Time Variability of the Dust Sublimation Zones in Pre-Main Sequence Disk Systems

Details Time Variability of the Dust Sublimation Zones in Pre-Main Sequence Disk Systems Time Variability of the Dust Sublimation Zones in Pre-Main Sequence Disk Systems

Oct 2007

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007dps....39.4201s&link_type=abstract

American Astronomical Society, DPS meeting #39, #42.01; Bulletin of the American Astronomical Society, Vol. 39, p.495

Other

Scientific paper

The dust sublimation zone (DSZ) is the region of pre-main sequence (PMS) disks where dust grains most easily anneal, sublime, and condense out of the gas. Thus the DSZ is a location where crystalline material may be enhanced and redistributed throughout the rest of the disk. A decade-long program to monitor the thermal emission of the grains located in this region demonstrates that large changes in emitted flux occur in many systems.
We have observed variability in the thermal emission between 3 and 13.5 microns in HD 31648 (MWC 480), HD 163296 (MWC 275), and DG Tau that are consistent with structural changes DSZ, where the transition from a disk of gas to one of gas+dust occurs. In the case of DG Tau, one photometric outburst observed between 3-5 microns was accompanied by increased emission of the 10 micron silicate band. During another similar outburst the silicate band went into absorption. These changes require lofting of the material above the disk into the line of sight. Such variability will affect the determination of the inner disk structure obtained through interferometry measurements, and changes in fringe visibility have recently been confirmed in the case of HD 163296.
Cyclic variations in the heating of the DSZ will lead to the annealing of large grains, the sublimation of smaller grains, possibly followed by re-condensation as the zone enters a cooling phase. Lofting of dust above the disk plane, and outward acceleration by stellar winds and radiation pressure, can re-distribute the processed material to cooler regions of the disk, where cometesimals form. This processing is consistent with the detection of the preferential concentration of large crystalline grains in the inner few AU of PMS disks using interferometric spectroscopy with the VLTI.

Affiliated with

Also associated with

No associations

Rating

Time Variability of the Dust Sublimation Zones in Pre-Main Sequence Disk Systems 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 Time Variability of the Dust Sublimation Zones in Pre-Main Sequence Disk Systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Time Variability of the Dust Sublimation Zones in Pre-Main Sequence Disk Systems will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1066563