. For ζ Tau and MWC 349A, this line effect is due to depolarization by a circumstellar electron-scattering disc. In both cases, the position angle of the polarization is consistent with that of the larger scale discs imaged at other wavelengths, validating infrared spectropolarimetry as a means to detect flattening on small scales. The tentative detection of a rotation in the polarization position angle at Paβ in the embedded massive young stellar object GL 490 suggests the presence of a small-scale rotating accretion disc with an inner hole — similar to those recently discovered at optical wavelengths in Herbig Ae and T Tauri stars.