Spectro-astrometric imaging of molecular gas within protoplanetary disk gaps

Details Spectro-astrometric imaging of molecular gas within protoplanetary disk gaps Spectro-astrometric imaging of molecular gas within protoplanetary disk gaps

2008-05-21

arxiv.org/abs/0805.3314v1

Astronomy and Astrophysics

Astrophysics

7 pages, accepted for publication in ApJ

Scientific paper

10.1086/590400

We present velocity-resolved spectro-astrometric imaging of the 4.7 $\mu$m rovibrational lines of CO gas in protoplanetary disks using the CRIRES high resolution infrared spectrometer on the Very Large Telescope (VLT). The method as applied to three disks with known dust gaps or inner holes out to 4-45 AU (SR 21, HD 135344B and TW Hya) achieves an unprecedented spatial resolution of $0.1-0.5$ AU. While one possible gap formation mechanism is dynamical clearing by giant planets, other equally good explanations (stellar companions, grain growth, photo-evaporation) exist. One way of distinguishing between different scenarios is the presence and distribution of gas inside the dust gaps. Keplerian disk models are fit to the spectro-astrometric position-velocity curves to derive geometrical parameters of the molecular gas. We determine the position angles and inclinations of the inner disks with accuracies as good as 1-2\degr, as well as the radial extent of the gas emission. Molecular gas is detected well inside the dust gaps in all three disks. The gas emission extends to within a radius of 0.5 AU for HD 135344B and to 0.1 AU for TW Hya, supporting partial clearing by a $< 1-10 M_{\rm Jup}$ planetary body as the cause of the observed dust gaps, or removal of the dust by extensive grain coagulation and planetesimal formation. The molecular gas emission in SR 21 appears to be truncated within $\sim 7 $AU, which may be caused by complete dynamical clearing by a more massive companion. We find a smaller inclination angle of the inner disk of TW Hya than that determined for the outer disk, suggestive of a disk warp. We also detect significant azimuthal asymmetries in the SR 21 and HD 135344B inner disks.

Affiliated with

Also associated with

No associations

Rating

Spectro-astrometric imaging of molecular gas within protoplanetary disk gaps 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 Spectro-astrometric imaging of molecular gas within protoplanetary disk gaps, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spectro-astrometric imaging of molecular gas within protoplanetary disk gaps will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-290489