J/MNRAS/508/1206 Galaxy clusters redshifts with VLT/MUSE (Jauzac+, 2021)
Galaxy cluster cores as seen with VLT/MUSE New strong-lensing analyses of
RX J2129.4 + 0009, MS 0451.6 - 0305, and MACS J2129.4 - 0741.
Jauzac M., Klein B., Kneib J.-P., Richard J., Rexroth M., Schafer C.,
Verdier A.
<Mon. Not. R. Astron. Soc. 508, 1206-1226 (2021)>
=2021MNRAS.508.1206J 2021MNRAS.508.1206J (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Gravitational lensing ; Spectrophotometry ;
Optical ; Infrared ; Positional data ; Redshifts
Keywords: gravitational lensing: strong - Techniques: imaging spectroscopy -
Galaxies: clusters: general - Galaxies: clusters: individual
(RX J2129.4+0009, MS 0451.6-0305, MACS J2129.4-0741)
Abstract:
We present strong-lensing analyses of three galaxy clusters,
RX J2129.4 + 0009 (z = 0.235), MS 0451.6 - 0305 (z = 0.55), and
MACS J2129.4 - 0741 (z = 0.589), using the powerful combination of
Hubble Space Telescope (HST) multiband observations, and Multi-Unit
Spectroscopic Explorer (MUSE) spectroscopy. In RX J2129, we newly
spectroscopically confirm 15 cluster members. Our resulting mass model
uses 8 multiple image systems as we include a galaxy-galaxy lensing
system north-east of the cluster, and is composed of 71 haloes
including one dark matter cluster-scale halo and two galaxy-scale
haloes optimized individually. For MS 0451, we report the
spectroscopic identification of two new systems of multiple images in
the northern region and 112 cluster members. Our mass model uses 16
multiple image systems and 146 haloes, including 2 large-scale haloes
and 7 galaxy-scale haloes independently optimized. For MACS J2129, we
report the spectroscopic identification of one new multiple image
system at z = 4.41, and newly measure spectroscopic redshifts for four
cluster members. Our mass model uses 14 multiple image systems, and is
composed of 151 haloes, including 2 large-scale haloes and 4
galaxy-scale haloes independently optimized. Our best models have rms
of 0.29, 0.6, 0.74 arcsec in the image plane for RX J2129, MS 0451,
and MACS J2129, respectively. This analysis presents a detailed
comparison with the existing literature showing excellent agreements,
and discuss specific studies of lensed galaxies, e.g. a group of
submillimetre galaxies at z = 2.9 in MS 0451, and a bright z = 2.1472
red singly imaged galaxy in MACS J2129.
Description:
We present MUSE observations, and their subsequent strong-lensing
analyses, for three well-known galaxy clusters: RX J2129.4 + 0009,
MS0451.6 - 0305, and MACS J2129.4 - 0741. These clusters have been
observed with HST, and already have strong-lensing mass models
published in the literature (more details are given bellow, but e.g.
Richard et al. 2010MNRAS.404..325R 2010MNRAS.404..325R, Cat. J/MNRAS/404/325; Zitrin et
al. 2011ApJ...742..117Z 2011ApJ...742..117Z, Zitrin et al. 2015ApJ...801...44Z 2015ApJ...801...44Z, Cat.
J/ApJ/801/44; MacKenzie et al. 2014MNRAS.445..201M 2014MNRAS.445..201M; Monna et al.
2017MNRAS.466.4094M 2017MNRAS.466.4094M; Caminha et al. 2019A&A...632A..36C 2019A&A...632A..36C, Cat.
J/A+A/632/A36) which are used as references in this analysis, and
referred to as fiducial models in the rest of this study).
RX J2129, MS 0451, and MACS J2129 were observed with MUSE on the VLT
and the data were reduced with version 1.6.4 of the standard MUSE
pipeline (Weilbacher et al. 2014ASPC..485..451W 2014ASPC..485..451W, Weilbacher et al.
2020A&A...641A..28W 2020A&A...641A..28W). We carry out wavelength, geometrical and
astrometric calibrations in order to assign the World Coordinate
System (WCS) right ascension and declination, and the wavelength to
each pixel of the datacube. We apply the Zurich Atmosphere Purge (zap;
Soto et al. 2016MNRAS.458.3210S 2016MNRAS.458.3210S) software version 1.0, which uses a
principal components analysis to analyse objects-free regions in the
datacube and subtract systematics due to sky subtraction residuals. To
create the zap objects mask, we use the segmentation map obtained by
applying the SEXTRACTOR software (Bertin & Arnouts
1996A&AS..117..393B 1996A&AS..117..393B) on a white-light image collapsing the datacube
along its wavelength axis. The wavelength range of the final datacube
stretches from 4750 to 9350 Å in steps of 1.25 Å, and the spaxel
size is 0.2 arcsec, (see section 2.1 Observations and data reduction).
During the spectra extraction (see section 2.2 Spectrum extraction),
we use the python data analysis algorithm MUSELET
(http://mpdaf.readthedocs.io/en/latest/muselet.html) to maximize the
number of extracted spectra. Thus, we extract a catalogue of sources
with their associated set of spectra used to computed redshifts. As
explained the section 2.3 Redshift measurements with the help of
IFS-REDEX software, an interactive interface displays each extracted
spectrum and its corresponding source in SAODS9 (Joye & Mandel
2003ASPC..295..489J 2003ASPC..295..489J). It allows us to modify the source redshift to
match the position of an emission/absorption line template to its most
likely position in the spectrum. The template contains about 60 lines
including notably Ly α, [O II], [O III], and H β emission
lines, and Ca H&K, Mg, Fe, and Na absorption lines. For each redshift,
we assign a quality flag (QF) of 3 if the redshift is secure, 2 if
likely (e.g. only one characteristic line - for example the [O II]
doublet or Ly α line with consistent photometric redshift), 1 if
insecure, and 0 otherwise, i.e. in case of visually flat continuum or
highly polluted spectrum.
Thus, we sequentially analyse all spectra extracted from the MUSE
datacubes of the three clusters using the aforementioned method. The
measured redshifts are sorted depending on whether they belong to a
source located in the foreground of the cluster, in the cluster, or in
the background. We thus obtain three tables, the
tablea1.dat,tablea2.dat and tablea3.dat.
As detailed in the section 2.4 Results of the redshift extraction, for
the cluster RX J2129 we extracted 158 sources with redshifts ranging
from 0.0 to 5.53. Among them, 43 are identified as cluster members
with 0.2145 < z < 0.2410, 24 as foreground objects, and 91 as
background sources, (i.e section 2.4.1 RX J2129). For the cluster MS
0451, we extracted 171 sources with redshifts ranging from 0.0 to 4.85
from the MUSE datacube. Among them, 112 are identified as cluster
members, with 0.5307 < z < 0.5652, 24 sources are identified as
foreground objects, 35 are identified as background sources, (i.e
section 2.4.2 MS 0451). Finally, for the cluster MACS J2129, we
extracted 189 sources with redshifts ranging from 0.0 to 4.92. Among
them, 89 are identified as cluster members with 0.5737 < z < 0.6032,
39 as foreground objects, and 61 as background sources, (i.e section
2.4.3 MACS J2129). Allowing us to compare our results to those
reported in Caminha et al. (2019A&A...632A..36C 2019A&A...632A..36C, Cat. J/A+A/632/A36)
to detect new and miss redshifts measurements.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 42 156 List of redshifts measured with a quality flag
larger than 2 in RX J2129.4 + 0009
tablea2.dat 43 162 List of redshifts measured with a quality flag
larger than 2 in MS 0451.6 - 0305
tablea3.dat 41 195 List of redshifts measured with a quality flag
larger than 2 in MACS J2129.4 - 0741
--------------------------------------------------------------------------------
See also:
J/MNRAS/404/325 : Massive galaxy clusters lensing analyse (Richard+, 2010)
J/ApJ/801/44 : HST lensing analysis of the CLASH sample (Zitrin+, 2015)
J/A+A/632/A36 : Strong lensing models of 8 CLASH clusters (Caminha+, 2019)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- ID Name identifier (ID) (G1)
10- 18 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000)
20- 26 F7.5 deg DEdeg Declination in decimal degrees (J2000)
28- 33 F6.4 --- z Redshift of the source (z)
35- 40 F6.4 10-4 e_z Systematic error on z in unit of 10-4
(zerr*10-4)
42 I1 --- QF Quality flag on redshift (QF) (G2)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- ID Name identifier (ID) (G1)
11- 19 F9.6 deg RAdeg Right Ascension in decimal degrees (J2000)
21- 28 F8.5 deg DEdeg Declination in decimal degrees (J2000)
30- 36 F7.4 --- z Redshift of the source (z)
38- 41 F4.2 10-4 e_z Systematic error on z in unit of 10-4
(zerr*10-4)
43 I1 --- QF Quality flag on redshift (QF) (G2)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- ID Name identifier (ID) (G1)
8- 17 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
19- 26 F8.5 deg DEdeg Declination in decimal degrees (J2000)
28- 34 F7.4 --- z Redshift of the source (z)
36- 39 F4.2 10-4 e_z Systematic error on z in unit of 10-4
(zerr*10-4)
41 I1 --- QF Quality flag on redshift (QF) (G2)
--------------------------------------------------------------------------------
Global notes:
Note (G1): The sing and cont stand for singular and continuum emission line in
the muselet catalogue. If it exists, the index stands for the
pointing's number.
Note (G2): For each redshift, we assign a quality flag (QF) as follows:
3 = if the redshift is secure
2 = if likely (e.g. only one characteristic line - for example
the [O II] doublet or Ly α line with consistent photometric
redshift)
1 = if insecure
0 = otherwise (i.e. in case of visually flat continuum or highly
polluted spectrum)
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 30-Jul-2024