TY - JOUR
T1 - SDSS-IV MaNGA
T2 - Environmental Dependence of the Mgb/〈Fe〉-σ Relation for Nearby Galaxies
AU - Zheng, Zheng
AU - Li, Cheng
AU - Mao, Shude
AU - Wang, Huiyuan
AU - Liu, Chao
AU - Mo, Houjun
AU - Yuan, Zhen
AU - Maraston, Claudia
AU - Thomas, Daniel
AU - Yan, Renbin
AU - Bundy, Kevin
AU - Long, R. J.
AU - Parikh, Taniya
AU - Oyarzún, Grecco
AU - Bizyaev, Dmitry
AU - Lacerna, Ivan
N1 - Publisher Copyright:
© 2019. The American Astronomical Society. All rights reserved..
PY - 2019
Y1 - 2019
N2 - We use a sample of ∼3000 galaxies from the MaNGA MPL-7 internal data release to study the α abundance distribution within low-redshift galaxies. We use the Lick index ratio Mgb/ as an α abundance indicator to study relationships between the α abundance distribution and galaxy properties such as effective stellar velocity dispersion within 0.3 effective radii (σ ∗ ), galaxy environment, and dark matter halo formation time (z f ). We find that (1) all galaxies show a tight correlation between Mgb/ and (2) "old" (Hβ < 3) low-σ ∗ galaxies in high local density environment and inner regions within galaxy groups are enhanced in Mgb/, while "young" (Hβ > 3) galaxies and high-mass galaxies show no or less environmental dependence; (3) "old" galaxies with high-z f show enhanced Mgb/ over low- and medium-z f ; and (4) Mgb/ gradients are close to zero and show dependence on σ ∗ but no obvious dependence on the environment or z f . Our study indicates that stellar velocity dispersion or galaxy mass is the main parameter driving the Mgb/ enhancement, although environments appear to have modest effects, particularly for low- and medium-mass galaxies.
AB - We use a sample of ∼3000 galaxies from the MaNGA MPL-7 internal data release to study the α abundance distribution within low-redshift galaxies. We use the Lick index ratio Mgb/ as an α abundance indicator to study relationships between the α abundance distribution and galaxy properties such as effective stellar velocity dispersion within 0.3 effective radii (σ ∗ ), galaxy environment, and dark matter halo formation time (z f ). We find that (1) all galaxies show a tight correlation between Mgb/ and (2) "old" (Hβ < 3) low-σ ∗ galaxies in high local density environment and inner regions within galaxy groups are enhanced in Mgb/, while "young" (Hβ > 3) galaxies and high-mass galaxies show no or less environmental dependence; (3) "old" galaxies with high-z f show enhanced Mgb/ over low- and medium-z f ; and (4) Mgb/ gradients are close to zero and show dependence on σ ∗ but no obvious dependence on the environment or z f . Our study indicates that stellar velocity dispersion or galaxy mass is the main parameter driving the Mgb/ enhancement, although environments appear to have modest effects, particularly for low- and medium-mass galaxies.
KW - galaxies: abundances
KW - galaxies: evolution
KW - galaxies: general
KW - galaxies: statistics
KW - galaxies: stellar content
KW - galaxies: structure
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U2 - 10.3847/1538-4357/ab03d2
DO - 10.3847/1538-4357/ab03d2
M3 - Article
AN - SCOPUS:85063571257
SN - 0004-637X
VL - 873
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 63
ER -