Bibcode
Villanueva, V.; Ibar, E.; Hughes, T. M.; Lara-López, M. A.; Dunne, L.; Eales, S.; Ivison, R. J.; Aravena, M.; Baes, M.; Bourne, N.; Cassata, P.; Cooray, A.; Dannerbauer, H.; Davies, L. J. M.; Driver, S. P.; Dye, S.; Furlanetto, C.; Herrera-Camus, R.; Maddox, S. J.; Michałowski, M. J.; Molina, J.; Riechers, D.; Sansom, A. E.; Smith, M. W. L.; Rodighiero, G.; Valiante, E.; van der Werf, P.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 470, Issue 4, p.3775-3805
Advertised on:
10
2017
Citations
29
Refereed citations
27
Description
We present an extragalactic survey using observations from the Atacama
Large Millimeter/submillimeter Array (ALMA) to characterize galaxy
populations up to z = 0.35: the Valparaíso ALMA Line Emission
Survey (VALES). We use ALMA Band-3 CO(1-0) observations to study the
molecular gas content in a sample of 67 dusty normal star-forming
galaxies selected from the Herschel Astrophysical Terahertz Large Area
Survey (H-ATLAS). We have spectrally detected 49 galaxies at
>5σ significance and 12 others are seen at low significance in
stacked spectra. CO luminosities are in the range of (0.03-1.31) ×
1010 K km s-1 pc2, equivalent to log
({M}_{gas}/M_{⊙}) =8.9 - 10.9 assuming an αCO = 4.6
(K km s-1 pc2)-1, which perfectly
complements the parameter space previously explored with local and
high-z normal galaxies. We compute the optical to CO size ratio for 21
galaxies resolved by ALMA at ˜3.5 arcsec resolution (6.5 kpc),
finding that the molecular gas is on average ˜ 0.6 times more
compact than the stellar component. We obtain a global Schmidt-Kennicutt
relation, given by log [Σ _SFR/(M_{⊙} yr^{-1} kpc^{-2})]
=(1.26 ± 0.02) × log [Σ _{{M}_{H2}}/(M_{⊙}
pc^{-2})] - (3.6 ± 0.2). We find a significant fraction of
galaxies lying at `intermediate efficiencies' between a long-standing
mode of star formation activity and a starburst, specially at
LIR = 1011-12 L⊙. Combining our
observations with data taken from the literature, we propose that star
formation efficiencies can be parametrized by log [{SFR/{M}_{H_2}}] =
0.19 × {(log {L_{IR}} - 11.45)}-8.26- 0.41 × arctan [-4.84
(log {{L}_{IR}}-11.45) ]. Within the redshift range we explore (z <
0.35), we identify a rapid increase of the gas content as a function of
redshift.
Related projects
Molecular Gas and Dust in Galaxies Across Cosmic Time
Two of the most fundamental questions in astrophysics are the conversion of molecular gas into stars and how this physical process is a function of environments on all scales, ranging from planetary systems, stellar clusters, galaxies to galaxy clusters. The main goal of this internal project is to get insight into the formation and evolution of
Helmut
Dannerbauer