VALES I: the molecular gas content in star-forming dusty H-ATLAS galaxies up to z = 0.35

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.
Referencia bibliográfica

Monthly Notices of the Royal Astronomical Society, Volume 470, Issue 4, p.3775-3805

Fecha de publicación:
10
2017
Número de autores
27
Número de autores del IAC
1
Número de citas
31
Número de citas referidas
29
Descripción
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.
Proyectos relacionados
Proto-cúmulo de galaxias
Gas Molecular y Polvo en Galacias através del Tiempo Cósmico
Dos cuestiones fundamentales en la Astrofísica son la conversión de gas molecuar en estrellas y cómo este proceso físico depende del entorno en todas las escalas, desde sistemas planetarios, cúmulos estelares, galaxias hasta cúmulos de galaxias. El objectivo principal de este proyecto es el de estudiar la formación y evolución de galaxias a partir
Helmut
Dannerbauer