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Title: EVIDENCE FOR LOW EXTINCTION IN ACTIVELY STAR-FORMING GALAXIES AT z > 6.5

Abstract

We present a search for the [C II] 158 {mu}m fine structure line (a main cooling line of the interstellar medium) and the underlying far-infrared (FIR) continuum in three high-redshift (6.6 < z < 8.2) star-forming galaxies using the IRAM Plateau de Bure Interferometer. We targeted two Ly{alpha}-selected galaxies (Ly{alpha} emitters, LAEs) with moderate UV-based star formation rates (SFRs {approx} 20 M{sub Sun} yr{sup -1}; Himiko at z = 6.6 and IOK-1 at z = 7.0) and a gamma-ray burst (GRB) host galaxy (GRB 090423 at z {approx} 8.2). Based on our 3{sigma} rest-frame FIR continuum limits, previous (rest-frame) UV continuum measurements and spectral energy distribution (SED) fitting, we rule out SED shapes similar to highly obscured galaxies (e.g., Arp 220, M 82) and less extreme dust-rich nearby spiral galaxies (e.g., M 51) for the LAEs. Conservatively assuming an SED shape typical of local spiral galaxies we derive upper limits for the FIR-based star formation rates (SFRs) of {approx}70 M{sub Sun} yr{sup -1}, {approx}50 M{sub Sun} yr{sup -1}, and {approx}40 M{sub Sun} yr{sup -1} for Himiko, IOK-1, and GRB 090423, respectively. For the LAEs these limits are only a factor {approx}3 higher than the published UV-based SFRs (uncorrected for extinction).more » This indicates that the dust obscuration in the z > 6 LAEs studied here is lower by a factor of a few than what has recently been found in some LAEs at lower redshift (2 < z < 3.5) with similar UV-based SFRs. A low obscuration in our z > 6 LAE sample is consistent with recent rest-frame UV studies of z {approx} 7 Lyman break galaxies.« less

Authors:
;  [1];  [2];  [3];  [4];  [5]; ;  [6];  [7];  [8];  [9];  [10]
  1. Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)
  2. National Radio Astronomy Observatory, 1003 Lopezville Road, Socorro, NM 87801 (United States)
  3. Astronomy Department, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125 (United States)
  4. Argelander-Institut fuer Astronomie, Auf dem Huegel 71, D-53121 Bonn (Germany)
  5. Max-Planck-Insitut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany)
  6. Institut de Radio Astronomie Millimetrique (IRAM), F-38406, St. Martin d'Heres (France)
  7. Institute of Astronomy, Cavendish Laboratory, University of Cambridge, 19 JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)
  8. Observational Cosmology Group, University of Tokyo, ICRR, 5-1-5 Kashiwanoha, Kashiwa 277-0882 (Japan)
  9. Department of Astronomy/Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065 (United States)
  10. ALMA Project Office, National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
Publication Date:
OSTI Identifier:
22037050
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; ASTROPHYSICS; COSMIC DUST; COSMIC GAMMA BURSTS; COSMOLOGY; ENERGY SPECTRA; FINE STRUCTURE; GALACTIC EVOLUTION; GALAXIES; GAMMA ASTRONOMY; INFRARED RADIATION; INTERFEROMETERS; INTERSTELLAR SPACE; RED SHIFT; STARS

Citation Formats

Walter, F., Decarli, R., Carilli, C., Riechers, D., Bertoldi, F., Weiss, A., Cox, P., Neri, R., Maiolino, R., Ouchi, M., Egami, E., and Nakanishi, K., E-mail: walter@mpia.de. EVIDENCE FOR LOW EXTINCTION IN ACTIVELY STAR-FORMING GALAXIES AT z > 6.5. United States: N. p., 2012. Web. doi:10.1088/0004-637X/752/2/93.
Walter, F., Decarli, R., Carilli, C., Riechers, D., Bertoldi, F., Weiss, A., Cox, P., Neri, R., Maiolino, R., Ouchi, M., Egami, E., & Nakanishi, K., E-mail: walter@mpia.de. EVIDENCE FOR LOW EXTINCTION IN ACTIVELY STAR-FORMING GALAXIES AT z > 6.5. United States. doi:10.1088/0004-637X/752/2/93.
Walter, F., Decarli, R., Carilli, C., Riechers, D., Bertoldi, F., Weiss, A., Cox, P., Neri, R., Maiolino, R., Ouchi, M., Egami, E., and Nakanishi, K., E-mail: walter@mpia.de. Wed . "EVIDENCE FOR LOW EXTINCTION IN ACTIVELY STAR-FORMING GALAXIES AT z > 6.5". United States. doi:10.1088/0004-637X/752/2/93.
@article{osti_22037050,
title = {EVIDENCE FOR LOW EXTINCTION IN ACTIVELY STAR-FORMING GALAXIES AT z > 6.5},
author = {Walter, F. and Decarli, R. and Carilli, C. and Riechers, D. and Bertoldi, F. and Weiss, A. and Cox, P. and Neri, R. and Maiolino, R. and Ouchi, M. and Egami, E. and Nakanishi, K., E-mail: walter@mpia.de},
abstractNote = {We present a search for the [C II] 158 {mu}m fine structure line (a main cooling line of the interstellar medium) and the underlying far-infrared (FIR) continuum in three high-redshift (6.6 < z < 8.2) star-forming galaxies using the IRAM Plateau de Bure Interferometer. We targeted two Ly{alpha}-selected galaxies (Ly{alpha} emitters, LAEs) with moderate UV-based star formation rates (SFRs {approx} 20 M{sub Sun} yr{sup -1}; Himiko at z = 6.6 and IOK-1 at z = 7.0) and a gamma-ray burst (GRB) host galaxy (GRB 090423 at z {approx} 8.2). Based on our 3{sigma} rest-frame FIR continuum limits, previous (rest-frame) UV continuum measurements and spectral energy distribution (SED) fitting, we rule out SED shapes similar to highly obscured galaxies (e.g., Arp 220, M 82) and less extreme dust-rich nearby spiral galaxies (e.g., M 51) for the LAEs. Conservatively assuming an SED shape typical of local spiral galaxies we derive upper limits for the FIR-based star formation rates (SFRs) of {approx}70 M{sub Sun} yr{sup -1}, {approx}50 M{sub Sun} yr{sup -1}, and {approx}40 M{sub Sun} yr{sup -1} for Himiko, IOK-1, and GRB 090423, respectively. For the LAEs these limits are only a factor {approx}3 higher than the published UV-based SFRs (uncorrected for extinction). This indicates that the dust obscuration in the z > 6 LAEs studied here is lower by a factor of a few than what has recently been found in some LAEs at lower redshift (2 < z < 3.5) with similar UV-based SFRs. A low obscuration in our z > 6 LAE sample is consistent with recent rest-frame UV studies of z {approx} 7 Lyman break galaxies.},
doi = {10.1088/0004-637X/752/2/93},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 752,
place = {United States},
year = {2012},
month = {6}
}