Irradiation of Accretion Disks Around Young Objects. I. Near Infrared CO Bands; Calvet n et al 1991

Miércoles, 17 de Abril de 1991 19:30

Authors:		Calvet, Nuria; Patino, Alberto; Magris, Gladis C.; D'Alessio, Paola
Affiliation:		AA(Centro de Investigaciones de Astronomia, Merida, Venezuela; Institut d'Estudis Catalans, Barcelona, Spain), AB(Centro de Investigaciones de Astronomia; Universidad de los Andes, Merida, Venezuela), AC(Centro de Investigaciones de Astronomia, Merida; Universidad Central de Venezuela, Caracas), AD(Universidad Nacional Autonoma de Mexico, Coyoacan, Mexico; Centro de Investigaciones de Astronomia, Merida, Venezuela)
Publication:		Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 380, Oct. 20, 1991, p. 617-630. Research supported by Universidad de los Andes and Smithsonian Institution. (ApJ Homepage)
Publication Date:		10/1991
Category:		Astrophysics
Origin:		STI
NASA/STI Keywords:		ACCRETION DISKS, CARBON MONOXIDE, NEAR INFRARED RADIATION, RADIATIVE TRANSFER, STELLAR ATMOSPHERES, A STARS, B STARS, COMPUTATIONAL ASTROPHYSICS, STELLAR MASS ACCRETION, STELLAR TEMPERATURE, T TAURI STARS
DOI:		10.1086/170618
Bibliographic Code:		1991ApJ...380..617C

Abstract

The effect of irradiation by the central star on the atmospheres of optically thick physically thin accretion disks around young objects are approximated, assuming radiative equilibrium. Irradiation is found to increase the temperature in the atmosphere of a viscous accretion disk relative to the case when only the viscous flux goes through it. Its effect on the near-infrared spectrum of the star-disk configuration is to decrease the strength of the absorption in the CO bands or turn them into emission, depending on the irradiation rate and on the mass accretion rate. As the stellar effect temperature increases for a given mass accretion rate, the disk surface temperature increases and the CO bands turn into emission. Observed spectra of young objects such as T Tauri stars, FU Ori subjects, and Herbig Be/Ae stars are in qualitative agreement with those predicted using the corresponding stellar parameters and disk mass accretion rates. It is inferred that the near-infrared CO bands can be used as indicators of the rate of mass accretion in the disk around young objects.

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