Previous | Session 39 | Next | Author Index | Block Schedule
J. Williams, S. Andrews (IfA, University of Hawaii)
We present the results of a recent submillimeter survey of protostellar disks in the Taurus star forming cloud. Carried out using the SCUBA and SHARC cameras on the James Clerk Maxwell Telescope and Caltech Submillimeter Observatory, respectively, our survey is about a factor of 5 more sensitive than previous work. We are therefore able to follow disk evolution to systematically lower masses and later times. We show the mass distribution from young, accreting disks (Class I) through intermediate (Class II) to late stage, passive disks (Class III) and demonstrate that the cool, outer regions (> 5 AU) apparently disappear on timescales comparable to the ~5 Myr inner disk lifetime inferred from infrared observations. Possible scenarios for the synchronization of inner and outer disk disappearance and the implications for planet, or at least, planetesimal formation, are discussed.
For the brighter (Class I/II) disks, we were also able to measure the spectral energy distribution at 350 and 450 microns. This provides important new constraints on the dust grain opacity and its evolution as a disk ages. We show that the frequency dependence of the opacity becomes shallower with time. This is indicative of grain agglomeration and is a key signature of the first steps toward planet formation.
If you would like more information about this abstract, please follow the link to http://xxx.lanl.gov/abs/astro-ph/0506187. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.
Previous | Session 39 | Next
Bulletin of the American Astronomical Society, 37 #4
© 2005. The American Astronomical Soceity.