J/MNRAS/485/1528 Morphological study of galaxies in ZwCl0024+1652 (Amado+, 2019)
A morphological study of galaxies in ZwCl0024+1652, a galaxy cluster at redshift
z∼0.4.
Amado Z.B., Povic M., Sanchez-Portal M., Tessema S.B., Bongiovanni A.,
Cepa J., Cervino M., Gonzalez-Serrano J.I., Nadolny J., Perez Garcia A.M.,
Perez-Martinez R., Pintos-Castro I.
<Mon. Not. R. Astron. Soc., 485, 1528-1545 (2019)>
=2019MNRAS.485.1528A 2019MNRAS.485.1528A (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies ; Morphology ; Abundances ;
Photometry ; Optical
Keywords: ZwCl0024+1652 - galaxy cluster - galaxies - Morphology - Early-Type -
Late-Type - Galsvm - Morphological fraction
Abstract:
The well-known cluster of galaxies ZwCl0024+1652 at z∼0.4 lacks an
in-depth morphological classification of its central region. While
previous studies provide a visual classification of a patched area, we
used the public code called galaxy Support Vector Machine (GALSVM) and
HST/ACS data as well as the WFP2 master catalogue to automatically
classify all cluster members up to 1Mpc. GALVSM analyses galaxy
morphologies through support vector machine (SVM). From the 231
cluster galaxies, we classified 97 as early types (ETs) and 83 as late
types (LTs). The remaining 51 stayed unclassified (or undecided). By
cross-matching our results with the existing visual classification, we
found an agreement of 81 per cent. In addition to previous Zwcl0024
morphological classifications, 121 of our galaxies were classified for
the first time in this work. In addition, we tested the location of
classified galaxies on the standard morphological diagrams,
colour-colour and colour-magnitude diagrams. Out of all cluster
members, ∼20 per cent are emission-line galaxies, taking into account
previous GLACE results. We have verified that the ET fraction is
slightly higher near the cluster core and decreases with the
clustercentric distance, while the opposite trend has been observed
for LT galaxies. We found a higher fraction of ETs (54 per cent) than
LTs (46 per cent) throughout the analysed central region, as expected.
In addition, we analysed the correlation between the five
morphological parameters (Abraham concentration, Bershady-Concelice
concentration, asymmetry, Gini, and M20 moment of light) and the
clustercentric distance, without finding a clear trend. Finally, as a
result of our work, the morphological catalogue of 231 galaxies
containing all the measured parameters and the final classification is
available in the electronic form of this paper.
Description:
We used the public HST reduced scientific image of ZwCl0024+16521 from
the observation made on 2004 November 16 with the ACS Wide Field
Camera (WFC) using the F775W filter. The ACS/WFC has a pixel scale of
0.05arcsec/pixel and field of view of 202x202arcsec2. The cluster is
centred at RA=6.64433deg and Dec.=17.16211deg, and the used image
covers the central part of the cluster of∼1Mpc.
To extract redshift information and to identify cluster members, we
used the public ZwCl0024+1652 master catalogue
(http://www.astro.caltech.edu/~smm/clusters/) described in Treu et al.
(2003ApJ...591...53T 2003ApJ...591...53T, Cat. J/ApJ/591/53) and Moran et al.
(2005ApJ...634..977M 2005ApJ...634..977M, J/ApJ/634/977). The catalogue consists of 73318
sources, with photometric and/or spectroscopically confirmed redshifts
available, and covering the area of 0.5x0.5deg2 up to the
clustercentric distance of about 5Mpc. All observations were carried
out with the Canada-France-Hawaii Telescope (CFHT) and its CFH12K wide
field camera, and/or the HST Wide Field and Planetary Camera (WFP2),
as described in Treu et al. (2003ApJ...591...53T 2003ApJ...591...53T, Cat. J/ApJ/591/53).
Besides redshifts, this catalogue includes the visual morphological
classification of sources brighter than I=22.5 (Moran et al.
2005ApJ...634..977M 2005ApJ...634..977M, Cat. J/ApJ/634/977). We cross-matched this
catalogue with our SExtractor catalogue (3515 sources) using a maximum
radius of 2arcsec. This radius was selected after testing different
ones from 1 to 5arcsec and finding it to be the best compromise
between being the counterparts and having multiple matches. We
obtained a total of 255 counterparts (hereafter cluster sample) with
available redshifts.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 236 231 Morphological catalogue of galaxies in the
ZwCl0024+1652 cluster
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See also:
J/ApJ/591/53 : I photometry of Cl 0024+16 (Treu+, 2003)
J/ApJ/634/977 : Redshifts in Cl 0024+16 members (Moran+, 2005)
J/ApJ/671/1503 : Cl 0024+16 and MS 0451-03 spectrophotometry (Moran+, 2007)
J/A+A/578/A30 : Emission-line galaxies in ZwCl0024.0+1652
(Sanchez-Portal+, 2015)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Galaxy index
5- 9 F5.1 --- HST ? HST identification number of the
galaxy
11- 17 F7.5 deg RAdeg Right ascension (J2000)
19- 26 F8.5 deg DEdeg Declination (J2000)
28- 33 F6.4 --- Ellip Ellipticity of the galaxy measured by
SExtractor
35- 41 F7.4 mag/arcsec2 mumean Surface brightness of the galaxy
measured by SExtractor
43- 49 F7.4 --- asym Asymmetry index measured by GALSVM (1)
51- 56 F6.4 --- cAbr Abraham concentration index measured by
GALSVM (2)
58- 63 F6.4 --- GINI GINI coefficient measured by GALSVM (3)
65- 71 F7.4 --- M20 M20 moment of light index measured by
GALSVM (4)
73- 79 F7.4 --- CCon Bershady-Concelice concentration index
measured by GALSVM (5)
81- 87 F7.4 mag F775Wmag MAG_AUTO (F775W) measured by SExtractor
89- 94 F6.4 mag e_F775Wmag Error on F775Wmag
96-101 F6.4 --- z Redshift (6)
103 I1 --- r_z References for z (7)
105-110 F6.4 Mpc Dist Distance of the galaxy from the centre
of the cluster (clustercentric
distance)
112-117 F6.4 --- Prob Final probability of a galaxy to be
early-type taking the uncertainty
into account
119-120 A2 --- Class Final morphological class based on the
probability value (Prob) (8)
122-125 A4 --- MType Visual morphology as given in
Moran et al. (2007ApJ...671.1503M 2007ApJ...671.1503M,
Cat. J/ApJ/671/1503)
127-131 A5 --- ELGType Emission line galaxy (ELG) type adapted
from Sanchez-Portal et al.
(2015A&A...578A..30S 2015A&A...578A..30S,
Cat. J/A+A/578/A30)
133-139 F7.4 mag Bmag ? B-band SExtractor MAG_AUTO magnitude
141-147 F7.4 mag Vmag ? V-band SExtractor MAG_AUTO magnitude
149-155 F7.4 mag Rmag ? R-band SExtractor MAG_AUTO magnitude
157-163 F7.4 mag Imag ? I-band SExtractor MAG_AUTO magnitude
165-171 F7.4 mag Jmag ? J-band SExtractor MAG_AUTO magnitude
173-179 F7.4 mag Kmag ? K-band SExtractor MAG_AUTO magnitude
181-187 F7.4 mag F814Wmag ? F814W-band SExtractor MAG_AUTO
magnitude
189-194 F6.4 mag e_Bmag ? Error on Bmag
196-201 F6.4 mag e_Vmag ? Error on Vmag
203-208 F6.4 mag e_Rmag ? Error on Rmag
210-215 F6.4 mag e_Imag ? Error on Imag
217-222 F6.4 mag e_Jmag ? Error on Jmag
224-229 F6.4 mag e_Kmag ? Error on Kmag
231-236 F6.4 mag e_F814Wmag ? Error on F814Wmag
--------------------------------------------------------------------------------
Note (1): Asymmetry (ASYM) measures an extent to which a galaxy's light is
rotationally symmetric (Abraham et al. 1994ApJ...432...75A 1994ApJ...432...75A,
1996ApJS..107....1A 1996ApJS..107....1A, Cat. J/ApJS/107/1; Conselice et al.
2003AJ....126.1183C 2003AJ....126.1183C, Cat. J/AJ/126/1183)
Note (2): Abraham concentration index (CABR) is defined as the ratio of fluxes
of the inner isophote at 30 per cent to that of the outer isophote at
90 per cent (Abraham et al. 1994ApJ...432...75A 1994ApJ...432...75A, 1996ApJS..107....1A 1996ApJS..107....1A,
Cat. J/ApJS/107/1)
Note (3): GINI coefficient (GINI) is a statistical term derived from the Lorentz
curve specifying the overall distribution function of the pixel values
of the galaxy (Abraham et al. 2003ApJ...588..218A 2003ApJ...588..218A, Cat. J/ApJ/588/218;
Lotz et al. 2004AJ....128..163L 2004AJ....128..163L, Cat. J/AJ/128/163)
Note (4): M20 moment of light describes the second-order normalized moment of
the 20 per cent brightest pixels of the particular galaxy
(Abraham et al. 2003ApJ...588..218A 2003ApJ...588..218A, Cat. J/ApJ/588/218;
Lotz et al. 2004AJ....128..163L 2004AJ....128..163L, Cat. J/AJ/128/163)
Note (5): Bershady-Conselice concentration index (CCON) measures a light ratio
within a circular inner aperture (radii comprising 20 per cent of the
total flux) to the outer aperture (radii containing 80 per cent of the
total flux) of the galaxy (Bershady et al. 2000AJ....119.2645B 2000AJ....119.2645B;
Conselice et al. 2000ApJ...529..886C 2000ApJ...529..886C, 2003AJ....126.1183C 2003AJ....126.1183C,
Cat. J/AJ/126/1183)
Note (6): Redshift values for each galaxy from the public data of the
ZwCl0024+1652 master catalogue generated by a team working on
'A Wide Field Survey of Two z=0.5 Galaxy Clusters' (see Treu et al.
2003ApJ...591...53T 2003ApJ...591...53T, Cat. J/ApJ/591/53 and Moran et al.
2005ApJ...634..977M 2005ApJ...634..977M, Cat. J/ApJ/634/977)
Note (7): References as follows:
1 = Spectroscopic redshift (see Moran et al. 2007ApJ...671.1503M 2007ApJ...671.1503M,
Cat. J/ApJ/671/1503)
2 = Spectroscopic redshift (see Moran et al. 2007ApJ...671.1503M 2007ApJ...671.1503M,
Cat. J/ApJ/671/1503)
3 = Spectroscopic redshift (see Moran et al. 2007ApJ...671.1503M 2007ApJ...671.1503M,
Cat. J/ApJ/671/1503)
4 = Spectroscopic redshift (see Moran et al. 2007ApJ...671.1503M 2007ApJ...671.1503M,
Cat. J/ApJ/671/1503)
5 = Spectroscopic redshift (see Moran et al. 2007ApJ...671.1503M 2007ApJ...671.1503M,
Cat. J/ApJ/671/1503)
6 = Redshift from DEIMOS
7 = Secure photometric redshift (see Smith et al. 2005ApJ...620...78S 2005ApJ...620...78S)
8 = Fairly unreliable photo-z (fewer bands,fainter)
Note (8): Morphological class as follows:
ET = Early type (probability=Prob)
LT = Late type (probability=1-Prob)
UD = Undecided
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 15-Sep-2022