Spitzer Space Telescope - General Observer Proposal #3437


Disk Evolution in the Orion OB1 Association

Principal Investigator: Nuria Calvet
           Institution: University of Michigan

Co-Investigators: 
James Muzerolle, Steward Observatory                                  
Cesar Briceno, CIDA                                                   
Lee Hartmann, Smithsonian Astrophysical Observatory                   
Paola D'Alessio, Instituto de Astronomia UNAM                         

Science Category: circumstellar/debris disks 
 Observing Modes: IracMap MipsScan 
  Hours Approved: 11.0 

Abstract:
We propose to conduct a comprehensive study of circumstellar disk
emission in the Orion OB1 association using all the instruments on the
Spitzer Space Telescope.  The Orion OB1 association offers a unique
laboratory for understanding disk structure and evolution in a
distributed population of low mass young stars over an age range of
1-10  Myr.  The pre-main sequence population spread out over 100
square degrees in this region has been well-characterized by our group
via an extensive ground-based optical survey.  IRAC and MIPS maps of
two representative regions with different ages will allow us to study
complete spectral energy distributions out to 24 microns, diagnosing
the structure of circumstellar disks from the strength and shape of
the excess infrared continuum emission.  Additional IRS spectra of a
small sample of objects with existing ground-based mid-IR detections
will provide more detailed information about the dust content of the
disks.  In combination with detailed modeling, the data will provide
key insights into the processes affecting disk evolution in a
non-clustered environment with nearby massive stars, including effects
such as dust settling and inside-out clearing which are critical
influences on planet formation.