Spitzer Space Telescope - Guaranteed Time Observer Proposal #40374


Do FeLoBALs mark the transition between a ULIRG and a QSO?

Principal Investigator: Duncan Farrah
           Institution: Cornell University

     Technical Contact: Duncan Farrah, Cornell University

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

Science Category: AGN/quasars/radio galaxies 
 Observing Modes: IrsStare 
  Hours Approved: 14.0 

Abstract:
We propose deep IRS observations of six Spitzer/MIPS detected 'FeLoBAL' quasars.
These quasars are characterised by iron absorption in their UV spectra. Once
thought to be extremely rare, recent observations have however suggested that
FeLoBALs may be common, and might 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. We have used Spitzer
to observe seven FeLoBAL QSOs, and found that all seven are bright in the IR,
and likely contain both luminous, dusty AGN and intense, obscured star
formation. We here seek to use IRS to observe six of these QSOs, to determine
whether or not FeLoBALs are a transition type object via direct comparison
between their mid-IR spectra and those of ULIRGs and QSOs.