SDSS-IV MaNGA: stellar population gradients as a function of galaxy environment

Goddard, D.; Thomas, D.; Maraston, C.; Westfall, K.; Etherington, J.; Riffel, R.; Mallmann, N.D.; Zheng, Z.; Argudo-Fern�ndez, M.; Bershady, M.; Bundy, K.; Drory, N.; Law, D.; Yan, R.; Wake, D.; Weijmans, A.; Bizyaev, D.; Brownstein, J.; Lane, R.R.; Maiolino, R.; Masters, K.; Merrifield, M.; Nitschelm, C.; Pan, K.; Roman-Lopes, A.; Storchi-Bergmann, T.

Abstract

We study the internal radial gradients of stellar population properties within 1.5 Re and analyse the impact of galaxy environment. We use a representative sample of 721 galaxies with masses ranging between 109 M⊙ and 1011.5 M⊙ from the SDSS-IV survey MaNGA. We split this sample by morphology into early-type and late-type galaxies. Using the full spectral fitting code firefly, we derive the light and mass-weighted stellar population properties, age and metallicity, and calculate the gradients of these properties. We use three independent methods to quantify galaxy environment, namely the Nth nearest neighbour, the tidal strength parameter Q and distinguish between central and satellite galaxies. In our analysis, we find that early-type galaxies generally exhibit shallow light-weighted age gradients in agreement with the literature and mass-weighted median age gradients tend to be slightly positive. Late-type galaxies, instead, have negative light-weighted age gradients. We detect negative metallicity gradients in both early- and late-type galaxies that correlate with galaxy mass, with the gradients being steeper and the correlation with mass being stronger in late-types. We find, however, that stellar population gradients, for both morphological classifications, have no significant correlation with galaxy environment for all three characterizations of environment. Our results suggest that galaxy mass is the main driver of stellar population gradients in both early and late-type galaxies, and any environmental dependence, if present at all, must be very subtle.

Citation

Goddard, D., Thomas, D., Maraston, C., Westfall, K., Etherington, J., Riffel, R., …Storchi-Bergmann, T. (2017). SDSS-IV MaNGA: stellar population gradients as a function of galaxy environment. Monthly Notices of the Royal Astronomical Society, 465(1), 688-700. https://doi.org/10.1093/mnras/stw2719

• Journal Article Type: Article
• Acceptance Date: Oct 19, 2016
• Online Publication Date: Oct 23, 2016
• Publication Date: Feb 11, 2017
• Deposit Date: Mar 28, 2017
• Publicly Available Date: Mar 28, 2017
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 465
• Issue: 1
• Pages: 688-700
• DOI: https://doi.org/10.1093/mnras/stw2719
• Keywords: surveys, galaxies: elliptical and lenticular, cD, galaxies: evolution, galaxies: formation, galaxies: spiral, galaxies: stellar content
• Public URL: https://nottingham-repository.worktribe.com/output/846295
• Publisher URL: https://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stw2719
• Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved