2004/06/16 by Jorick S. Vink, J. S. Vink, J. E. Drew +7
Engineering · Physics and Astronomy · #Astro and Planetary Science #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Space Exploration and Technology #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0406372
5 pages, 7 figures, to appear in: "Astronomical Polarimetry: Current Status and Future Directions"
arxiv created 2004/06/16 · openalex publication_date 2004/06/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present emission line polarimetry data and modelling relevant to the circumstellar geometry and kinematics around pre-main sequence stars. For a sample of both Herbig Ae/Be stars and T Tauri stars, we find that most show polarization changes across Halpha, implying that flattened structures are common on the smallest scales -- and over a range of stellar masses. We also present Monte Carlo calculations of spectral line profiles scattered in rotating accretion disks. We consider both the case of a central star that emits line photons uniformly, as well as via hot spots. Intriguingly, the switch between a uniform point source and a finite-sized star results in a marked difference in the position angle variation across the line. Our models demonstrate the diagnostic potential of line polarimetry in determining the disk inclination and the size of the inner hole -- a spatial scale no other technique currently accesses.