Spitzer Space Telescope - Archive Research Proposal #50077


Spitzer characterization of dust grains in regions of anomalous emission

Principal Investigator: Roberta Paladini
           Institution: Spitzer Science Center

     Technical Contact: Roberta Paladini, Spitzer Science Center

Co-Investigators: 
Clive Dickinson, IPAC/Caltech                                         
Simon Casassus, University of Chile                                   
Kieran Cleary, Jet Propulsionary Laboratory                           
Alberto Noriega-Crespo, Spitzer Science Center                        
Sean Carey, Spitzer Science Center                                    
Nicolas Flagey, Spitzer Science Center                                
Francine Marleau, Spitzer Science Center                              
Sachindev Shenoy, Spitzer Science Center                              

Science Category: ISM 
Dollars Approved: 50000 

Abstract:
Despite the increasing evidence that the anomalous emission is a new physical
mechanism acting in the diffuse interstellar medium, the nature and distribution
of this component remains elusive. In particular, the infrared properties of the
sources which, to date, are known to exhibit microwave excess, are very poorly
known mostly due to the limited angular resolution and frequency coverage of
DIRBE and IRAS. We propose to analyze archival observations of anomalous
emission regions in order to characterize the typical dust population and
environment, in particular the grain size, grain constituents and radiation
field hardness, in these regions. A search in the Spitzer archive has revealed
that almost the entirety of the objects with signatures of anomalous emission
have been observed by its instruments. In addition, Spitzer data, with their
unique combination of high resolution, sensitivity and wide spectral coverage,
provide a unique tool for investigating the physical properties of dust in these
sources. Such characterization will allow to put tight constraints on the
existing models and provide new predictions on the level of contamination
expected in future CMB experiments.