Spitzer Space Telescope - General Observer Proposal #30299


An intensive Spitzer survey of FeLoBAL QSOs

Principal Investigator: Duncan Farrah
           Institution: Cornell University

Co-Investigators: 
Colin Borys, University of Toronto                                    
Robert Priddey, University of Hertfordshire                           
Jose Afonso, University of Lisbon                                     
Mark Lacy, Spitzer Science Center                                     

Science Category: AGN/quasars/radio galaxies 
 Observing Modes: MipsPhot 
  Hours Approved: 9.9 

Abstract:
We propose MIPS and IRS observations of eight 'FeLoBAL' quasars.
These quasars are characterised by absorption from metastable excited
states of iron in their UV spectra, and are currently thought to be
extremely rare, with only 40  examples known over the whole sky.  Very
recent observations have however suggested that FeLoBALs are
potentially quite common, and that they may represent a critical point
in the lifetime of an IR-luminous galaxy when an obscured starburst is
approaching its end, and a youthful quasar is starting to emerge from
its dust cocoon.  In this proposal, we aim to use Spitzer to test this
hypothesis.  We will use the MIPS data to see if FeLoBALs as a class
are preferentially associated with heavily obscured starbursts, and
use the IRS spectra to see if the mid-IR emission from FeLoBALs is
consistent with an evolutionary sequence from ULIRG to FeLoBAL,
through to optical QSO.