Talk abstract
Herschel view of gas and dust in protoplanetary disks
Abstract
Primordial protoplanetary discs consist 99% out of gas, and only 1% out of dust, but the gas phase remained difficult to observe so far.
Herschel offers a unique opportunity to probe the warm atomic and molecular layers of discs, from low mass T Tauri stars to intermediate and high mass Herbig~Ae/Be stars.
We present the first results of fine structure line emission and photometry
from the Herschel Open Time Key Program GASPS (Gas in Protoplanetary Systems), which is observing a sample of 250 discs, concentrating on emission lines of [OI], [CII], H20 and CO. These observations are interpreted in light of a grid of 300\,000 models combining state-of-the-art radiative transfer and chemical codes. The first results of the GASPS survey indicates the main gas heating mechanisms as a function of the spectral type of the central object and offers insights on the relative evolution of the dust and gas phases in dics.
We will also illustrate how the combination of Herschel line observations with continuum data and/or with rotational lines in the (sub-)millimetre regime, in particular CO lines, is required for a detailed characterisation of the physical and
chemical properties of young stellar objects.
Herschel offers a unique opportunity to probe the warm atomic and molecular layers of discs, from low mass T Tauri stars to intermediate and high mass Herbig~Ae/Be stars.
We present the first results of fine structure line emission and photometry
from the Herschel Open Time Key Program GASPS (Gas in Protoplanetary Systems), which is observing a sample of 250 discs, concentrating on emission lines of [OI], [CII], H20 and CO. These observations are interpreted in light of a grid of 300\,000 models combining state-of-the-art radiative transfer and chemical codes. The first results of the GASPS survey indicates the main gas heating mechanisms as a function of the spectral type of the central object and offers insights on the relative evolution of the dust and gas phases in dics.
We will also illustrate how the combination of Herschel line observations with continuum data and/or with rotational lines in the (sub-)millimetre regime, in particular CO lines, is required for a detailed characterisation of the physical and
chemical properties of young stellar objects.