J/MNRAS/460/2193 A3407 + A3408 radial velocities (Nascimento+, 2016)
Dynamical analysis of the cluster pair: A3407 + A3408.
Nascimento R.S., Ribeiro A.L.B., Trevisan M., Carrasco E.R., Plana H.,
Dupke R.
<Mon. Not. R. Astron. Soc., 460, 2193-2206 (2016)>
=2016MNRAS.460.2193N 2016MNRAS.460.2193N (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Radial velocities
Keywords: galaxies: clusters: general -
galaxies: clusters: intracluster medium - galaxies: evolution -
galaxies: statistics
Abstract:
We carried out a dynamical study of the galaxy cluster pair A3407 and
A3408 based on a spectroscopic survey obtained with the 4 metre Blanco
telescope at the Cerro Tololo Interamerican Observatory, plus 6dF
data, and ROSAT All-Sky Survey. The sample consists of 122 member
galaxies brighter than mR=20. Our main goal is to probe the galaxy
dynamics in this field and verify if the sample constitutes a single
galaxy system or corresponds to an ongoing merging process.
Statistical tests were applied to clusters members showing that both
the composite system A3407 + A3408 as well as each individual cluster
have Gaussian velocity distribution. A velocity gradient of
∼847±114km/s was identified around the principal axis of the
projected distribution of galaxies, indicating that the global field
may be rotating. Applying the kmm algorithm to the distribution of
galaxies, we found that the solution with two clusters is better than
the single unit solution at the 99 per cent cl. This is consistent
with the X-ray distribution around this field, which shows no common
X-ray halo involving A3407 and A3408. We also estimated virial masses
and applied a two-body model to probe the dynamics of the pair. The
more likely scenario is that in which the pair is gravitationally
bound and probably experiences a collapse phase, with the cluster
cores crossing in less than ∼1h-1Gyr, a pre-merger scenario. The
complex X-ray morphology, the gas temperature, and some signs of
galaxy evolution in A3408 suggest a post-merger scenario, with cores
having crossed each other ∼1.65h-1Gyr ago, as an alternative
solution.
Description:
All images and spectroscopic data of Abell 3407 and Abell 3408 were
collected with the 4 metre Victor Blanco telescope at the Cerro Tololo
Interamerican Observatory (CTIO), in Chile. The clusters were imaged
through the B, V and R Johnson-Cousins filters with the Mosaic II
CCD imager during the nights of 2007 February 14 and 15.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 84 67 Abell 3407
tablea2.dat 82 38 Abell 3408
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Byte-by-byte Description of file: tablea1.dat tablea2.dat
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Bytes Format Units Label Explanations
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1 I1 h RAh Right ascension (J2000)
3- 4 I2 min RAm Right ascension (J2000)
6- 10 F5.2 s RAs Right ascension (J2000)
12 A1 --- DE- Declination sign (J2000)
13- 14 I2 deg DEd Declination (J2000)
16- 17 I2 arcmin DEm Declination (J2000)
19- 22 F4.1 arcsec DEs Declination (J2000)
24- 28 F5.2 mag Rmag Cousins R magnitude
30- 34 I5 km/s RV Radial velocity
36- 38 I3 km/s e_RV rms uncertainty on RV
40- 44 F5.2 --- R R parameter (Tonry & Davis, 1979AJ.....84.1511T 1979AJ.....84.1511T)
46- 84 A39 --- EmLines Emission lines
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 27-Oct-2017