J/MNRAS/494/5619 Precise benchmark for cluster scaling relations (Shetty+, 2020)
A precise benchmark for cluster scaling relations: Fundamental Plane, Mass
Plane, and IMF in the Coma cluster from dynamical models.
Shetty S., Cappellari M., McDermid R.M., Krajnovic D., de Zeeuw P.T.,
Davies R.L., Kobayashi C.
<Mon. Not. R. Astron. Soc., 494, 5619-5635 (2020)>
=2020MNRAS.494.5619S 2020MNRAS.494.5619S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, radius ; Clusters, galaxy ; Positional data ;
Photometry ; Spectroscopy ; Optical
Keywords: galaxies: clusters: general - galaxies: evolution -
galaxies: fundamental parameters - galaxies: kinematics and dynamics
Abstract:
We study a sample of 148 early-type galaxies in the Coma cluster using
SDSS photometry and spectra, and calibrate our results using detailed
dynamical models for a subset of these galaxies, to create a precise
benchmark for dynamical scaling relations in high-density
environments. For these galaxies, we successfully measured global
galaxy properties, modelled stellar populations, and created dynamical
models, and support the results using detailed dynamical models of 16
galaxies, including the two most massive cluster galaxies, using data
taken with the SAURON IFU. By design, the study provides minimal
scatter in derived scaling relations due to the small uncertainty in
the relative distances of galaxies compared to the cluster distance.
Our results demonstrate low (=<55 per cent for 90th percentile) dark
matter fractions in the inner 1Re of galaxies. Owing to the study
design, we produce the tightest, to our knowledge, IMF-σe
relation of galaxies, with a slope consistent with that seen in local
galaxies. Leveraging our dynamical models, we transform the classical
Fundamental Plane of the galaxies to the Mass Plane. We find that the
coefficients of the Mass Plane are close to predictions from the
virial theorem, and have significantly lower scatter compared to the
Fundamental Plane. We show that Coma galaxies occupy similar locations
in the (M*-Re) and (M*-σe) relations as local field
galaxies but are older. This, and the fact we find only three slow
rotators in the cluster, is consistent with the scenario of
hierarchical galaxy formation and expectations of the kinematic
morphology-density relation.
Description:
The galaxy sample for this study is selected from the sample of 161
galaxies used in Cappellari (2013ApJ...778L...2C 2013ApJ...778L...2C), where the author
selected galaxies within 1deg2 of the Coma cluster centre with total
K-band absolute magnitude limit of MK←21.5, which translates to
M*≳6x109M☉, at a distance of 100Mpc. These criteria were
designed to be identical to the ATLAS3D survey parent sample
(Cappellari et al. 2011MNRAS.413..813C 2011MNRAS.413..813C, Cat. J/MNRAS/413/813).
Of this sample of 161 galaxies, we selected 148 galaxies based on the
availability of spectral data in SDSS 12th data release catalogue
(Alam et al. 2015ApJS..219...12A 2015ApJS..219...12A, Cat. V/147). For a subset of 53
galaxies, we have data taken using the SAURON IFS mounted on the
William Herschel Telescope. Of these 53 galaxies, due to issues of
signal-to-noise (S/N), unexpected artefacts in the data, etc.,
dynamical models for only 42 galaxies could be made. Of these, two
galaxies did not have SDSS spectral observations.
Objects:
--------------------------------------------------------------
RA (ICRS) DE Designation(s)
--------------------------------------------------------------
11 22 59.99 +23 53 59.9 NAME Coma Supercluster = BSCG 10
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 123 42 Results of analysis of the SAURON subset of
Coma cluster galaxies
tableb1.dat 93 136 Results of analysis of the full sample of Coma
cluster galaxies
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See also:
J/MNRAS/413/813 : ATLAS3D project. I. (Cappellari+, 2011)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Galaxy name
11- 20 F10.6 deg RAdeg Right ascension (J2000)
22- 30 F9.6 deg DEdeg Declination (J2000)
32- 37 F6.3 arcsec Re Galaxy effective radius (G1)
39- 44 F6.3 arcsec ReMaj Major axis of the isophote containing
half the light of the galaxy (G2)
46- 51 F6.2 [km/s] sigma Logarithm of the velocity dispersion
(G3)
53- 59 F7.3 mag rMAG Absolute magnitude on the SDSS r-band
61- 66 F6.3 [Msun/Lsun] M/LJAM Logarithm of the dynamical M/L derived
using the self-consistent model (G4)
68- 73 F6.3 [Msun/Lsun] M/LAMdyn Logarithm of the dynamical M/L derived
using the AM model (G4)
75- 78 F4.2 --- fAM Dark matter fraction for the AM model
80- 85 F6.3 [Msun/pc3] logrho Logarithm of the total density
ρtot (1)
87- 92 F6.3 --- gamma Slope of the power-law profile
94- 99 F6.3 Msun/Lsun M/LPLdyn Logarithm of the dynamical M/L derived
using the PL model
101- 104 F4.2 --- fPL Dark matter fraction for the PL model
106- 111 F6.3 [Msun] logMass Logarithm of the stellar mass of the
galaxy
113- 116 F4.2 --- epsilon ? Intrinsic ellipticity
118- 121 F4.2 --- lRe ? λRe parameter (2)
123 I1 --- Qual [0/2] Quality of the data (3)
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Note (1): The best-fitting total density profile of the PL model, ρtot(r),
is defined as the linear sum of the stellar density profile and the
dark matter halo of the galaxy
Note (2): The parameter λRe was measured using the equation from
Emsellem et al. (2007MNRAS.379..401E 2007MNRAS.379..401E) (see Section 5.5)
Note (3): Quality as follows:
0 = Galaxies for whom reliable kinematics could not be derived
1 = Galaxies acceptable dynamical models that reproduce some of the
observed kinematic structures
2 = Galaxies with good dynamical models that reproduce the observed
kinematic structures
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Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Galaxy name
11- 20 F10.6 deg RAdeg Right ascension (J2000)
22- 30 F9.6 deg DEdeg Declination (J2000)
32- 37 F6.3 arcsec Re Galaxy effective radius (G1)
39- 44 F6.3 arcsec ReMaj Major axis of the isophote containing
half the light of the galaxy (G2)
46- 51 F6.2 km/s sigma Logarithm of the velocity dispersion
(G3)
53- 59 F7.3 mag rMAG Absolute magnitude on the SDSS r-band
61- 65 F5.3 [Msun/Lsun] M/LJAM Logarithm of the dynamical M/L
derived using the self-consistent
model (G4)
67- 72 F6.3 [Msun/Lsun] M/LAMdyn Logarithm of the dynamical M/L
derived using the AM model (G4)
74- 78 F5.3 [Msun/Lsun] M/LSalppop Logarithm of M/L derived by the
regularized mass-weighted fitting of
the galaxy spectra with stellar
population models, assuming a
Salpeter IMF
80- 84 F5.2 Gyr Age Mass-weighted stellar age of the
galaxy
86- 91 F6.3 [Msun] logMass Logarithm of the stellar mass of the
galaxy
93 I1 --- SAURON [0/1] Indicates if the galaxy has
SAURON observations (1) or not
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Global Notes:
Note (G1): Effective radius derived from the multi-Gaussian expansion (MGE)
parametrization of the galaxy photometry and have been multiplied by
1.35 as per the offset observed in ATLAS3D (see Section 4.2)
Note (G2): ReMaj derived as per the prescription in Cappellari et al.
(2013MNRAS.432.1709C 2013MNRAS.432.1709C) and has been multiplied by 1.35, as done for
the effective radius
Note (G3): The error in the derived velocity dispersion is 0.042dex or 10 per
cent
Note (G4): The errors on M/LJAM and M/LAMdyn are equal to of 0.04dex or 10 per
cent
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 02-Jun-2023