Spitzer Space Telescope - General Observer Proposal #20302


A Spitzer imaging study of a selected sample of prestellar cores

Principal Investigator: Philippe Andre
           Institution: CEA Saclay

Co-Investigators: 
Nicolas Peretto, CEA Saclay, France                                   
Aurore Bacmann, Observatoire de Bordeaux, France                      
Jeroen Bouwman, MPIA Heidelberg, Germany                              
Derek Ward-Thompson, Cardiff University, UK                           
Kengo Tachihara, Astrophysical Institute, Jena, Germany               
Toshikazu Onishi, Nagoya University, Japan                            

Science Category: young stellar objects 
 Observing Modes: IracMap MipsScan 
  Hours Approved: 26.5 

Abstract:
We propose a dedicated imaging study with both IRAC and MIPS of six
nearby prestellar cores spanning a range of environmental conditions.
These cores, which have previously been mapped at 7 microns with
ISOCAM and/or 1.3mm with the IRAM 30m telescope, are believed to be
representative of the initial conditions for protostellar collapse.
Some of them apparently feature sharp outer edges, possibly
corresponding to a dramatic change in the thermal properties of the
gas/dust at the interfaces with the ambient cloud.  We expect these
starless cores to be seen absorption with IRAC at 3.6-8 microns and
MIPS at 24 microns and in emission with MIPS at 160  microns.  Our
proposed multi-wavelength imaging with Spitzer will allow us to obtain
unique constraints on their outer temperature structure and on the
physical nature of their apparently sharp interfaces with their parent
clouds.  The improved resolution of IRAC over ISOCAM will also allow
us to probe, for the first time, the small-scale structure of these
objects (and possible sub-fragmentation into multiple systems).