Extragalactic abstracts - IRSA - California Institute of Technology
Extragalactic abstracts - IRSA - California Institute of Technology
Extragalactic abstracts - IRSA - California Institute of Technology
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Spitzer_Approved_<strong>Extragalactic</strong><br />
Mar 25, 10 16:24 Page 501/742<br />
Spitzer Space Telescope − General Observer Proposal #30634<br />
Two Types <strong>of</strong> Type−2?<br />
Principal Investigator: Alejo Martinez−Sansigre<br />
Institution: Oxford University<br />
Technical Contact: Alejo Martinez−Sansigre, Oxford University<br />
Co−Investigators:<br />
Steve Rawlings, Oxford University<br />
Lacy Mark, Spitzer Science Center<br />
Chris Simpson, Durham University<br />
Chris Willott, Herzerg Institure <strong>of</strong> Astrophysics<br />
Jarvis Matt, Oxford University<br />
Francine Marleau, Spitzer Science Center<br />
Dario Fadda, Spitzer Science Center<br />
Science Category: AGN/quasars/radio galaxies<br />
Observing Modes: IrsStare<br />
Hours Approved: 22.8<br />
Abstract:<br />
We propose to use the Spitzer IRS instrument to test the hypothesis that there<br />
are two distinct types <strong>of</strong> Type−2 (obscured) QSO: the first in which the nucleus<br />
is obscured at optical wavelengths by an organized torus; and the second, in<br />
which the nucleus is obscured by more distributed dust in an associated<br />
starburst. We will target a complete sample <strong>of</strong> Type−2 QSOs at z = 1.4−2 from the<br />
Spitzer First−Look Survey which, from optical spectroscopy, split into objects<br />
with high excitation, narrow−emission lines (torus−obscured QSOs?) and objects<br />
with totally blank optical spectra (starburst−obscured QSOs?). The IRS spectra<br />
will be sensitive to the the ‘Silicate Break’ (and PAH features) and therefore<br />
identify and provide redshifts for any starburst−obscured QSOs, whereas QSOs in<br />
which there is a clear view <strong>of</strong> hot dust in the torus, will have relatively<br />
featureless mid−IR spectra, except for the silicate absorption feature.<br />
Spitzer_Approved_<strong>Extragalactic</strong><br />
Printed_by_SSC<br />
Mar 25, 10 16:24 Page 502/742<br />
Spitzer Space Telescope − General Observer Proposal #40517<br />
Infrared SEDs and dust emission from z > 5 quasars. Part I. Probing the hottest<br />
dust with Spitzer.<br />
Principal Investigator: Klaus Meisenheimer<br />
Institution: Max−Planck−Institut fuer Astronomie<br />
Technical Contact: Helmut Dannerbauer, Max−Planck−Institut fuer Astronomie<br />
Co−Investigators:<br />
Helmut Dannerbauer, MPIA<br />
Fabian Walter, MPIA<br />
Xiaohui Fan, University <strong>of</strong> Arizona<br />
Linhua Jiang, University <strong>of</strong> Arizona<br />
Oliver Krause, MPIA<br />
Ulrich Klaas, MPIA<br />
Science Category: AGN/quasars/radio galaxies<br />
Observing Modes: IracMap MipsPhot<br />
Hours Approved: 71.1<br />
Abstract:<br />
As part <strong>of</strong> a comprehensive multi−wavelength project to determine the Spectral<br />
Energy Distributions (SEDs) <strong>of</strong> all known quasars at z > 5, we propose Spitzer<br />
photometry in the four IRAC bands and the MIPS 24 um band. These observations<br />
are the necessary short wavelengths complement to our Herschel guaranteed time<br />
Key Project, which will measure the Far−IR SED <strong>of</strong> 77 quasars at z > 5 in the<br />
range 70 to 170 um (PACS) and 240 to 520 um (SPIRE). In addition, our target<br />
list contains 17 radio−loud quasars and galaxies at z > 3.5. The combined<br />
Spitzer plus Herschel photometry will characterize the overall Mid− to<br />
Far−infrared SEDs <strong>of</strong> a large sample <strong>of</strong> quasars at the highest redshifts in great<br />
detail and thus provide a data base <strong>of</strong> huge legacy value. We selected all those<br />
targets for this Spitzer proposal for which IRAC and MIPS photometry are neither<br />
observed nor scheduled. The proposed observations will cover rest−frame<br />
wavelengths between 0.5 and 4 um which will allow us to detect the hottest dust<br />
as an excess <strong>of</strong> the measured 24 um flux (above the UV−optical continuum as<br />
derived from the IRAC bands and NIR photometry). Our observations will enlarge<br />
the present samples <strong>of</strong> z > 5 quasars with Mid−IR photometry by a factor <strong>of</strong> 4.<br />
This will allow us to determine the frequency <strong>of</strong> peculiar (dust−free ?) objects<br />
detected in previous studies and to carry out statistical investigations <strong>of</strong> the<br />
relation between UV−optical spectrum from the accretion disk and the emission<br />
from the hottest part <strong>of</strong> the dust torus.<br />
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