NRAO/Socorro Colloquium Series

Raghvendra Sahai

JPL


The Extraordinary Deaths of Ordinary Stars: Jets, Water-Fountains and Dusty Disks


The biggest challenge in the study of the evolution of low and intermediate mass stars beyond the Asymptotic Giant Branch (AGB) is understanding the origin of the remarkable morphological and kinematical differences between AGB circumstellar envelopes and their more evolved counterparts, Pre-Planetary and Planetary Nebulae (PPNe and PNe). Based on the results of an unbiased survey of young PN morphologies with HST, we hypothesized in 1998 that high-speed jets, which become operational during or just after the AGB phase, are the primary agent for producing PN morphologies. In this talk, I will discuss our studies of pre-planetary nebulae which support this hypothesis. In particular, I will focus on our recent interferometric observations at millimeter and radio wavelengths of the jets and central dusty disks/torii in these objects.




March 23, 2007
11:00 a.m. MT

Array Operations Center Auditorium

All NRAO employees are invited to attend via video, available in Charlottesville Room 230, Green Bank Room 137 and Tucson 525.

Local Host: Mark Claussen