Astronomy and Astrophysics – Astrophysics – Earth and Planetary Astrophysics
Scientific paper
2011-03-15
Astronomy and Astrophysics
Astrophysics
Earth and Planetary Astrophysics
Accepted for publication in the Astrophysical Journal
Scientific paper
We present a spectro-astrometric survey of molecular gas in the inner regions of 16 protoplanetary disks using CRIRES, the high resolution infrared imaging spectrometer on the Very Large Telescope. Spectro-astrometry with CRIRES measures the spatial extent of line emission to sub-milliarcsecond precision, or <0.2 AU at the distance of the observed targets. The sample consists of gas-rich disks surrounding stars with spectral types ranging from K to A. The properties of the spectro-astrometric signals divide the sources into two distinct phenomenological classes: one that shows clear Keplerian astrometric spectra, and one in which the astrometric signatures are dominated by gas with strong non-Keplerian (radial) motions. Similarly to the near-infrared continuum emission, as determined by interferometry, we find that the size of the CO line emitting region in the Keplerian sources obeys a size-luminosity relation as $R_CO L_*^0.5. The non-Keplerian spectro-astrometric signatures are likely indicative of the presence of wide-angle disk winds. The central feature of the winds is a strong sub-Keplerian velocity field due to conservation of angular momentum as the wind pressure drives the gas outwards. We construct a parametrized 2-dimensional disk+wind model that reproduces the observed characteristics the observed CO spectra and astrometry. The modeled winds indicate mass-loss rates of >10^-10 to 10^-8 Msol/yr. We suggest a unifying model in which all disks have slow molecular winds, but where the magnitude of the mass-loss rate determines the degree to which the mid-infrared molecular lines are dominated by the wind relative to the Keplerian disk surface.
Blake Geoffrey A.
Pontoppidan Klaus Martin
Smette Alain
No associations
LandOfFree
The structure and dynamics of molecular gas in planet-forming zones: A CRIRES spectro-astrometric survey does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The structure and dynamics of molecular gas in planet-forming zones: A CRIRES spectro-astrometric survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The structure and dynamics of molecular gas in planet-forming zones: A CRIRES spectro-astrometric survey will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-139489