Evolution of galaxy size--stellar mass relation from the Kilo Degree Survey

N. Roy, N. R. Napolitano, F. La Barbera, C. Tortora, F. Getman, M. Radovich, M. Capaccioli, M. Brescia, S. Cavuoti, G. Longo, M. A. Raj, E. Puddu, G. Covone, V. Amaro, C. Vellucci, A. Grado, K. Kuijken, G. Verdoes Kleijn, E. Valentijn

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Abstract

We have obtained structural parameters of about 340,000 galaxies from the Kilo Degree Survey (KiDS) in 153 square degrees of data release 1, 2 and 3. We have performed a seeing convolved 2D single S\'ersic fit to the galaxy images in the 4 photometric bands (u, g, r, i) observed by KiDS, by selecting high signal-to-noise ratio (S/N > 50) systems in every bands. We have classified galaxies as spheroids and disc-dominated by combining their spectral energy distribution properties and their S\'ersic index. Using photometric redshifts derived from a machine learning technique, we have determined the evolution of the effective radius, \Re\ and stellar mass, \mst, versus redshift, for both mass complete samples of spheroids and disc-dominated galaxies up to z ~ 0.6. Our results show a significant evolution of the structural quantities at intermediate redshift for the massive spheroids ($\mbox{Log}\ M_*/M_\odot>11$, Chabrier IMF), while almost no evolution has found for less massive ones ($\mbox{Log}\ M_*/M_\odot <11$). On the other hand, disc dominated systems show a milder evolution in the less massive systems ($\mbox{Log}\ M_*/M_\odot <11$) and possibly no evolution of the more massive systems. These trends are generally consistent with predictions from hydrodynamical simulations and independent datasets out to redshift z ~ 0.6, although in some cases the scatter of the data is large to drive final conclusions. These results, based on 1/10 of the expected KiDS area, reinforce precedent finding based on smaller statistical samples and show the route toward more accurate results, expected with the the next survey releases.
Original languageEnglish
Pages (from-to)1057-1080
JournalMonthly Notices of the Royal Astronomical Society
Volume480
Issue number1
DOIs
Publication statusPublished - 11-Oct-2018

Keywords

  • Astrophysics - Astrophysics of Galaxies
  • DIGITAL SKY SURVEY
  • COLOR-MAGNITUDE RELATION
  • HIGH-REDSHIFT GALAXIES
  • CENTRAL DARK-MATTER
  • INSIDE-OUT GROWTH
  • ULTRA-DEEP-FIELD
  • TO-LIGHT RATIOS
  • BLACK-HOLE MASS
  • ELLIPTIC GALAXIES
  • ASSEMBLY GAMA

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