Properties of galaxies at the faint end of the H[alpha] luminosity function at z~ 0.62

Context. Studies measuring the star formation rate density, luminosity function, and properties of star-forming galaxies are numerous. However, it exists a gap at 0.5 < z< 0.8 in H[alpha]-based studies. Aims. Our main goal is to study the properties of a sample of faint H[alpha] emitters at z~...

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Bibliographic Details
Published in:Astronomy and astrophysics (Berlin) 2016-07, Vol.591
Main Authors: Gomez-Guijarro, Carlos, Gallego, Jesus, Villar, Victor, Rodriguez-Munoz, Lucia, Clement, Benjamin, Cuby, Jean-Gabriel
Format: Article
Language:English
Subjects:
Compact galaxies
Density
Extinction
Galaxies
Luminosity
Morphology
Star formation
Star formation rate
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Summary:Context. Studies measuring the star formation rate density, luminosity function, and properties of star-forming galaxies are numerous. However, it exists a gap at 0.5 < z< 0.8 in H[alpha]-based studies. Aims. Our main goal is to study the properties of a sample of faint H[alpha] emitters at z~ 0.62. We focus on their contribution to the faint end of the luminosity function and derived star formation rate density, characterising their morphologies and basic photometric and spectroscopic properties. Methods. We use a narrow-band technique in the near-infrared, with a filter centred at 1.06[mu] m. The data come from ultra-deep VLT/HAWK-I observations in the GOODS-S field with a total of 31.9h in the narrow-band filter. In addition to our survey, we mainly make use of ancillary data coming from the CANDELS and Rainbow Cosmological Surveys Database, from the 3D-HST for comparison, and also spectra from the literature. We perform a visual classification of the sample and study their morphologies from structural parameters available in CANDELS. In order to obtain the luminosity function, we apply a traditional V/V sub(max) method and perform individual extinction corrections for each object to accurately trace the shape of the function. Results. Our 28 H[alpha]-selected sample of faint star-forming galaxies reveals a robust faint-end slope of the luminosity function [alpha] = - 1.46 sub(-0.08) super(+0.16). The derived star formation rate density at z~ 0.62 is [rho] sub(SFR)= 0.036 sub(-0.008) super(+0.012) M sub([middot in circle]) yr super(-1) Mpc super(-3). The sample is mainly composed of disks, but an important contribution of compact galaxies with Sersic indexes n~ 2 display the highest specific star formation rates. Conclusions. The luminosity function at z~ 0.62 from our ultra-deep data points towards a steeper [alpha] when an individual extinction correction for each object is applied. Compact galaxies are low-mass, low-luminosity, and starburst-dominated objects with a light profile in an intermediate stage from early to late types.
ISSN:0004-6361
1432-0746
DOI:10.1051/0004-6361/201526746