2017MNRAS.465.2717P -
Mon. Not. R. Astron. Soc., 465, 2717-2733 (2017/March-1)
The structural and size evolution of star-forming galaxies over the last 11 Gyr.
PAULINO-AFONSO A., SOBRAL D., BUITRAGO F. and AFONSO J.
Abstract (from CDS):
We present new results on the evolution of rest-frame blue/UV sizes and Sersic indices of Hα-selected star-forming galaxies over the last 11 Gyr. We investigate how the perceived evolution can be affected by a range of biases and systematics such as cosmological dimming and resolution effects. We use GALFIT and an artificial redshifting technique, which includes the luminosity evolution of Hα-selected galaxies, to quantify the change on the measured structural parameters with redshift. We find typical sizes of 2-3 kpc and Sersic indices of n ∼ 1.2, close to pure exponential discs all the way from z = 2.23 to z = 0.4. At z = 0, we find typical sizes of 4-5 kpc. Our results show that, when using GALFIT, cosmological dimming has a negligible impact on the derived effective radius for galaxies with <10 kpc, but we find an ∼20 per cent bias on the estimate of the median Sersic indices, rendering galaxies more disc-like. Star-forming galaxies have grown on average by a factor of 2-3 in the last 11 Gyr with re ∝ (1 + z)–0.75. By exploring the evolution of the stellar mass-size relation, we find evidence for a stronger size evolution of the most massive star-forming galaxies since z ∼ 2, as they grow faster towards z ∼ 0 when compared to the lower stellar mass counterparts. As we are tracing the rest-frame blue/UV, we are likely witnessing the growth of discs where star formation is ongoing in galaxies while their profiles remain close to exponential discs, n <= 1.5, across the same period.
Abstract Copyright:
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Journal keyword(s):
galaxies: evolution - galaxies: star formation - galaxies: structure - galaxies: structure
Simbad objects:
5
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