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Title: CONVERTING FROM 3.6 AND 4.5 {mu}m FLUXES TO STELLAR MASS

Abstract

We use high spatial resolution maps of stellar mass and infrared flux of the Large Magellanic Cloud (LMC) to calibrate a conversion between 3.6 and 4.5 {mu}m fluxes and stellar mass, M{sub *} = 10{sup 5.65} F{sup 2.85}{sub 3.6} F{sup -1.85}{sub 4.5}(D/0.05){sup 2} M{sub Sun }, where fluxes are in Jy and D is the luminosity distance to the source in Mpc, and to provide an approximate empirical estimate of the fractional internal uncertainty in M{sub *} of 0.3{radical}(N/10{sup 6}), where N is the number of stars in the region. We find evidence that young stars and hot dust contaminate the measurements, but attempts to remove this contamination using data that are far superior to what are generally available for unresolved galaxies resulted in marginal gains in accuracy. The scatter among mass estimates for regions in the LMC is comparable to that found by previous investigators when modeling composite populations, and so we conclude that our simple conversion is as precise as possible for the data and models currently available. Our results allow for a reasonably bottom-heavy initial mass function, such as Salpeter or heavier, and moderately disfavor lighter versions such as a diet-Salpeter or Chabrier initial mass function.

Authors:
 [1];  [2];  [3]
  1. Department of Astronomy, University of Texas, Austin, TX 78712 (United States)
  2. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
  3. Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)
Publication Date:
OSTI Identifier:
22034448
Resource Type:
Journal Article
Journal Name:
Astronomical Journal (New York, N.Y. Online)
Additional Journal Information:
Journal Volume: 143; Journal Issue: 6; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1538-3881
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; APPROXIMATIONS; ASTRONOMY; ASTROPHYSICS; COMPUTERIZED SIMULATION; CONVERSION; DISTANCE; DUSTS; LUMINOSITY; MAGELLANIC CLOUDS; MASS; SPATIAL RESOLUTION; STARS

Citation Formats

Eskew, Michael, Zaritsky, Dennis, and Meidt, Sharon, E-mail: meskew@astro.as.utexas.edu, E-mail: dzaritsky@as.arizona.edu, E-mail: meidt@mpia.de. CONVERTING FROM 3.6 AND 4.5 {mu}m FLUXES TO STELLAR MASS. United States: N. p., 2012. Web. doi:10.1088/0004-6256/143/6/139.
Eskew, Michael, Zaritsky, Dennis, & Meidt, Sharon, E-mail: meskew@astro.as.utexas.edu, E-mail: dzaritsky@as.arizona.edu, E-mail: meidt@mpia.de. CONVERTING FROM 3.6 AND 4.5 {mu}m FLUXES TO STELLAR MASS. United States. doi:10.1088/0004-6256/143/6/139.
Eskew, Michael, Zaritsky, Dennis, and Meidt, Sharon, E-mail: meskew@astro.as.utexas.edu, E-mail: dzaritsky@as.arizona.edu, E-mail: meidt@mpia.de. Fri . "CONVERTING FROM 3.6 AND 4.5 {mu}m FLUXES TO STELLAR MASS". United States. doi:10.1088/0004-6256/143/6/139.
@article{osti_22034448,
title = {CONVERTING FROM 3.6 AND 4.5 {mu}m FLUXES TO STELLAR MASS},
author = {Eskew, Michael and Zaritsky, Dennis and Meidt, Sharon, E-mail: meskew@astro.as.utexas.edu, E-mail: dzaritsky@as.arizona.edu, E-mail: meidt@mpia.de},
abstractNote = {We use high spatial resolution maps of stellar mass and infrared flux of the Large Magellanic Cloud (LMC) to calibrate a conversion between 3.6 and 4.5 {mu}m fluxes and stellar mass, M{sub *} = 10{sup 5.65} F{sup 2.85}{sub 3.6} F{sup -1.85}{sub 4.5}(D/0.05){sup 2} M{sub Sun }, where fluxes are in Jy and D is the luminosity distance to the source in Mpc, and to provide an approximate empirical estimate of the fractional internal uncertainty in M{sub *} of 0.3{radical}(N/10{sup 6}), where N is the number of stars in the region. We find evidence that young stars and hot dust contaminate the measurements, but attempts to remove this contamination using data that are far superior to what are generally available for unresolved galaxies resulted in marginal gains in accuracy. The scatter among mass estimates for regions in the LMC is comparable to that found by previous investigators when modeling composite populations, and so we conclude that our simple conversion is as precise as possible for the data and models currently available. Our results allow for a reasonably bottom-heavy initial mass function, such as Salpeter or heavier, and moderately disfavor lighter versions such as a diet-Salpeter or Chabrier initial mass function.},
doi = {10.1088/0004-6256/143/6/139},
journal = {Astronomical Journal (New York, N.Y. Online)},
issn = {1538-3881},
number = 6,
volume = 143,
place = {United States},
year = {2012},
month = {6}
}