J/MNRAS/495/4820 Velocity gradient and galaxy properties correlation (Lu+, 2020)
SDSS-IV MaNGA: stellar population correlates with stellar root-mean-square
velocity Vrms gradients or total-density-profile slopes at fixed effective
velocity dispersion σe.
Lu S., Cappellari M., Mao S., Ge J., Li R.
<Mon. Not. R. Astron. Soc., 495, 4820-4827 (2020)>
=2020MNRAS.495.4820L 2020MNRAS.495.4820L (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Galaxies, radius ; Velocity dispersion ; Abundances ;
Spectroscopy ; Ultraviolet ; Optical
Keywords: galaxy: evolution - galaxy: kinematics and dynamics -
galaxies: formation - galaxies: structure
Abstract:
Galaxy properties are known to correlate most tightly with the galaxy
effective stellar velocity dispersion σe. Here, we look for
additional trends at fixed σe using 1339 galaxies
(M*≳6x109M☉) with different morphologies in the MaNGA
(DR14) sample with integral-field spectroscopy data. We focus on the
gradients (γrms=σ(Re/4)/σe) of the stellar
root-mean-square velocity (Vrms=sqrt(V2+σ2)), which we
show traces the total mass density gradient γtot derived from
dynamical models and, more weakly, the bulge fraction. We confirm that
γrms increases with σe, age, and metallicity. We
additionally find that these correlations still exist at fixed
σe, where galaxies with larger γrms are found to be
older and more metal-rich. It means that mass density gradients
contain information of the stellar population which is not fully
accounted for by σe. This result puts an extra constraint on
our understanding of galaxy quenching. We compare our results with
galaxies in the IllustrisTNG hydrodynamical simulations and find that,
at fixed σe, similar trends exist with age, the bulge
fraction, and the total mass density slope but, unlike observations,
no correlation with metallicity can be detected in the simulations.
Description:
The galaxies in this study are from the MaNGA sample released by SDSS
DR14 (Abolfathi et al. 2018ApJS..235...42A 2018ApJS..235...42A), which includes 2778
galaxies with different morphologies.
We exclude the galaxies that are merging or have low data quality
(with fewer than 100 Voronoi bins with S/N greater than 10) from our
sample. Besides, we exclude galaxies with low stellar mass
(M*<6x109M☉). The stellar mass of MaNGA galaxies is derived
from Salim et al. (2013MNRAS.432.1862C 2013MNRAS.432.1862C). After excluding the galaxies
described above, we have 1520 galaxies with different morphologies. We
derive the stellar population properties (i.e. age and metallicity)
from Li et al. (2018MNRAS.476.1765L 2018MNRAS.476.1765L, Cat. J/MNRAS/476/1765). We use
the mass-weighted total density slope (γtot) from Li et al.
(2019MNRAS.490.2124L 2019MNRAS.490.2124L) to describe the total mass profiles of galaxies.
The bulge-to-total luminosity ratio (B/T) is from Simard et al.
(2011ApJS..196...11S 2011ApJS..196...11S, Cat. J/ApJS/196/11). After cross-matching these
four catalogues, we have 1339 galaxies with available galaxy
properties in our final sample. The size parameters (Re and
Remaj) used in this work are calculated from the Multi-Gaussian
Expansion (MGE) models (Emsellem, Monnet & Bacon 1994A&A...285..723E 1994A&A...285..723E)
with the fitting algorithm and python software by Cappellari
(2002MNRAS.333..400C 2002MNRAS.333..400C) and are scaled by a factor of 1.35.
For comparison, we also select a sample of simulated galaxies with the
same stellar mass range (M*>6x109M☉) at z=0 from the
state-of-the-art magneto-hydrodynamic cosmological galaxy formation
simulations, the IllustrisTNG simulations (http://www.tng-project.org)
(TNG hereafter; Marinacci et al. 2018MNRAS.480.5113M 2018MNRAS.480.5113M; Naiman et al.
2018MNRAS.477.1206N 2018MNRAS.477.1206N; Nelson et al. 2018MNRAS.475..624N 2018MNRAS.475..624N; Pillepich et
al. 2018MNRAS.475..648P 2018MNRAS.475..648P; Springel et al. 2018MNRAS.475..676S 2018MNRAS.475..676S). In this
work, we use its full-physics version with a cubic box of 110.7kpc
side length (TNG100) which has been made publicly available (Nelson et
al. 2019ComAC...6....2N 2019ComAC...6....2N).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tables1.dat 39 1339 Related parameters of 1339 MaNGA galaxies
tables2.dat 56 5105 Related parameters of 5015 IllustrisTNG galaxies
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See also:
J/AJ/154/86 : MaNGA catalog, DR15 (Wake+, 2017)
Byte-by-byte Description of file: tables1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- ID MaNGA identifier (NN-NNNNNNNNN)
11- 14 F4.2 [arcsec] logRe Logarithm of the half-light radius Re
16- 19 F4.2 [arcsec] logRemaj Logarithm of the major axis of the
half-light isophote Remaj
21- 24 F4.2 [km/s] logsigRe/4 Luminosity-weighted velocity dispersion
within a circular aperture with radius
Re/4 (σ(Re/4))
26- 29 F4.2 [km/s] logsigRe Luminosity-weighted velocity dispersion
within an elliptical aperture of area
A=πRe2 (σe)
31- 34 F4.2 --- gammarms Gradient of the stellar root-mean-square
velocity
γrms=σ(Re/4)/σe
36- 39 F4.2 --- gammatot Mass-weighted total density slope from
Li et al. (2019MNRAS.490.2124L 2019MNRAS.490.2124L)
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Byte-by-byte Description of file: tables2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- ID IllustrisTNG galaxy identifier
8- 12 F5.2 [kpc] logRe Logarithm of the half-light radius Re
14- 18 F5.2 [kpc] logRemaj Logarithm of the major axis of the
half-light isophote Remaj
20- 23 F4.2 [km/s] logsigRe/4 Luminosity-weighted velocity dispersion
within a circular aperture with radius
Re/4 (σ (Re/4))
25- 28 F4.2 [km/s] logsigRe Luminosity-weighted velocity dispersion
within an elliptical aperture of area
A=πRe2 (σe)
30- 33 F4.2 --- gammarms Gradient of the stellar root-mean-square
velocity
γrms=σ(Re/4)/σe
35- 39 F5.2 [yr] logage Logarithm of the age
41- 45 F5.2 [-] [Z/H] Metallicity
47- 50 F4.2 --- B/T Bulge-to-total ratio from Xu et al.
(2019MNRAS.489..842X 2019MNRAS.489..842X)
52- 56 F5.2 --- gammatot Mass-weighted total density slope from Li
et al. (2019MNRAS.490.2124L 2019MNRAS.490.2124L)
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 26-Jun-2023