Naslov
Discs and haloes in pre-main-sequence stars

Autori
Vinković, Dejan ; Ivezić, Željko ; Miroshnichenko, Anatoly S. ; Elitzur, Moshe

Izvornik
Monthly Notices of the Royal Astronomical Society (0035-8711) 346 (2003), 4; 1151-1161

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
radiative transfer – circumstellar matter – stars: formation – stars: imaging – stars: pre-main-sequence – dust; extinction

Sažetak
We study the infrared (IR) emission from flared discs with and without additional optically thin haloes. Flux calculations of a flared disc in vacuum can be considered a special case of the more general family of models in which the disc is imbedded in an optically thin halo. In the absence of such a halo, flux measurements can never rule out its existence because the disc flaring surface defines a mathematically equivalent halo that produces the exact same flux at all IR wavelengths. When a flared disc with height H at its outer radius R is imbedded in a halo whose optical depth at visual wavelengths is τ halo, the system IR flux is dominated by the halo whenever τ halo > (1/4)H/R. Even when its optical depth is much smaller, the halo can still have a significant effect on the disc temperature profile. Imaging is the only way to rule out the existence of a potential halo, and we identify a decisive test that extracts a signature unique to flared discs from imaging observations.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Informacijske i komunikacijske znanosti

POVEZANOST RADA