Galaxy And Mass Assembly (GAMA): Gas fuelling of spiral galaxies in the local Universe II. - Direct measurement of the dependencies on redshift and host halo mass of stellar mass growth in central disc galaxies

M. W. Grootes, A. Dvornik, R. J. Laureijs, R. J. Tuffs, C. C. Popescu, A. S.G. Robotham, J. Liske, M. J.I. Brown, B. W. Holwerda, L. Wang

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2 Citations (Scopus)

Abstract

We present a detailed analysis of the specific star formation rate-stellar mass (sSFR-M*) of z ≤ 0.13 disc central galaxies using a morphologically selected mass-complete sample (M* ≥ 109.5M). Considering samples of grouped and ungrouped galaxies, we find the sSFR-M* relations of disc-dominated central galaxies to have no detectable dependence on host dark-matter halo (DMH) mass, even where weak-lensing measurements indicate a difference in halo mass of a factor ≳ 5.We further detect a gradual evolution of the sSFR-M* relation of non-grouped (field) central disc galaxies with redshift, even over a Δz ≈ 0.04 (≈5 × 108 yr) interval, while the scatter remains constant. This evolution is consistent with extrapolation of the 'main sequence of star-forming-galaxies' from previous literature that uses larger redshift baselines and coarser sampling. Taken together, our results present new constraints on the paradigm under which the SFR of galaxies is determined by a self-regulated balance between gas inflows and outflows, and consumption of gas by star formation in discs, with the inflow being determined by the product of the cosmological accretion rate and a fuelling efficiency - -Mb,haloζ. In particular, maintaining the paradigm requires -Mb,haloζ to be independent of themass Mhalo of the host DMH. Furthermore, it requires the fuelling efficiency ζ to have a strong redshift dependence (∝(1 + z)2.7 forM* = 1010.3M over z = 0-0.13), even though no morphological transformation to spheroids can be invoked to explain this in our disc-dominated sample. The physical mechanisms capable of giving rise to such dependencies of ζ on Mhalo and z for discs are unclear.

Original languageEnglish
Pages (from-to)1015-1034
Number of pages20
JournalMonthly Notices of the Royal Astronomical Society
Volume477
Issue number1
DOIs
Publication statusPublished - 11 Jun 2018

Keywords

  • Galaxies: Evolution
  • Galaxies: Groups: General
  • Galaxies: ISM
  • Galaxies: Spiral
  • Gravitational lensing: Weak
  • Intergalactic medium

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