J/MNRAS/497/466 Groups in the Coma Supercluster (Seth+, 2020)
Evolution of galaxies in groups in the Coma Supercluster.
Seth R., Raychaudhury S.
<Mon. Not. R. Astron. Soc., 497, 466-481 (2020)>
=2020MNRAS.497..466S 2020MNRAS.497..466S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, group ; Clusters, galaxy ; Positional data ;
Radial velocities ; Optical
Keywords: galaxies:clusters:general - galaxies:evolution -
galaxies:groups:general - galaxies:star formation -
galaxies:statistics -
galaxies: clusters: individual: Coma Cluster; Abell 1367
Abstract:
We take a close look at the galaxies in the Coma Supercluster and
assess the role of the environment (in the form of cluster, group, and
supercluster filament) in their evolution, in particular, examining
the role of groups. We characterize the groups according to intrinsic
properties such as richness and halo mass, as well as their position
in the supercluster and proximity to the two rich clusters, Abell 1656
(Coma) and Abell 1367. We devise a new way of characterizing the local
environment using a kernel density estimator. We find that apart from
the dominant effects of the galaxy mass, the effect of the environment
on galaxies is a complex combination of the overdensities on various
scales, which is characterized in terms of membership of groups, and
also of the position of the galaxy on filaments and their proximity to
the infall regions of clusters. Whether the gas can be turned into
stars depends upon the level of pre-processing, which plays a role in
how star formation is enhanced in a given environment. Our results are
consistent with gas accreted in the cold mode from the filaments,
being made available to enhance star formation. Finally, we show that
the Abell 1367 end of the supercluster is in the process of assembly
at present, leading to heightened star formation activity, in contrast
with the Coma-end of the filament system.
Description:
The Yang et al. (2007ApJ...671..153Y 2007ApJ...671..153Y) group catalogue is an optically
selected, volume-limited group catalogue, which is based on the SDSS
DR7 galaxy catalogue (which contains all the galaxies that are used in
the region). The catalogue is based on an iterative halo-based
group-finding algorithm, using an adaptive filter model that considers
the properties of the dark-matter haloes and their distribution in
phase space. Yang et al. (2007ApJ...671..153Y 2007ApJ...671..153Y) assigns a group
membership to every galaxy. Each galaxy in SDSS thus belongs to a
dark-matter halo. Our group sample is limited to those with four or
more member galaxies. Table 2 shows the sample of Yang et al. groups
present in our chosen Coma Supercluster region. The 'Group Galaxies'
sample has 2242 galaxies in 109 groups, which includes the two
clusters (Coma and Abell 1367).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 47 107 Galaxy groups within the Coma Supercluster
(excluding Coma and Abell 1367) from the
Yang et al. (2007ApJ...671..153Y 2007ApJ...671..153Y) catalogue
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID [14/9731] Group identifier
6- 7 I2 h RAh Right ascension (J2000)
9- 10 I2 min RAm Right ascension (J2000)
12- 13 I2 s RAs Right ascension (J2000)
15 A1 --- DE- Declination sign (J2000)
16- 17 I2 deg DEd Declination (J2000)
19- 20 I2 arcmin DEm Declination (J2000)
22- 23 I2 arcsec DEs Declination (J2000)
25- 28 I4 km/s RV Radial velocity
30- 32 I3 --- N Number of galaxies in group
34- 37 F4.1 Lsun L19.5 ? Characteristic luminosity of the group (1)
39- 42 F4.1 Msun M* ? Stellar mass
44- 47 F4.1 Msun Mhalo ? Halo mass
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Note (1): The characteristic luminosity of each group is defined by Yang et al.
(2007ApJ...671..153Y 2007ApJ...671..153Y) as: L19.5=1/f(L19.5,Llim)xΣLi/Ci
where Li is the luminosity of the ith member galaxy, Ci is the
completeness of the survey at the position of that galaxy, and the
summation is over all group members with 0.1Mr-5logh=←19.5.
Finally, f(L19.5,Llim) is a correction factor (0<f<1) that
accounts for the galaxies missed because of the apparent magnitude
limit of the spectroscopic survey.
See Yang et al. (2007ApJ...671..153Y 2007ApJ...671..153Y) for more details.
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 24-Jul-2023