Extragalactic abstracts - IRSA - California Institute of Technology
Extragalactic abstracts - IRSA - California Institute of Technology
Extragalactic abstracts - IRSA - California Institute of Technology
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Spitzer_Approved_<strong>Extragalactic</strong><br />
Mar 25, 10 16:24 Page 677/742<br />
Spitzer Space Telescope − Guaranteed Time Observer Proposal #50323<br />
IR spectra, star formation rates, and metallicities in submillimeter galaxies<br />
Principal Investigator: George Rieke<br />
Institution: The University <strong>of</strong> Arizona<br />
Technical Contact: Benjamin Weiner, Steward Observatory, U. Arizona<br />
Co−Investigators:<br />
Benjamin Weiner, Steward Observatory<br />
Eiichi Egami, Steward Observatory<br />
Delphine Marcillac, Steward Observatory<br />
Casey Papovich, Steward Observatory<br />
Christopher Willmer, Steward Observatory<br />
Jane Rigby, Carnegie Observatories<br />
Almudena Alonso−Herrero, Instituto de Estructura de la Materia<br />
Chad Engelbracht, Steward Observatory<br />
Science Category: ULIRGS/LIRGS/HLIRGS<br />
Observing Modes: IrsMap MipsPhot<br />
Hours Approved: 8.2<br />
Abstract:<br />
Sub−millimeter continuum observations probe the long−wavelength side <strong>of</strong> far−IR<br />
dust emission from distant galaxies, detecting cold dust and dusty galaxies at<br />
higher redshifts. This makes the sub−mm uniquely sensitive to types <strong>of</strong> dusty<br />
galaxies that are disfavored by shorter−wavelength selection, such as at 24<br />
microns. However, for the same reason, only a relatively small number <strong>of</strong> sub−mm<br />
galaxies have high−quality Spitzer/IRS spectra. We propose to obtain IRS spectra<br />
<strong>of</strong> a carefully selected sample <strong>of</strong> 7 galaxies with sub−mm detections, firm radio<br />
and infrared cross−IDs and positions, sufficient 24 micron flux, and in several<br />
cases, detections at 70 and even 160 microns. These galaxies are in fields with<br />
deep IRAC and MIPS photometry and sensitive multiwavelength coverage from X−ray<br />
to radio. The IRS spectra will determine the restframe mid−IR PAH emission,<br />
silicate absorption, and continuum shape. These features along with far−IR dust<br />
temperatures and multiwavelength data will enable us to construct SEDs for cool,<br />
dusty galaxies at z ~ 0.5−2, and to determine whether the properties <strong>of</strong> such<br />
galaxies are similar to local unusually cool ULIRGs (e.g. Arp 220) or have<br />
evolved with redshift. We are also proposing to take deep IRS exposures to<br />
measure Brackett alpha, [Ne II] and [Ne III] mid−IR lines in 3 <strong>of</strong> the galaxies.<br />
These lines yield measurements <strong>of</strong> star formation rate and metallicity that are<br />
unaffected by extinction. We will test whether IR−luminous galaxies at z~1 are<br />
lower metallicity than local examples, and whether metallicity evolution is<br />
affecting far−IR estimates <strong>of</strong> star formation rate.<br />
Spitzer_Approved_<strong>Extragalactic</strong><br />
Printed_by_SSC<br />
Mar 25, 10 16:24 Page 678/742<br />
Spitzer Space Telescope − Guaranteed Time Observer Proposal #50324<br />
IR spectra, star formation rates, and metallicities in submillimeter galaxies<br />
Principal Investigator: George Rieke<br />
Institution: The University <strong>of</strong> Arizona<br />
Technical Contact: Benjamin Weiner, Steward Observatory, U. Arizona<br />
Co−Investigators:<br />
Benjamin Weiner, Steward Observatory<br />
Eiichi Egami, Steward Observatory<br />
Delphine Marcillac, Steward Observatory<br />
Casey Papovich, Steward Observatory<br />
Christopher Willmer, Steward Observatory<br />
Jane Rigby, Carnegie Observatories<br />
Almudena Alonso−Herrero, Instituto de Estructura de la Materia<br />
Chad Engelbracht, Steward Observatory<br />
Science Category: ULIRGS/LIRGS/HLIRGS<br />
Observing Modes:<br />
Hours Approved: 33.9<br />
Abstract:<br />
Sub−millimeter continuum observations probe the long−wavelength side <strong>of</strong> far−IR<br />
dust emission from distant galaxies, detecting cold dust and dusty galaxies at<br />
higher redshifts. This makes the sub−mm uniquely sensitive to types <strong>of</strong> dusty<br />
galaxies that are disfavored by shorter−wavelength selection, such as at 24<br />
microns. However, for the same reason, only a relatively small number <strong>of</strong> sub−mm<br />
galaxies have high−quality Spitzer/IRS spectra. We propose to obtain IRS spectra<br />
<strong>of</strong> a carefully selected sample <strong>of</strong> 7 galaxies with sub−mm detections, firm radio<br />
and infrared cross−IDs and positions, sufficient 24 micron flux, and in several<br />
cases, detections at 70 and even 160 microns. These galaxies are in fields with<br />
deep IRAC and MIPS photometry and sensitive multiwavelength coverage from X−ray<br />
to radio. The IRS spectra will determine the restframe mid−IR PAH emission,<br />
silicate absorption, and continuum shape. These features along with far−IR dust<br />
temperatures and multiwavelength data will enable us to construct SEDs for cool,<br />
dusty galaxies at z ~ 0.5−2, and to determine whether the properties <strong>of</strong> such<br />
galaxies are similar to local unusually cool ULIRGs (e.g. Arp 220) or have<br />
evolved with redshift. We are also proposing to take deep IRS exposures to<br />
measure Brackett alpha, [Ne II] and [Ne III] mid−IR lines in 3 <strong>of</strong> the galaxies.<br />
These lines yield measurements <strong>of</strong> star formation rate and metallicity that are<br />
unaffected by extinction. We will test whether IR−luminous galaxies at z~1 are<br />
lower metallicity than local examples, and whether metallicity evolution is<br />
affecting far−IR estimates <strong>of</strong> star formation rate. This is part 2 <strong>of</strong> program<br />
50323.<br />
Thursday March 25, 2010 xgal_covers.txt<br />
339/371