J/MNRAS/492/2405 A spectroscopic survey of Abell 1703 (Boschin+, 2020)
A spectroscopic survey of Abell 1703: is it a rare relaxed cluster hosting a
radio halo or a usual merging system?
Boschin W., Girardi M., Gastaldello F.
<Mon. Not. R. Astron. Soc., 492, 2405-2417 (2020)>
=2020MNRAS.492.2405B 2020MNRAS.492.2405B (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Positional data ; Radial velocities ;
Spectra, optical ; Photometry, SDSS
Keywords: galaxies: clusters: general -
galaxies: clusters: individual: Abell 1703 -
galaxies: kinematics and dynamics
Abstract:
We present the study of the internal dynamics of the intriguing galaxy
cluster Abell 1703, a system hosting a probable giant radio halo whose
dynamical status is still controversial. Our analysis is based on
unpublished spectroscopic data acquired at the Italian Telescopio
Nazionale Galileo and data publicly available in the literature. We
also use photometric data from the Sloan Digital Sky Survey. We select
147 cluster members and compute the cluster redshift ∼0.277 and the
global line-of-sight velocity dispersion σv∼1300km/s. We infer
that Abell 1703 is a massive cluster: M200∼1-2x1015M☉. The
results of our study disagree with the picture of an unimodal, relaxed
cluster as suggested by previous studies based on the gravitational
lensing analysis and support the view of a perturbed dynamics proposed
by recent works based on Chandra X-ray data. The first strong evidence
of a dynamically disturbed cluster comes from the peculiarity of the
BCG velocity with respect to the first moment of the velocity
distribution of member galaxies. Moreover, several statistical tests
employed to study the cluster galaxies kinematics find significant
evidence of substructure, being Abell 1703 composed by at least two or
three subclumps probably caught after the core-core passage. In this
observational scenario, the suspected existence of a radio halo in the
centre of this cluster is not surprising and well agrees with the
theoretical models describing diffuse radio sources in clusters.
Description:
We used unpublished spectroscopic data stored in the TNG archive
(http://archives.ia2.inaf.it/tng) taken in 2010 May (program
A21TAC_50; PI: F. Gastaldello). These data consist of five MOS masks
mainly sampling the central region of the cluster. Another mask was
taken in 2016 June during a technical night. In particular, this last
mask allowed us to obtain the spectrum of the brightest cluster galaxy
(BCG). For all the six masks we used the LR-B Grism of the instrument
DOLoRes (http://www.tng.iac.es/instruments/lrs) and obtained spectra
for 131 objects. The total exposure times varied from 3600 to 7200s.
In order to extend our spectroscopic sample to the outskirts of the
cluster, we searched the NED data base for galaxies with known
redshift in the field of Abell 1703. We found 184 objects within a
radius of ∼20arcmin from the cluster centre. Most of these objects
(177) come from Bayliss et al. (2014ApJ...783...41B 2014ApJ...783...41B), ten of which are
in common with our TNG data.
Our final spectroscopic catalogue includes 278 galaxies. The field of
Abell 1703 is covered by the SDSS. Its galaxy catalogue also provides
us complete photometric information for all the galaxies of the
spectroscopic sample in the magnitude bands g, r, and i.
Objects:
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RA (ICRS) DE Designation(s)
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13 15 05.19 +51 49 02.0 Abell 1703 = 1RXS J131506.8+514931
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 50 278 Velocity catalogue of 278 spectroscopically
measured galaxies in the field of Abell 1703
table2.dat 35 2 Substructures detected by the analysis of the
2D distribution of the spectroscopic members of
Abell 1703
table3.dat 22 4 Substructures detected by the 3D analysis of
the spectroscopic members of Abell 1703
(Htree method)
table4.dat 26 2 Substructures detected by the 3D analysis of
the spectroscopic members of Abell 1703
(3D-KMM method)
table5.dat 44 3 Substructures detected by the 3D analysis of
the spectroscopic members of Abell 1703
(3D-DEDICA method)
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [001/278] Galaxy identification number
5 A1 --- f_ID Flag on ID (1)
7 A1 --- Source [BTL] Redshift source (2)
9- 10 I2 h RAh Right ascension (J2000)
12- 13 I2 min RAm Right ascension (J2000)
15- 19 F5.2 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
25- 26 I2 arcmin DEm Declination (J2000)
28- 31 F4.1 arcsec DEs Declination (J2000)
33- 37 F5.2 mag rmag Dereddened SDSS r-band magnitude
39- 44 I6 km/s RV Heliocentric radial velocity RV=cz☉
46- 48 I3 km/s e_RV Error on RV
50 A1 --- feRV [e] Flag on e_RV (3)
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Note (1): Flag as follows:
a = Non-member galaxies
b = Galaxy 141 is the brightest cluster galaxy (BCG)
Note (2): Redshift source as follows:
B = Bayliss et al. (2014ApJ...783...41B 2014ApJ...783...41B)
L = NED Data base
T = Spectroscopic data obtained at the Italian Telescopio Nazionale Galileo
(TNG)
Note (3): Flag as follows:
e = Redshift computed by measuring the wavelengths of the emission lines in
the spectrum
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 A1 --- ID [NS] Subclump identifier
3- 4 I2 --- NS Number of assigned member galaxies
6- 7 I2 h RAh Right ascension (J2000)
9- 10 I2 min RAm Right ascension (J2000)
12- 15 F4.1 s RAs Right ascension (J2000)
17 A1 --- DE- Declination sign (J2000)
18- 19 I2 deg DEd Declination (J2000)
21- 22 I2 arcmin DEm Declination (J2000)
24- 25 I2 arcsec DEs Declination (J2000)
27- 30 F4.2 --- rhos Relative density with respect to the densest
subclump
32- 35 F4.1 --- chi2s χ2 value of the galaxy peak
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- ID Subclump identifier (GNN)
5- 6 I2 --- NS Number of assigned member galaxies
8- 12 I5 km/s RV Mean radial velocity
14- 15 I2 km/s e_RV Error on RV
17- 19 I3 km/s sigma Radial velocity dispersion
21- 22 I2 km/s e_sigma Error on sigma
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- ID Subclump identifier (KMM3DN)
8- 9 I2 --- NS Number of assigned member galaxies
11- 15 I5 km/s RV Mean radial velocity
17- 19 I3 km/s e_RV Error on RV
21- 23 I3 km/s sigma Radial velocity dispersion
25- 26 I2 km/s e_sigma Error on sigma
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- ID Subclump identifier (DED3DN)
8- 9 I2 --- NS Number of assigned member galaxies
11- 15 I5 km/s RVfit Fitted radial velocity
17- 18 I2 h RAh Right ascension (J2000)
20- 21 I2 min RAm Right ascension (J2000)
23- 26 F4.1 s RAs Right ascension (J2000)
28 A1 --- DE- Declination sign (J2000)
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 36 I2 arcsec DEs Declination (J2000)
38- 41 F4.2 --- rhos Relative density with respect to the densest
subclump
43- 44 I2 --- chi2s χ2 value of the galaxy peak
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 20-Mar-2023