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Title: EXPANDED VERY LARGE ARRAY OBSERVATIONS OF A PROTO-CLUSTER OF MOLECULAR GAS-RICH GALAXIES AT z = 4.05

Abstract

We present observations of the molecular gas in the GN20 proto-cluster of galaxies at z = 4.05 using the Expanded Very Large Array (EVLA). This group of galaxies is the ideal laboratory for studying the formation of massive galaxies via luminous, gas-rich starbursts within 1.6 Gyr of the big bang. We detect three galaxies in the proto-cluster in CO 2-1 emission, with gas masses (H{sub 2}) between 10{sup 10} and 10{sup 11} x ({alpha}/0.8) M{sub sun}. The emission from the brightest source, GN20, is resolved with a size {approx}2'' and has a clear north-south velocity gradient, possibly indicating ordered rotation. The gas mass in GN20 is comparable to the stellar mass (1.3 x 10{sup 11} x ({alpha}/0.8) M{sub sun} and 2.3 x 10{sup 11} M{sub sun}, respectively), and the sum of gas plus stellar mass is comparable to the dynamical mass of the system ({approx}3.4 x 10{sup 11}[sin (i)/sin (45{sup 0})]{sup -2} M{sub sun}), within a 5 kpc radius. There is also evidence for a tidal tail extending another 2'' north of the galaxy with a narrow velocity dispersion. GN20 may be a massive, gas-rich disk that is gravitationally disturbed, but not completely disrupted. There is one Lyman-break galaxy (BD29079)more » in the GN20 proto-cluster with an optical spectroscopic redshift within our search volume, and we set a 3{sigma} limit to the molecular gas mass of this galaxy of 1.1 x 10{sup 10} x ({alpha}/0.8) M{sub sun}.« less

Authors:
 [1]; ; ;  [2];  [3];  [4];  [5]
  1. National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801-0387 (United States)
  2. Max-Planck Institute for Astronomy, Konigstuhl 17, 69117, Heidelberg (Germany)
  3. Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
  4. Laboratoire AIM, CEA/DSM-CNRS-University Paris Diderot, DAPNIA/Service Astrophysccique, CEA Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette (France)
  5. Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)
Publication Date:
OSTI Identifier:
21565468
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 739; Journal Issue: 1; Other Information: DOI: 10.1088/2041-8205/739/1/L33; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CARBON MONOXIDE; EMISSION; EVOLUTION; GALAXIES; GALAXY CLUSTERS; HYDROGEN; MASS; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; ELEMENTS; NONMETALS; OXIDES; OXYGEN COMPOUNDS

Citation Formats

Carilli, C. L., Hodge, J., Walter, F., Dannerbauer, H., Riechers, D., Daddi, E., and Morrison, G. E. EXPANDED VERY LARGE ARRAY OBSERVATIONS OF A PROTO-CLUSTER OF MOLECULAR GAS-RICH GALAXIES AT z = 4.05. United States: N. p., 2011. Web. doi:10.1088/2041-8205/739/1/L33.
Carilli, C. L., Hodge, J., Walter, F., Dannerbauer, H., Riechers, D., Daddi, E., & Morrison, G. E. EXPANDED VERY LARGE ARRAY OBSERVATIONS OF A PROTO-CLUSTER OF MOLECULAR GAS-RICH GALAXIES AT z = 4.05. United States. doi:10.1088/2041-8205/739/1/L33.
Carilli, C. L., Hodge, J., Walter, F., Dannerbauer, H., Riechers, D., Daddi, E., and Morrison, G. E. Tue . "EXPANDED VERY LARGE ARRAY OBSERVATIONS OF A PROTO-CLUSTER OF MOLECULAR GAS-RICH GALAXIES AT z = 4.05". United States. doi:10.1088/2041-8205/739/1/L33.
@article{osti_21565468,
title = {EXPANDED VERY LARGE ARRAY OBSERVATIONS OF A PROTO-CLUSTER OF MOLECULAR GAS-RICH GALAXIES AT z = 4.05},
author = {Carilli, C. L. and Hodge, J. and Walter, F. and Dannerbauer, H. and Riechers, D. and Daddi, E. and Morrison, G. E.},
abstractNote = {We present observations of the molecular gas in the GN20 proto-cluster of galaxies at z = 4.05 using the Expanded Very Large Array (EVLA). This group of galaxies is the ideal laboratory for studying the formation of massive galaxies via luminous, gas-rich starbursts within 1.6 Gyr of the big bang. We detect three galaxies in the proto-cluster in CO 2-1 emission, with gas masses (H{sub 2}) between 10{sup 10} and 10{sup 11} x ({alpha}/0.8) M{sub sun}. The emission from the brightest source, GN20, is resolved with a size {approx}2'' and has a clear north-south velocity gradient, possibly indicating ordered rotation. The gas mass in GN20 is comparable to the stellar mass (1.3 x 10{sup 11} x ({alpha}/0.8) M{sub sun} and 2.3 x 10{sup 11} M{sub sun}, respectively), and the sum of gas plus stellar mass is comparable to the dynamical mass of the system ({approx}3.4 x 10{sup 11}[sin (i)/sin (45{sup 0})]{sup -2} M{sub sun}), within a 5 kpc radius. There is also evidence for a tidal tail extending another 2'' north of the galaxy with a narrow velocity dispersion. GN20 may be a massive, gas-rich disk that is gravitationally disturbed, but not completely disrupted. There is one Lyman-break galaxy (BD29079) in the GN20 proto-cluster with an optical spectroscopic redshift within our search volume, and we set a 3{sigma} limit to the molecular gas mass of this galaxy of 1.1 x 10{sup 10} x ({alpha}/0.8) M{sub sun}.},
doi = {10.1088/2041-8205/739/1/L33},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 739,
place = {United States},
year = {2011},
month = {9}
}