J/MNRAS/522/2223 VSCL clusters and galaxies properties (Hatamkhani+, 2023)
Galaxy clusters in the Vela Supercluster. I. Deep NIR catalogues.
Hatamkhani N., Kraan-korteweg R.C., Blyth S.L., Said K., Elagali A.
<Mon. Not. R. Astron. Soc. 522, 2223-2240 (2023)>
=2023MNRAS.522.2223H 2023MNRAS.522.2223H (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies ; Positional data ; Photometry ;
Infrared ; Velocity dispersion ; Redshifts ; Extinction
Keywords: catalogues - galaxies: clusters: general - galaxies: photometry -
(cosmology:) large-scale structure of Universe - infrared: galaxies
Abstract:
We present six deep Near-InfraRed (JHKs) photometric catalogues of
galaxies identified in six cluster candidates (VC02, VC04, VC05, VC08,
VC10, and VC11) within the Vela Supercluster (VSCL) as part of our
efforts to learn more about this large supercluster, which extends
across the zone of avoidance (l = 272.°5 ± 20°, b = ±10°,
at cz ∼ 18000 km/s). The observations were conducted with the InfraRed
Survey Facility (IRSF), a 1.4-m telescope situated at the South
African Astronomical Observatory (SAAO) in Sutherland. The images in
each cluster cover ∼80 per cent of their respective Abell radii. We
identified a total number of 1715 galaxies distributed over the six
cluster candidates, of which only ∼15 per cent were previously known.
We study the structures and richnesses of the six clusters out to the
cluster-centric completeness radius of rc < 1.5 Mpc and magnitude
completeness limit of Kos < 15.5m, using their iso-density
contour maps and radial density profiles. The analysis shows VC04 to
be the richest of the six. It is a massive cluster comparable to the
Coma and Norma clusters, although its velocity dispersion,
σv = 455 km/s, seems rather low for a rich cluster. VC02 and
VC05 are found to be relatively rich clusters while VC08 is rather
poor. Also, VC05 has the highest central number density among the six.
VC11 is an intermediate cluster that contains two major subclusters
while VC10 has a filament-like structure and is likely not to be a
cluster after all.
Description:
Superclusters are defined as collections of galaxy clusters and groups
above a specified spatial overdensity and contribute to the largest
density enhancements in the cosmic web. In 2017, uncovered an unknown,
relatively nearby extended supercluster centred in the region of the
Vela constellation named VSCL. We investigated the clusters within
VSCL in more detail as a first step towards characterizing this
partially obscured supercluster. The 20 potential galaxy clusters with
velocity dispersions σv > 400 km/s were identified in the
VSCL (i.e see Kraan-Korteweg et al. 2017MNRAS.466L..29K 2017MNRAS.466L..29K, KK2017). NIR
observations are very efficient at probing structures that are
affected by dust, be it dust-enshrouded objects, Galactic objects in
the Milky Way, or galaxies located behind. The NIR is particularly
suitable for the detection of early-type galaxies which are dominated
by an old stellar component and predominantly populate the cores of
galaxy clusters. We pursued NIR imaging observations in the J, H, and
Ks-bands of 10 of the more promising VSCL galaxy clusters. We used the
IRSF telescope located at the SAAO site in Sutherland with the SIRIUS
camera. The instrument has excellent resolution 0.45"/pixel and was
shown to reach a galaxy magnitude deeper than 2MASX in the Ks-band
with 10 min of observing time. It is an ideal instrument for an
in-depth study of the VSCL clusters and, by extension, the VSCL
itself.
This work is the first of a series of papers presenting the analysis
of deep NIR imaging of six VSCL clusters covering 80% of their
respective Abell radii. It provides a detailed description of the NIR
photometry and a first look at the properties of the unveiled
galaxies. Subsequent papers will include a derivation of their
luminosity functions, and a more in-depth dynamical analysis of the
richest VSCL cluster including new spectroscopy of the fainter
galaxies identified in this work.
As explained in section 3, after the preliminary data reduction using
the SIRIUS pipeline, the images were ready for extraction of sources
to create a catalogue of galaxies with their photometric parameters.
We then proceed to galaxy identification and verification in cluster from
visual inspections and photometric source extractions algorithms.
Also, we performed several quality checks to ensure the accuracy of
the derived astrometric and photometric parameters. We computed
galactic extinctions in each bands as described in section 4 with
reddenings maps. The results are exposed in section 5 for the six
clusters with each IRSF pipeline output sample catalogue with each
galaxies astrometics as galactic positions, ellepticities, position
angle inclinations and photometric data as isophotal and total J,H,Ks
magnitudes, galaxy radius, surface brightness and galactic reddening
E(B-V). These quantities are respectively stored peer clusters in
tables vc02.dat, vc04.dat, vc05.dat, vc08.dat, vc10.dat, vc11.dat.
Finally as detailed in section 6, we study the structures and
richnesses of the six cluster candidates with the help of iso-density
contour maps and radial density profiles. It brings galaxies number
density, clusters averaged magnitudes, extinctions and radius. Center
coordinates and cluster properties are summarized in table13.dat.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table13.dat 129 7 Astrometrics, physical properties, structure and
richness parameters of the studied six clusters
vc02.dat 176 315 Identified galaxies with r > 2" in VC02 with
their NIR parameters most relevant for analysis
vc04.dat 176 465 Identified galaxies with r > 2" in VC04 with
their NIR parameters most relevant for analysis
vc05.dat 176 309 Identified galaxies with r > 2" in VC05 with
their NIR parameters most relevant for analysis
vc08.dat 176 243 Identified galaxies with r > 2" in VC08 with
their NIR parameters most relevant for analysis
vc10.dat 176 255 Identified galaxies with r > 2" in VC10 with
their NIR parameters most relevant for analysis
vc11.dat 176 309 Identified galaxies with r > 2" in VC11 with
their NIR parameters most relevant for analysis
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See also:
J/MNRAS/443/41 : Deep NIR photometry of HI galaxies in ZoA (Williams+, 2014)
J/MNRAS/396/2367 : NIR Ks photometry of Norma cluster (A3627) (Skelton+, 2009)
J/MNRAS/383/445 : Radial velocities in the Norma cluster (A3627) (Woudt+,2008)
J/MNRAS/368/534 : Near-infrared study of CIZA J1324.7-5736 (Nagayama+, 2006)
J/MNRAS/354/980 : Near-infrared survey around PKS 1343-601 (Nagayama+, 2004)
J/MNRAS/305/259 : EFAR galaxies redshifts & velocity dispersions
(Wegner+, 1999)
J/MNRAS/301/881 : The ROSAT brightest cluster sample - I. (Ebeling+, 1998)
J/A+A/644/A107 : 3C 129 candidate cluster galaxies (Ramatsoku+, 2020)
J/A+A/635/A135 : Galaxies around M87 (Kashibadze+, 2020)
J/A+A/505/29 : HI observations of 2MASS galaxies in ZoA (van Driel+, 2009)
J/A+A/497/41 : Average Early-type galaxies NIR spectrum (Cesetti+, 2009)
J/A+A/466/481 : Near-infrared survey around PKS 1343-601 (Schroeder+, 2007)
J/ApJ/580/774 : X-ray cluster of galaxies behind the Milky way
(Ebeling+, 2002)
J/AJ/152/50 : Cosmicflows-3 catalog (CF3) (Tully+, 2016)
J/AJ/146/86 : Cosmicflows-2 catalog (CF2) (Tully+, 2013)
J/A+AS/141/123 : Galaxies behind Southern Milky Way (Kraan-Korteweg 2000)
VII/233 : 2MASS All-Sky Extended Source Catalog (XSC)
(IPAC-UMass, 2003-2006)
II/314 : UKIDSS-DR8 LAS, GCS and DXS Surveys (Lawrence+ 2012)
Byte-by-byte Description of file: table13.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Cluster Cluster name (Cluster)
5 A1 --- Sub Subclusters a and b of VC11
7- 8 I2 h RAh Right ascension (J2000)
10- 11 I2 min RAm Right ascension (J2000)
13- 17 F5.2 s RAs Right ascension (J2000)
19 A1 --- DE- Declination sign (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 27 I2 arcsec DEs Declination (J2000)
29- 35 F7.3 deg GLON Galactic longitude (l)
37- 42 F6.3 deg GLAT Galactic latitude (b)
44- 46 I3 --- N Total number of identified galaxies (N)
48- 50 I3 --- Nc Number of identified galaxies brighter
than the completeness magnitude limit
K0s,lim < 15.5m (Nc)
52- 53 I2 --- N2MASX Number of 2MASX galaxies within the
cluster region (N2MASX)
55- 56 I2 --- Nr Number of galaxies with redshift brighter
than K0s,lim < 15.5m (Nr)
58- 62 I5 km/s cz The mean vhel (Redshift)
64- 66 I3 km/s sigmar Velocity dispersion (σr)
68- 72 F5.2 mag Mmag Magnitude of the brightest cluster galaxy
(m)
74- 77 F4.2 mag AKs The mean value of the foreground
extinction in the region of clusters (AKs)
79- 80 I2 % f The fraction of galaxies with redshift up
to K0s,lim < 15.5m and and within
rc < 1.5 Mpc (f)
82- 85 F4.2 Mpc R200 The radius derived for each cluster using
equation 8 of the section 6 (r200)
87- 89 I3 1/Mpc+2 Density Central number density within 0.1 Mpc
expressed in N.Mpc-2 (Density)
91-102 A12 --- Richness Estimated richness of the cluster based on
velocity dispersion, iso-density maps, and
radial density plots of clusters to compare
them with comparing clusters (Richness) (1)
104-125 A22 --- Structure Structure of clusters based on iso-density
map and the shape of radial density profile
(Structure) (2)
127-129 A3 --- X-ray Flag yes or no for X-ray emission in
0.1-2.4 keV using ROSAT (X-ray) (3)
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Note (1): Intermediate richness of VC02 refers to 3C129- or Virgo-like richness
and Very rich richness of VC04 refers to Coma- or Norma-like richness.
Note (2): VC11 consists of two main clumps as subclusters denoted VC11a and
VC11b.
Note (3): The X-ray luminosity of VC02 refers to LX ∼ 2.6 * 1043 erg/s with
an offset from the centre of ∼19'.50 and the X-ray luminosity of VC04
refers to LX ∼ 5 * 1043 erg/s with an offset from the centre
of ∼30".34.
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Byte-by-byte Description of file: vc0[2458].dat vc1[01].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Cluster Cluster name (Cluster)
6- 28 A23 --- Name Unique identifier designation as
(ZOAhhmmss.sss±ddmmss.ss)
(Designation)
30- 36 F7.3 deg GLON Galactic coordinates l (l)
38- 44 F7.3 deg GLAT Galactic coordinates b (b)
46- 50 F5.3 --- Ell J-band ellipticity epsilon = 1 - (b/a)
(j_ell)
52- 58 F7.3 deg PA [] J-band position angle from East to
North (j_phi)
60- 65 F6.3 arcsec Riso The Ks20 fiducial isophotal radius
rK20fe (r_k20fe)
67- 72 F6.3 mag Jisomag ? J-band K_{s20} fiducial isophotal
magnitude (J_k20fe)
74- 78 F5.3 mag e_Jisomag ? Error of Jisomag (errJ_k20fe)
80- 85 F6.3 mag Hisomag ? H-band K_{s20} fiducial isophotal
magnitude (H_k20fe)
87- 91 F5.3 mag e_Hisomag ? Error of Hisomag (errH_k20fe)
93- 98 F6.3 mag Ksisomag ? K_s-band K_{s20} fiducial isophotal
magnitude (K_k20fe)
100- 104 F5.3 mag e_Ksisomag ? Error of Ksisomag (errK_k20fe)
106- 112 F7.3 mag Jtotmag ? J-band extrapolated total magnitude
(J_tot)
114- 119 F6.3 mag e_Jtotmag ? Error of Jtotmag (errJ_tot)
121- 127 F7.3 mag Htotmag ? H-band extrapolated total magnitude
(H_tot)
129- 134 F6.3 mag e_Htotmag ? Error of Htotmag (errH_tot)
136- 142 F7.3 mag Kstotmag ? K_s-band extrapolated total
magnitude (K_tot)
144- 149 F6.3 mag e_Kstotmag ? Error of Kstotmag (errK_tot)
151- 156 F6.3 mag/arcsec+2 muJ ? J central surface brightness as
µJ = mJ(3") + log(3.02*π)
(mu_J)
158- 163 F6.3 mag/arcsec+2 muH ? H central surface brightness (mu_H)
165- 170 F6.3 mag/arcsec+2 muK ? K_s central surface brightness (mu_K)
172- 176 F5.3 mag E(B-V) E(B-V) galactic reddening along the
line of sight as in Schlegel et al.
1998ApJ...500..525S 1998ApJ...500..525S (ebv)
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Luc Trabelsi [CDS] 26-Jun-2026