THE MOLECULAR GAS CONTENT OF z = 3 LYMAN BREAK GALAXIES: EVIDENCE OF A NON-EVOLVING GAS FRACTION IN MAIN-SEQUENCE GALAXIES AT z > 2

Journal Article · Wed Oct 10 00:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/758/1/L9· OSTI ID:22078510

Magdis, Georgios E; Rigopoulou, D ^[1]; Daddi, E; Sargent, M; Elbaz, D; Gobat, R; Tan, Q; Aussel, H ^[2]; Dannerbauer, H ^[3]; Feruglio, C ^[4]; Charmandaris, V ^[5]; Dickinson, M ^[6]; Reddy, N ^[7]

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1. Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom)
2. CEA, Laboratoire AIM, Irfu/SAp, F-91191 Gif-sur-Yvette (France)
3. Institut fuer Astronophysik, Universitaet Wien, Tuerkenschanzstrasse 17, A-1180 Wien (Austria)
4. IRAM-Institut de RadioAstronomie Millimetrique 300 rue de la Piscine, Domaine Universitaire, F-38406 Saint Martin d'Heres (France)
5. Department of Physics and Institute of Theoretical and Computational Physics, University of Crete, GR-71003 Heraklion (Greece)
6. NOAO, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States)
7. Department of Physics and Astronomy, University of California, Riverside 900 University, Avenue Riverside, CA 92507 (United States)

We present observations of the CO[J = 3 {yields} 2] emission toward two massive and infrared luminous Lyman break galaxies (LBGs) at z = 3.21 and z = 2.92, using the IRAM Plateau de Bure Interferometer, placing first constraints on the molecular gas masses (M{sub gas}) of non-lensed LBGs. Their overall properties are consistent with those of typical (main-sequence) galaxies at their redshifts, with specific star formation rates {approx}1.6 and {approx}2.2 Gyr{sup -1}, despite their large infrared luminosities (L{sub IR} Almost-Equal-To (2-3) Multiplication-Sign 10{sup 12} L{sub Sun }) derived from Herschel. With one plausible CO detection (spurious detection probability of 10{sup -3}) and one upper limit, we investigate the evolution of the molecular gas-to-stellar mass ratio (M{sub gas}/M{sub *}) with redshift. Our data suggest that the steep evolution of M{sub gas}/M{sub *} of normal galaxies up to z {approx} 2 is followed by a flattening at higher redshifts, providing supporting evidence for the existence of a plateau in the evolution of the specific star formation rate at z > 2.5.

• OSTI ID: 22078510
• Journal Information: Astrophysical Journal Letters, Vol. 758, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CARBON MONOXIDE
EMISSION
GALAXIES
INTERFEROMETERS
LUMINOSITY
MASS
MOLECULES
RED SHIFT