Spitzer Space Telescope - Snapshot Proposal #80069


Old Stellar Populations of The VGS Void Galaxies

Principal Investigator: Burcu Beygu
           Institution: Kapteyn Astronomical Institute, Groningen

     Technical Contact: Thomas Jarrett, California Institute of Technology

Co-Investigators: 
Tom Jarrett, IPAC                                                     
Rien van de Weygaert, Kapteyn Institute                               
Kathryn Kreckel, Columbia University                                  
Thijs van der Hulst, Kapteyn Institute                                
Jacqueline van Gorkom, Columbia University                            

Science Category: nearby galaxies (z<0.05, v_sys<15,000 km/s) 
  Hours Approved: 14.0 

Abstract:
Cosmic voids form an essential ingredient of the Cosmic Web and may harbour a
systematically different population of galaxies. Largely unaffected by the
complex processes modifying galaxies in high-density environments, the pristine
and isolated void regions must hold important clues to the intrinsic process of
formation and evolution of galaxies. The Void Galaxy Survey (VGS) is a
multi-wavelength program to study 60 void galaxies. Each has been selected from
the deepest interior regions of identified voids in the SDSS redshift survey on
the basis of a unique geometric technique, with no a prior selection of
intrinsic properties of the void galaxies. The project intends to study in
detail the gas content, star formation history and stellar content, as well as
kinematics and dynamics of void galaxies and their companions in a broad sample
of void environments. It involves the HI imaging of the gas distribution in each
of the VGS galaxies. Amongst its most tantalizing findings is the possible
evidence for cold gas accretion in some of the most interesting objects, amongst
which are a polar ring galaxy and a filamentary configuration of void galaxies.
An essential aspect for understanding the formation and evolution of void
galaxies concerns their star formation history. The current IRAC proposal is
meant to study the older stellar population of void galaxies to constrain their
assembly history.