Spitzer Space Telescope - General Observer Proposal #40002


The Structure and Evolution of Stellar Wind-Blown Dust Bubbles

Principal Investigator: Edward Churchwell
           Institution: University of Wisconsin, Madison

     Technical Contact: Edward Churchwell, University of Wisconsin, Madison

Co-Investigators: 
Mark Wolfire, University of Maryland                                  
Christer Watson, Manchester College                                   
Barbara Whitney, Space Science Institute                              

Science Category: HII regions 
 Observing Modes: IrsMap 
  Hours Approved: 19.5 

Abstract:
We propose to obtain partial spectral line images, using Spitzer/IRS, of four
carefully selected Galactic infrared bubbles (detected in the GLIMPSE survey)
that have different morphologies and are believed to represent different stages
of evolution. The main goals of this program are to: test and constrain
dynamical evolution models of bubbles produced by young O-stars. Temperature,
density, and velocity structure are predicted to change by orders of magnitude
with age and with radius from the central star(s). Confirmation of these
predictions has had limited success because of limitations imposed by
extinction, sensitivity, spatial resolution, and access to probes that sample a
wide range of ionization. IRS is ideally suited to detect and measure the radii
of the various ionization zones and transition regions within stellar wind-blown
bubbles. We propose to do this by obtaining spectral line images of a strip
across the diameter of the four selected bubbles.