Spitzer Space Telescope - General Observer Proposal #3416


Shock Dissipation in Nearby Star Forming Regions

Principal Investigator: John Bally
           Institution: University of Colorado, Boulder

Co-Investigators: 
Josh Walawender, University of Colorado                               
Bo Reipurth, IFA, University of Hawaii                                
Dirk Froebrich, Dublin Institute for Advanced Studies                 
Michael Smith, Armagh Observatory                                     

Science Category: ISM 
 Observing Modes: IrsMap 
  Hours Approved: 10.0 

Abstract:
We propose to probe the line emission from nearby star forming regions
in the 5 to 37 micron spectral range using the slit-scan mode of IRS.
Our goals are:  [1] Measure the fluxes produced by the pure rotational
lines of molecular hydrogen and other spectral features in the 5 to 38
micrometer region from the surroundings of 4 well-studied and nearby
outflow sources.  [2] Trace the intermediate velocity (2 to 30
km/sec) shocks in outflow regions.  Such emission is predicted by
models in which high velocity motions traced by optical and near-IR
emission lines (Herbig-Haro objects) accelerate molecular outflows and
degrade into turbulent motions.  We will obtain slit-scan maps in the
LL and SL modes of IRS of arc-minute scale regions surrounding HH 211,
HH212, L1448c and, NGC 2071.  By observing these four sources, we will
compare the mid-IR emission lines produced by regions supporting
various levels of star formation activity ranging from the birth of
isolated single stars, to small groups, to rich clusters containing
over 100  YSOs and stars as massive as 8 to 10  Solar masses.