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Title: DUST-TO-GAS RATIO IN THE EXTREMELY METAL-POOR GALAXY I Zw 18

Abstract

The blue compact dwarf galaxy I Zw 18 is one of the most metal-poor systems known in the local universe (12+log(O/H) = 7.17). In this work we study I Zw 18 using data from Spitzer, Herschel Space Telescope, and IRAM Plateau de Bure Interferometer. Our data set includes the most sensitive maps of I Zw 18, to date, in both the far-infrared and the CO J = 1 {yields} 0 transition. We use dust emission models to derive a dust mass upper limit of only M{sub dust} {<=} 1.1 Multiplication-Sign 10{sup 4} M{sub Sun} (3{sigma} limit). This upper limit is driven by the non-detection at 160 {mu}m, and it is a factor of 4-10 times smaller than previous estimates (depending on the model used). We also estimate an upper limit to the total dust-to-gas mass ratio of M{sub Dust}/M{sub gas} {<=} 5.0 Multiplication-Sign 10{sup -5}. If a linear correlation between the dust-to-gas mass ratio and metallicity (measured as O/H) were to hold, we would expect a ratio of 3.9 Multiplication-Sign 10{sup -4}. We also show that the infrared spectral energy distribution is similar to that of starbursting systems.

Authors:
; ;  [1];  [2];  [3]; ;  [4]; ;  [5];  [6]
  1. Department of Astronomy and Laboratory of Millimeter Astronomy, University of Maryland, College Park, MD 20742 (United States)
  2. National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States)
  3. Max-Planck-Institut fuer Astronomie, Konigstuehl 17, D-69117 Heidelberg (Germany)
  4. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
  5. Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)
  6. Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States)
Publication Date:
OSTI Identifier:
22037018
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 752; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; CARBON MONOXIDE; CORRELATIONS; COSMIC DUST; DETECTION; EMISSION; ENERGY SPECTRA; GALAXIES; INTERFEROMETERS; MASS; METALS; UNIVERSE

Citation Formats

Herrera-Camus, Rodrigo, Fisher, David B., Bolatto, Alberto D., Leroy, Adam K., Walter, Fabian, Gordon, Karl D., Roman-Duval, Julia, Donaldson, Jessica, Melendez, Marcio, and Cannon, John M. DUST-TO-GAS RATIO IN THE EXTREMELY METAL-POOR GALAXY I Zw 18. United States: N. p., 2012. Web. doi:10.1088/0004-637X/752/2/112.
Herrera-Camus, Rodrigo, Fisher, David B., Bolatto, Alberto D., Leroy, Adam K., Walter, Fabian, Gordon, Karl D., Roman-Duval, Julia, Donaldson, Jessica, Melendez, Marcio, & Cannon, John M. DUST-TO-GAS RATIO IN THE EXTREMELY METAL-POOR GALAXY I Zw 18. United States. doi:10.1088/0004-637X/752/2/112.
Herrera-Camus, Rodrigo, Fisher, David B., Bolatto, Alberto D., Leroy, Adam K., Walter, Fabian, Gordon, Karl D., Roman-Duval, Julia, Donaldson, Jessica, Melendez, Marcio, and Cannon, John M. Wed . "DUST-TO-GAS RATIO IN THE EXTREMELY METAL-POOR GALAXY I Zw 18". United States. doi:10.1088/0004-637X/752/2/112.
@article{osti_22037018,
title = {DUST-TO-GAS RATIO IN THE EXTREMELY METAL-POOR GALAXY I Zw 18},
author = {Herrera-Camus, Rodrigo and Fisher, David B. and Bolatto, Alberto D. and Leroy, Adam K. and Walter, Fabian and Gordon, Karl D. and Roman-Duval, Julia and Donaldson, Jessica and Melendez, Marcio and Cannon, John M.},
abstractNote = {The blue compact dwarf galaxy I Zw 18 is one of the most metal-poor systems known in the local universe (12+log(O/H) = 7.17). In this work we study I Zw 18 using data from Spitzer, Herschel Space Telescope, and IRAM Plateau de Bure Interferometer. Our data set includes the most sensitive maps of I Zw 18, to date, in both the far-infrared and the CO J = 1 {yields} 0 transition. We use dust emission models to derive a dust mass upper limit of only M{sub dust} {<=} 1.1 Multiplication-Sign 10{sup 4} M{sub Sun} (3{sigma} limit). This upper limit is driven by the non-detection at 160 {mu}m, and it is a factor of 4-10 times smaller than previous estimates (depending on the model used). We also estimate an upper limit to the total dust-to-gas mass ratio of M{sub Dust}/M{sub gas} {<=} 5.0 Multiplication-Sign 10{sup -5}. If a linear correlation between the dust-to-gas mass ratio and metallicity (measured as O/H) were to hold, we would expect a ratio of 3.9 Multiplication-Sign 10{sup -4}. We also show that the infrared spectral energy distribution is similar to that of starbursting systems.},
doi = {10.1088/0004-637X/752/2/112},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 752,
place = {United States},
year = {2012},
month = {6}
}