NOAO > Observing Info > Approved Programs > 2012B-0465
|
NOAO > Observing Info > Approved Programs > 2012B-0465 |
|
PI: Susan Ridgway, NOAO, ser@noao.edu
Address: PO Box 26732, 950 North Cherry Avenue, Tucson, AZ 85726-6732, USA
CoI: Mark Lacy, NRAO Headquarters
CoI: Andreea Petric, Caltech
CoI: Anna Sajina, Tufts
CoI: Tanya Urrutia, AIP, Potsdam
CoI: Duncan Farrah, Sussex
Title: The Evolution of the Obscured and Unobscured Quasar Population
Abstract:
We will use GMOS-S to obtain spectra of luminous AGN and quasars selected in
the mid-infrared. Mid-infrared selection is much less biased with respect to
obscuration than optical and X-ray techniques, and hence allows for finding
obscured (Type-2) quasars as well as Type-1 quasars. Our survey so far has
been very successful and has provided an unique opportunity to construct
luminosity functions for both Type-1 and Type-2 quasars selected in the same
way and covering similar redshifts and luminosities. We have begun accurately
quantifying the change in the obscured fraction with luminosity and redshift
for the first time, and find interesting indications that at high redshift
the obscured fraction rises, consistent with models for the joint formation
of the galaxy and black hole populations. Our samples are, however, quite
incomplete at low luminosities (and therefore high redshift), particularly in
the southern hemisphere. By bringing these southern samples to a reasonable
completeness level, we will greatly increase the number of high z quasars in
our sample, allowing us to better judge our tantalizing initial results on
the redshift evolution of the obscured fraction. In addition, these southern
targets can be followed up with ALMA and GEMS/GSAOI to study the morphologies
and star-formation properties of the hosts, allowing further exploration of
the relationship between the formation of massive bulges and supermassive
blackholes in the early universe.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
|
NOAO > Observing Info > Approved Programs > 2012B-0465 |
|