Spitzer Space Telescope - Archive Research Proposal #50668


An archival Spitzer study of protostars

Principal Investigator: Lee Hartmann
           Institution: University of Michigan

     Technical Contact: Lee Hartmann, University of Michigan

Co-Investigators: 
Nuria Calvet, University of Michigan                                  
John Tobin, University of Michigan                                    
Elise Furlan, UCLA                                                    

Science Category: young stellar objects 
Dollars Approved: 75000 

Abstract:
We propose to use spatially-resolved imaging and spectroscopic data from
Spitzer, combined with longer-wavelength studies, to develop a comprehensive
picture of protostellar envelopes for a sample of young stellar objects.
Radiative transfer modeling will allow us to explore the following questions:
Do infalling envelopes generally form inner toroids in addition to more
flattened disks, as predicted by some models with strong magnetic fields? Are
most protostellar disks bright in the IRAC range, indicating rapid disk
accretion in early stellar evolution? Do envelopes generally have high-albedo,
i.e., larger grains? What is the nature of the interface between the infalling
envelope and the cavity-producing outflow? The sample of protostars to be
studied will enable us to examine whether envelope properties depend upon
protostellar luminosity and/or environment. Our models will also have long-term
utility, in that we will make predictions for future sub-mm and mm-wave
interferometric observations constraining envelope chemistry, kinematics, and
outflow-inflow interactions. This study will provide fundamental insights into
protostellar collapse in particular and star formation in general.