Open AccessDiscs and the 10‐ μ m silicate spectra of young stellar objects with non‐photospheric continua
Author(s) -
Bowey J. E.,
Adamson A. J.
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.03955.x
Subject(s) - physics , astrophysics , silicate , extinction (optical mineralogy) , t tauri star , spectral line , absorption (acoustics) , stars , astronomy , optics
Dust emission in the non‐photospheric 10‐μm continua of HL Tau and Taurus‐Elias 7 (Haro6‐10, GV Tau) is distinguished from foreground silicate absorption using a simple disc model with radial power‐law temperature and mass–density distributions based on the IR–submm model of T Tauri stars by Adams, Lada & Shu with foreground extinction. The resulting 10‐μm absorption profiles are remarkably similar to those of the field star Taurus‐Elias 16 obtained by Bowey, Adamson & Whittet. The fitted temperature indices are 0.44 (HL Tau) and 0.33 (Elias 7) in agreement with Boss's theoretical models of the 200–300 K region, but lower than those of IR–submm discs (0.5–0.61; Mannings & Emerson); a significant fraction of the modelled 10‐μm emission of HL Tau is optically thin, whilst that of Elias 7 is optically thick. We suggest that HL Tau's optically thin component arises from silicate dust within low‐density layers above an optically thick disc.