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 5/742<br />
Spitzer Space Telescope − General Observer Proposal #3680<br />
Ejecta and Interstellar Dust in Magellanic Clouds Supernova Remnants<br />
Principal Investigator: Kazimierz Borkowski<br />
Institution: North Carolina State University<br />
Technical Contact: Kazimierz Borkowski, North Carolina State University<br />
Co−Investigators:<br />
William Blair, Johns Hopkins University<br />
Parviz Ghavamian, Johns Hopkins University<br />
Sean Hendrick, North Carolina State University<br />
Knox Long, Space Science Telescope <strong>Institute</strong><br />
John Raymond, Harvard University<br />
Stephen Reynolds, North Carolina State University<br />
Ravi Sankrit, Johns Hopkins University<br />
Chris Smith, National Optical Astronomy Observatory<br />
Frank Winkler, Middlebury College<br />
Science Category: local group galaxies<br />
Observing Modes: IracMap MipsPhot<br />
Hours Approved: 21.4<br />
Abstract:<br />
Stellar explosions govern the interstellar dust lifecycle. In the early<br />
Universe, supernovae (SN) injected the first heavy elements into the<br />
interstellar medium (ISM). A significant fraction <strong>of</strong> ejecta was dust. Dust is<br />
destroyed today in supernova remnant’s (SNR) blast waves. Our current<br />
understanding <strong>of</strong> both formation <strong>of</strong> dust in SNe and destruction <strong>of</strong> dust in blast<br />
waves is poorly understood. We propose to observe a complete sample <strong>of</strong> SNRs in<br />
Magellanic Clouds (MCs) with the Spitzer Space Telescope (SST) in order to<br />
dramatically advance our knowledge <strong>of</strong> these processes. Heavy−element ejecta have<br />
been detected in more than one third <strong>of</strong> all SNRs in MCs, mostly in X−rays. Dust<br />
within these ejecta is collisionally heated by electrons and ions, and<br />
reradiates the absorbed energy in the far−IR. We propose deep MIPS and IRAC<br />
imaging <strong>of</strong> all MC SNRs with heavy−element ejecta in order to detect and study<br />
ejecta dust. We will determine dust temperature, dust mass, and its spatial<br />
distribution within ejecta. We will also detect dust in the ISM swept by SNR<br />
blast waves. This dust is destroyed by sputtering in hot X−ray emitting plasmas.<br />
We will learn about dust destruction by measuring the dust/gas mass ratio behind<br />
blast waves through a combined IR−X−ray analysis. Sputtering preferentially<br />
destroys small dust grains, modifying the grain size distribution. This strongly<br />
affects thermal dust emission in the IRAC bands which is produced by small<br />
grains. We will learn about the destruction <strong>of</strong> small grains by observing spatial<br />
variations <strong>of</strong> IRAC band ratios behind blast waves. An unbiased survey <strong>of</strong> all<br />
SNRs in MCs is necessary for understanding <strong>of</strong> dust destruction. We propose 24<br />
micron MIPS imaging <strong>of</strong> all MC SNRs, and 70 micron MIPS imaging <strong>of</strong> X−ray bright<br />
SNRs. The proposed MIPS and IRAC imaging <strong>of</strong> MC SNRs will provide us with unique<br />
information about ejecta dust in a large sample <strong>of</strong> SNRs and about destruction <strong>of</strong><br />
the ISM dust.<br />
Spitzer_Approved_<strong>Extragalactic</strong><br />
Printed_by_SSC<br />
Mar 25, 10 16:24 Page 6/742<br />
Spitzer Space Telescope − Archive Research Proposal #40568<br />
Star Clusters in M31: Stellar Populations and Mass Loss<br />
Principal Investigator: Jean Brodie<br />
Institution: University <strong>of</strong> <strong>California</strong>, Santa Cruz<br />
Technical Contact: Jean Brodie, University <strong>of</strong> <strong>California</strong>, Santa Cruz<br />
Co−Investigators:<br />
Jay Strader, University <strong>of</strong> <strong>California</strong>, Santa Cruz<br />
Jacco van Loon, Keele University<br />
Science Category: local group galaxies<br />
Dollars Approved: 48294.0<br />
Abstract:<br />
We propose an imaging study <strong>of</strong> massive star clusters in M31 using archival<br />
Spitzer imaging with IRAC and MIPS. We have two distinct goals: (1) Estimate<br />
cluster ages, metallicities, and reddenings through panchromatic FUV to mid−IR<br />
imaging, and (2) Assess the production rate and lifetime <strong>of</strong> dust in the<br />
intracluster medium (ICM) as a function <strong>of</strong> cluster properties. Our results will<br />
give important constraints on the star formation history <strong>of</strong> M31 and on mass loss<br />
in stellar clusters.<br />
Thursday March 25, 2010 xgal_covers.txt<br />
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