期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 458, 期 3, 页码 3181-3209出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/stw502
关键词
Galaxy: evolution; galaxies: clusters: general; galaxies: elliptical and lenticular, cD; galaxies: formation; galaxies: fundamental parameters; galaxies: high-redshift
资金
- Deutsche Zentrum fur Luft- und Raumfahrt (DLR) [50OR1513]
- Deutsche Forschungsgemeinschaft [3871/1-1]
- UK Science and Technology Facilities Council [ST/H002456/1, ST/K00106X/1, ST/H504862/1]
- Christ Church, Oxford
- Science and Technology Facilities Council [STFC] [ST/H002456/1, ST/K00106X/1, ST/J002216/1]
- Hintze Research Fellowship
- Science and Technology Facilities Council [ST/J002216/1, ST/K00106X/1, ST/H002456/1, ST/M007650/1, ST/H504862/1, ST/N002717/1] Funding Source: researchfish
- STFC [ST/J002216/1, ST/H002456/1, ST/K00106X/1, ST/H504862/1, ST/N002717/1, ST/M007650/1] Funding Source: UKRI
We analyse the sizes, colour gradients and resolved stellar mass distributions for 36 massive and passive galaxies in the cluster XMMUJ2235-2557 at z = 1.39 using optical and near-infrared Hubble Space Telescope (HST) imaging. We derive light-weighted Sersic fits in five HST bands (i(775), z(850), Y-105, J(125), H-160), and find that the size decreases by similar to 20 per cent going from i(775) to H-160 band, consistent with recent studies. We then generate spatially resolved stellarmassmaps using an empirical relationship between M-*/L-H160 and (z(850) - H-160) and use these to derive mass-weighted Sersic fits: the mass-weighted sizes are similar to 41 per cent smaller than their rest-frame r-band counterparts compared with an average of similar to 12 per cent at z similar to 0. We attribute this evolution to the evolution in the M-*/L-H160 and colour gradient. Indeed, as expected, the ratio of mass-weighted to light-weighted size is correlated with the M-*/L gradient, but is also mildly correlated with the mass surface density and mass-weighted size. The colour gradients (del(z -H)) are mostly negative, with a median value of similar to 0.45 mag dex(-1), twice the local value. The evolution is caused by an evolution in age gradients along the semimajor axis (a), with del(age) = dlog (age)/dlog (a) similar to-0.33, while the survival of weaker colour gradients in old, local galaxies implies that metallicity gradients are also required, with del(Z) = dlog (Z)/dlog (a) similar to-0.2. This is consistent with recent observational evidence for the inside-out growth of passive galaxies at high redshift, and favours a gradual mass growth mechanism, such as minor mergers.
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