J/MNRAS/511/139 CRDs galaxies candidates in SDSS-IV MaNGA (Bevacqua+, 2022)
SDSS-IV MaNGA Integral-field kinematics and stellar population of a sample of
galaxies with counter-rotating stellar discs selected from about 4000 galaxies.
Bevacqua D., Cappellari M., Pellegrini S.
<Mon. Not. R. Astron. Soc., 511, 139-157 (2022)>
=2022MNRAS.511..139B 2022MNRAS.511..139B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Galaxies, nearby ; Galaxy catalogs ; Morphology ;
Spectroscopy ; Photometry ; Optical ; Stars, masses ;
Galaxies, radius ; Positional data ; Stars, ages ; Abundances ;
Velocity dispersion
Keywords: galaxies: elliptical and lenticular, cD - galaxies: evolution -
galaxies: fundamental parameters - galaxies: ISM -
galaxies: kinematics and dynamics - galaxies: structure
Abstract:
We present the integral-field kinematics and stellar population
properties of 64 galaxies (61 are Early-Type galaxies; ETGs) with
Counter-Rotating stellar Disks (CRD) selected from about 4000 galaxies
in the MaNGA survey, based on evidence of counter-rotation or two
velocity dispersion peaks in the kinematic maps. For 17 CRDs, the
counter-rotating components can also be separated spectroscopically.
The frequency of CRDs in MaNGA is <5 per cent for ellipticals, <3 per
cent for lenticulars, and <1 per cent for spirals (at 95 per cent
confidence level), consistent with previous estimates. We produced age
and metallicity maps, and compared the stellar population properties
to those of the general ETGs population. We found that CRDs have
similar trends in age and metallicity to ETGs, but are less metallic
at low masses, and show flatter age and steeper metallicity gradients,
on average. A comparison of the velocity fields of the ionized gas and
the stars reveals that in 33 cases the gas corotates with either the
inner (15 cases) or outer (18 cases) stellar disc, and in nine cases
it is misaligned. In most cases the gas corotates with the younger
disc. Evidence of multimodality in the stellar population is found in
31 galaxies, while the 14 youngest and least massive galaxies show
ongoing star formation; 14 galaxies, instead, exhibit unimodality, and
are the oldest and most massive. As a general result, our work
indicates that CRDs form primarily via gas accretion in retrograde
rotation with respect to a pre-existing stellar disc.
Description:
We make use of the statistical power of the MaNGA survey, which has
observed ∼10000 galaxies, to build a large sample of counter-rotators.
The Integral-Field Spectroscopy (IFS) data used in this study are
taken from the Data Release 16 (DR16; Ahumada et al.
2020ApJS..249....3A 2020ApJS..249....3A, Cat. V/154) of the MaNGA survey. DR16 includes
IFS data for 4597 unique galaxies observed in the redshift range
0.01 < z < 0.15. The physical properties of these 4597 galaxies (e.g.
morphological classification, mass, ellipticity etc.) used in this
paper were kindly provided by Mark Graham, the tableg18.dat and refer
to Graham et al. (2019arXiv191005139G 2019arXiv191005139G) for a detailed description of
how the properties have been measured (i.e see also Graham et al.
2018MNRAS.477.4711G 2018MNRAS.477.4711G, Cat. J/MNRAS/477/4711).
As the section 2.2 Selection criteria shows we sample 64 galaxies with
counter-rotating stellar discs by performing a visual inspection of
the kinematic maps, provided by the MaNGA Data Analysis Pipeline and
looking for evidences of counter-rotation in the mean stellar velocity
(V*) maps, and the presence of the two characteristic peaks in the
stellar velocity dispersion (σ*) maps (i.e see also sections 3
and 4 for CRDs detections, kinematics and stellar population
properties of CRDs). The table1.dat presents CRDs physical and
morphological properties of our sample.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 73 64 Properties of Counter-Rotating stellar Disks
galaxy candidates
tableg18.dat 46 4460 Galaxy properties estimated in Graham et al.
2019arXiv191005139G 2019arXiv191005139G
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See also:
J/MNRAS/477/4711 : Stellar angular momentum for MaNGA galaxies (Graham+, 2018)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16)
(Ahumada+, 2020)
J/MNRAS/413/813 : ATLAS3D project. I. (Cappellari+, 2011)
J/AJ/154/86 : MaNGA catalog, DR15 (Wake+, 2017)
J/AJ/167/31 : Nearby galaxies within 50Mpc from NSA, LVG & Leda
(Ohlson+, 2024)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- MaNGAId MaNGA-ID associated with a unique
MaNGA galaxy (MaNGA-ID)
10 I1 --- n_MaNGAId [1/2]? Note on MaNGAId objects (1)
12- 13 A2 --- Mtype Galaxy Hubble morphology (Morphology)
(2)
15- 19 F5.2 [Msun] logM* Stellar mass taken from Graham et al.
2019arXiv191005139G 2019arXiv191005139G (log10M*)
21- 25 F5.2 kpc Pth50 Elliptical Petrosian 50 per cent light
radius in SDSS r-band (Re)
27- 31 F5.1 deg DPA ? Difference of the kinematic position
angles between the stellar and the gas
velocity fields (ΔPA) (3)
33- 37 A5 --- n_DPA Note on DPA (star/gas_alignment) (4)
39- 43 A5 --- Pop [young old nan] Correspond to the
corotation of the gaseous disk with
the younger or older disk
(star/gas_vs.pop)
45- 49 F5.2 [yr] logAge Luminosity weighted mean age within 1
Re as in the equation 8 of the
section 4.1 Stellar population maps
(log10<Age>)
51- 55 F5.2 [Sun] [M/H] Luminosity weighted mean metallicity
within 1 Re as in the equation 9 of
the section 4.1 Stellar population
maps (<[M/H]>)
57- 61 F5.2 [yr/kpc] GradAge Gradient of Age (GradAge) (5)
63- 67 F5.2 [Sun/kpc] Grad[M/H] Gradient of metallicity (Grad[M/H]) (5)
69- 73 A5 --- Modality Modality of the weights maps from
regularized fits (Modality) (6)
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Note (1): If it indicates 1 galaxies labelled as 'CRD in formation' like
explained in 2 section 2.2 Selection criteria and 2 marks galaxies
exhibiting two minima in the Χ2 map for two counter-rotating
discs are spectroscopically distinguishable as explained in
section 3.3 Two-component fits and Χ2 maps.
Note (2): Hubble classification determined visually as follows:
E = Elliptical, 38 sources in our sample
S = Spiral, 1 source in our sample
S0 = Lenticular, 23 sources in our sample
U = Unclassified, 2 sources in our sample
Note (3): As described in the section 3.4 Gas and stars position angles and
kinematic misalignment, associated error 7°.
Note (4): Note on DPA as follows:
inner = Corotation of the gaseous disk with the inner stellar disk,
15 sources in our sample
outer = Corotation of the gaseous disk with the outer stellar disk,
18 sources in our sample
mis = Misalignment between gaseous and stellar disk,
9 sources in our sample
nan = None available trend, 22 sources in our sample
Note (5): As explained in the section 4.1 Stellar population maps, to evaluate
gradients, we first construct the radial profiles of these properties
by taking the median values inside elliptical annuli of
logarithmically-spaced radii, varying from Re/8 to Re.
Then, we take as gradients the slopes of linear fits performed on
the logarithmic profiles, using the LTS_LINEFIT routine described
in Cappellari et al. (2013MNRAS.432.1709C 2013MNRAS.432.1709C) as
gradAge = Δ<logAge>/ΔlogR and
grad[M/H] = Δ<[M/H]>/ΔlogR.
Note (6): Modality of the weights maps have 4 labels as follows:
multi = multimodality, 31 sources in our sample
uni = unimodality, 14 sources in our sample
sf = star-forming, 14 sources in our sample
nan = None modality, 5 sources in our sample
As presented in the section 4.3 Regularized fits and multiple
populations, to investigate the presence of multiple stellar
populations in the same spatial region, we performed regularized fits
in every spatial bin. The weights fraction maps represent the weights,
entering the same equations 8 and 9 of the section 4.1 Stellar
population maps, of the regularized fits of the SSPs. Based on our
visual assessment of the number of well-isolated peaks in these maps,
we distinguish the presence of 'unimodality' and 'multimodality' in
the stellar population, if there are one or multiple peaks. More, we
further distinguish multimodal galaxies between those who exhibit the
same multimodality in all the considered spatial bins, and those who
instead vary significantly at different bins, and label the latter
as 'star-forming'.
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Byte-by-byte Description of file: tableg18.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- MaNGAId MaNGA-ID associated with a unique MaNGA
galaxy (MaNGA-ID)
11 A1 --- Clean [Y N] In clean sample? (CleanSample?) (1)
13- 16 A4 --- Mtype Hubble classification type as in Section 3.6
of Graham et al. 2018MNRAS.477.4711G 2018MNRAS.477.4711G, Cat.
J/MNRAS/477/4711 (HubbleGroup) (2)
18 A1 --- Rotator [F S] Whether the galaxy is a fast 3900
sources or slow rotator 560 sources
(F/SRotator)
20- 23 A4 --- Classkin Kinematic classification as described in
Section 3.4 of Graham et al.
2018MNRAS.477.4711G 2018MNRAS.477.4711G, Cat. J/MNRAS/477/4711
(KClass) (3)
25- 29 F5.3 --- LambdaRe ? The spin parameter measured within the
effective radius from Graham et al.
2018MNRAS.477.4711G 2018MNRAS.477.4711G, Cat. J/MNRAS/477/4711
,also defined in the equation 1 of our work
(lambda_Re)
31- 35 F5.3 --- Ell Ellipticity 1-b/a where a/b=semi-major/minor
axes taken from either the MGE fit, the
photometric fit from find galaxy or the NSA
catalogue (ellipticity)
37- 41 F5.2 [Msun] logM* Stellar mass either calculated from the
absolute KS using equation 2 of Cappellari
2013ApJ...778L...2C 2013ApJ...778L...2C or taken from the NSA
catalogue and scaled to 2MASS (log10M*)
43- 46 F4.2 km/s sigma ? Effective velocity dispersion calculated
using equation 29 of Cappellari et al.
2013MNRAS.432.1709C 2013MNRAS.432.1709C (log10sigma_e)
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Note (1): Yes for 3899 sources and no for 561 sources, as criteria given in
Section 3.6 of Graham et al. 2018MNRAS.477.4711G 2018MNRAS.477.4711G,
Cat. J/MNRAS/477/4711.
Note (2): Hubble classification determined visually as follows:
E = Elliptical, 1351 sources in our sample
I = Irregular, 195 sources in our sample
M/CP = Merger or close pair, 204 sources in our sample
S = Spiral, 798 sources in our sample
S0 = Lenticular, 1817 sources in our sample
U = Unclassified, 95 sources in our sample
Note (3): Kinematic classification as follows:
R = Regular rotator, 3773 sources in our sample
NR = No Rotation, 261 sources in our sample
M/CP = Merger or close pair, 202 sources in our sample
KDC = Kinematically decoupled core, 24 sources in our sample
F = Flagged, 73 sources in our sample
CR = Complex rotator, 81 sources in our sample
2S = 2σ galaxy, 31 sources in our sample
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History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 14-Jan-2025