Spitzer Space Telescope - Snapshot Proposal #80093


Sensitive Spitzer Photometry of Supermassive Black Holes at the Final Stage of
Adolescence

Principal Investigator: Ohad Shemmer
           Institution: University of North Texas

     Technical Contact: Ohad Shemmer, University of North Texas

Co-Investigators: 
Hagai Netzer, Tel Aviv University                                     
Rivay Mor, Tel Aviv University                                        
Benny Trakhtenbrot, Tel Aviv University                               

Science Category: AGN/quasars/radio galaxies 
  Hours Approved: 10.9 

Abstract:
We propose to obtain sensitive Spitzer snapshot observations of a unique sample
of 35 Sloan Digital Sky Survey quasars at redshift 4.8 for which we obtained
reliable, Mg II-based determinations of the supermassive black hole (SMBH) mass
and normalized accretion rate (L/L_Edd). These quasars appear to mark the final
stage of SMBH `adolescence' in the history of the Universe as their SMBHs are
significantly less massive and their L/L_Edd values are significantly higher
with respect to their counterparts at lower redshifts. Our observations will
provide both 1) deep coverage of the fields around these quasars which will be
utilized as crucial priors for our approved Herschel/SPIRE observations of these
sources, and 2) coverage of the rest-frame optical SEDs of these fast accreting
quasars. The results will maximize our ability to measure the star-formation
rate in the host galaxies of these quasars using Herschel. We will thus be able
to investigate correlations between SMBH growth and star-forming activity in the
early Universe. The Spitzer photometry will also provide invaluable information
about the shape of the rest-frame optical continuum in these quasars which will
be used to search for extreme disk properties that may be signatures of the
remarkably high accretion rates in these sources.