J/A+A/666/A54 Brightest Cluster Galaxies from CFH TLS (Chu+, 2022)
Physical properties of more than one thousand brightest cluster galaxies
detected in the Canada-France-Hawaii Telescope Legacy Survey.
Chu A., Sarron F., Durret F., Marquez I.
<Astron. Astrophys., 666, A54 (2022)>
=2022A&A...666A..54C 2022A&A...666A..54C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Photometry ; Optical ; Redshifts ;
Morphology
Keywords: galaxies: clusters: general - galaxies: evolution -
galaxies: formation
Abstract:
Brightest cluster galaxies (BCGs) are very massive elliptical galaxies
found at the centres of clusters. Their study gives clues to the
formation and evolution of the clusters in which they are embedded.
We analyse here in a homogeneous way the properties of a sample of
more than 1000 BCGs in the redshift range 0.15<z<0.7, based on
images from the Canada-France-Hawaii Telescope Legacy Survey.
Based on a recent catalogue of 1371 clusters, we applied our automatic
BCG detection algorithm and successfully identified 70% of the BCGs in
our sample. We analysed their 2D photometric properties with GALFIT.
We also compared the position angles of the BCG major axes with those
of the overall cluster to which they belong.
We find no evolution of the BCG properties with redshift up to z=0.7,
in agreement with previous results by Chu et al. (2021A&A...649A..42C 2021A&A...649A..42C,
Cat. J/A+A/649/A42), who analysed a sample an order of magnitude
smaller, but reaching a redshift z=1.8. The Kormendy relation for BCGs
is tight and consistent with that of normal elliptical galaxies and
BCGs measured by other authors. The position angles of the BCGs and of
the cluster to which they belong agree within 30 degrees for 55% of
the objects with well-defined position angles. The study of this very
large sample of more than 1000 BCGs shows that they were mainly formed
before z=0.7 as we find no significant growth for the luminosities and
sizes of central galaxies. We discuss the importance of the
intracluster light in the interpretation of these results. We
highlight the role of image depth in the modelling of the luminosity
profiles of BCGs, and give evidence of the presence of an inner
structure which can only be resolved on deep surveys with limiting
apparent magnitude at 80% completeness m80>26mag/arcsec2.
Description:
Brightest cluster galaxies (BCGs) are very massive elliptical galaxies
found at the centres of clusters. Their study gives clues to the
formation and evolution of the clusters in which they are embedded. We
analyse here in a homogeneous way the properties of a sample of more
than 1000 BCGs in the redshift range 0.15<z<0.7, based on images from
the Canada-France-Hawaii Telescope Legacy Survey.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 36 1238 Catalogue of the 1238 BCGs detected in the CFHTLS
table2.dat 101 974 Physical properties of the 974 BCGs with good
model fitting
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See also:
J/A+A/649/A42 : BCG up to z=1.80 physical properties (Chu+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name ID of the BCG (WN-NNNN)
9- 19 F11.7 deg RAdeg Right ascension (J2000)
21- 31 F11.7 deg DEdeg Declination (J2000)
33- 36 F4.2 --- zph Photometric redshift
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name ID of the BCG (WN-NNNN)
9- 15 A7 --- Sersicfit Model used to fit the BCG (1)
17- 23 F7.3 mag MAG Absolute magnitude
25- 30 F6.3 mag/arcsec2 SuBrmeanDim Mean surface brightness corrected for
cosmological dimming
32- 38 F7.3 kpc Reff Effective radius
40- 44 F5.2 --- n Sersic index
46- 49 F4.2 --- b/a Minor over major axis b/a
51- 53 I3 deg theta Position angle
55- 61 F7.3 mag MAGint ?=-99.99 Absolute magnitude of the
inner component
63- 69 F7.3 mag/arcsec2 SuBrmeanInt ?=-99.99 Mean surface brightness
corrected for cosmological dimming of
the inner component
71- 76 F6.2 kpc ReffInt ?=-99.99 Effective radius of the
inner component
78- 83 F6.2 --- nInt ?=-99.99 Sersic index of the
inner component
85- 90 F6.2 --- b/aInt ?=-99.99 Minor over major axis b/a of
the inner component
92- 94 I3 deg thetaInt ?=-99 Position angle of the
inner component
96-101 F6.3 mag g-r Color index g-r
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Note (1): Model used to fit the BCG as follows:
Sersic = 1 component
Sersic2 = 2 components
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Acknowledgements:
Aline Chu, chu(at)iap.fr
(End) Patricia Vannier [CDS] 25-Apr-2023