J/MNRAS/485/3738 3D structure in the A370 MUSE Mosaic (Lagattuta+, 2019)
Probing 3D structure with a large MUSE mosaic: extending the mass model of
Frontier Field Abell 370.
Lagattuta D.J., Richard J., Bauer F.E., Clement B., Mahler G., Soucail G.,
Carton D., Kneib J.-P., Laporte N., Martinez J., Patricio V., Payne A.V.,
Pello R., Schmidt K.B., de la Vieuville G.
<Mon. Not. R. Astron. Soc., 485, 3738-3760 (2019)>
=2019MNRAS.485.3738L 2019MNRAS.485.3738L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Gravitational lensing ; Redshifts ;
Photometry, HST ; Models
Keywords: gravitational lensing: strong - techniques: imaging spectroscopy -
galaxies: clusters: individual: Abell 370 - galaxies: high-redshift -
dark matter - large-scale structure of Universe
Abstract:
We present an updated strong-lensing analysis of the massive cluster
Abell 370 (A370), continuing the work first presented in L17. In this
new analysis, we take advantage of the deeper imaging data from the
Hubble Space Telescope Frontier Fields programme, as well as a large
spectroscopic mosaic obtained with the Multi-Unit Spectroscopic
Explorer (MUSE). Thanks to the extended coverage of this mosaic, we
probe the full 3D distribution of galaxies in the field, giving us a
unique picture of the extended structure of the cluster and its
surroundings. Our final catalogue contains 584 redshifts, representing
the largest spectroscopic catalogue of A370 to date. Constructing the
model, we measure a total mass distribution that is quantitatively
similar to our previous work - though to ensure a low rms error in the
model fit, we invoke a significantly large external shear term. Using
the redshift catalogue, we search for other bound groups of galaxies,
which may give rise to a more physical interpretation of this shear.
We identify three structures in narrow redshift ranges along the line
of sight, highlighting possible infalling substructures into the main
cluster halo. We also discover additional substructure candidates in
low-resolution imaging at larger projected radii. More spectroscopic
coverage of these regions (pushing close to the A370 virial radius)
and more extended, high-resolution imaging will be required to
investigate this possibility, further advancing the analysis of these
interesting developments.
Description:
These catalogs contain observational and model-dependent data for
objects within and along the line of sight of the Abell 370 galaxy
cluster. MUSE data are acquired in Wide-field, non-AO mode (WFM-NOAO)
using both Guaranteed Time Observations (GTO) and General Observer
(GO) time. The Frontier Fields images used to measure photometry and
astrometry are publicly available at
[https://archive.stsci.edu/prepds/frontier/]. All magnitudes are
presented in the AB system. Lens model parameters are generated with
the LENSTOOL software package (Kneib et al. 1996ApJ...471..643K 1996ApJ...471..643K; Jullo
et al. 2007NJPh....9..447J 2007NJPh....9..447J; Jullo & Kneib 2009MNRAS.395.1319J 2009MNRAS.395.1319J)
available at the following location:
[https://projets.lam.fr/projects/lenstool/wiki]. The potentials used
to construct the lens models are based on the dual Pseudo-Isothermal
Ellipsoid density profile presented in Eliasdottir et al.
2007arXiv0710.5636E 2007arXiv0710.5636E.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 55 138 Multiply imaged systems
tablea1a.dat 58 6 Lens Models (goodness-of-fit statistics)
tablea1b.dat 160 72 Lens Models (best-fit model parameters)
tablec1.dat 309 584 Master MUSE Redshift Catalog
tabled1.dat 642 30 MUSE-GLASS Redshift Comparisons
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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- 4 F4.1 --- mID Multiple Image ID
([LRC2017] A370 NN.N in Simbad)
6- 14 F9.6 deg RAdeg Right ascension (J2000)
16- 25 F10.7 deg DEdeg Declination (J2000)
27- 32 F6.4 --- zspec ? Spectroscopic redshift (1)
34- 38 F5.3 --- zmod ? Lens model predicted redshift (2)
40- 44 F5.3 --- e_zmod ? Error on zmod
46- 51 A6 --- Class Multiple Image constraint class (3)
53- 55 A3 --- Note ?=- Notes on specific Multiple Images (4)
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Note (1): Unless otherwise specified (i.e. a measurement having fewer than four
significant digits), spectroscopic redshifts have an uncertainty
δz=±0.0001
Note (2): Redshifts fitted by the model as free parameters
Note (3): 'Quality' flag of the Multiple Image constraint, based on the Hubble
Frontier Fields Public Modeling Challenge discussion. Constraints can
be labeled 'gold', 'silver', 'bronze', or 'copper', with gold
constraints being the most reliable, and copper the most uncertain.
Note (4): Notes as follows:
1 = These systems are not used as constraints in our mass model. Our
best-fitting solution merges Image 10.1 and 10.2 into a single
constraint, while Image 16.2 is predicted but is not seen in either
MUSE or HST data
2 = While originally identified as unique systems, updated modelling
suggests they are in fact counterimages of other objects
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Byte-by-byte Description of file: tablea1a.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Model Lens model name
20- 22 I3 --- n Total number of model constraints
24- 25 I2 --- k Total number of model parameters
27- 30 F4.2 arcsec rms Best-fit model rms error
32- 35 F4.2 --- chi2 Best-fit model chi-squared per degree of
freedom
37- 43 F7.2 [-] loglike Best-fit model log(likelihood) value
45- 51 F7.2 [-] logevid Best-fit model log(evidence) value
53- 58 F6.2 --- BIC Best-fit model Bayesian Information Criteria
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Byte-by-byte Description of file: tablea1b.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Model Lens model name
20- 38 A19 --- Comp Model component name
40- 45 F6.2 arcsec dRA ? Relative right ascension (1)
47 A1 --- f_dRA Flag on dRA (2)
49- 52 F4.2 arcsec E_dRA ? Upper error on dRA
54- 57 F4.2 arcsec e_dRA ? Lower error on dRA
59- 63 F5.2 arcsec dDE ? Relative declination (1)
65 A1 --- f_dDE Flag on dDE (2)
67- 70 F4.2 arcsec E_dDE ? Upper error on dDE
72- 75 F4.2 arcsec e_dDE ? Lower error on dDE
77- 81 F5.3 --- ell ? Ellipticity (or shear magnitude) (3)
83 A1 --- f_ell Flag on ell (2)
85- 89 F5.3 --- E_ell ? Upper error on ell
91- 95 F5.3 --- e_ell ? Lower error on ell
97-102 F6.1 deg PA []? Position angle (East of North)
104 A1 --- f_PA Flag on PA (2)
106-108 F3.1 deg E_PA ? Upper error on PA
110-112 F3.1 deg e_PA ? Lower error on PA
114-119 F6.2 kpc rCore ? Core radius of dPIE potential
121 A1 --- f_rCore Flag on rCore (2)
123-126 F4.1 kpc E_rCore ? Upper error on rCore
128-131 F4.1 kpc e_rCore ? Lower error on rCore
133-137 F5.1 kpc rCut ? Cut radius of dPIE potential
139 A1 --- f_rCut Flag on rCut (2)
141-144 F4.1 kpc E_rCut ? Upper error on rCut
146-149 F4.1 kpc e_rCut ? Lower error on rCut
151-154 I4 km/s sig0 ? Central velocity dispersion of potential
156-157 I2 km/s E_sig0 ? Upper error on sig0
159-160 I2 km/s e_sig0 ? Lower error on sig0
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Note (1): dRA and dDE are measured relative to the reference coordinate point:
(39.97134, -1.5822597)
Note (2): Flag as follows:
* = Component parameters without uncertainties are fixed quantities and do
not vary in the model
Note (3): Ellipticity is defined as ell=(a2-b2)/(a2+b2), where a and b
are the semi-major and semi-minor axes of the ellipse, respectively
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Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- ID Object ID (1)
7- 16 F10.7 deg RAdeg Right ascension (J2000)
18- 27 F10.7 deg DEdeg Declination (J2000)
29- 34 F6.4 --- z MUSE redshift
36 I1 --- Type Spectroscopic type flag (2)
38 I1 --- Conf Spectroscopic confidence flag (3)
40- 46 F7.3 mag F435Wmag ?=99.0 AB Magnitude (apparent) in F435W
filter (4)
48- 53 F6.3 mag e_F435Wmag ?=99.0 Mean error on F435Wmag
55- 61 F7.3 mag F606Wmag ?=99.0 AB Magnitude (apparent) in F606W
filter (4)
63- 68 F6.3 mag e_F606Wmag ?=99.0 Mean error on F606Wmag
70- 76 F7.3 mag F814Wmag ?=99.0 AB Magnitude (apparent) in F814W
filter (4)
78- 83 F6.3 mag e_F814Wmag ?=99.0 Mean error on F814Wmag
85- 91 F7.3 mag F105Wmag ?=99.0 AB Magnitude (apparent) in F105W
filter (4)
93- 98 F6.3 mag e_F105Wmag ?=99.0 Mean error on F105Wmag
100-106 F7.3 mag F125Wmag ?=99.0 AB Magnitude (apparent) in F125W
filter (4)
108-113 F6.3 mag e_F125Wmag ?=99.0 Mean error on F125Wmag
115-121 F7.3 mag F140Wmag ?=99.0 AB Magnitude (apparent) in F140W
filter (4)
123-128 F6.3 mag e_F140Wmag ?=99.0 Mean error on F140Wmag
130-136 F7.3 mag F160Wmag ?=99.0 AB Magnitude (apparent) in F160W
filter (4)
138-143 F6.3 mag e_F160Wmag ?=99.0 Mean error on F160Wmag
145-152 F8.3 --- mu Lensing magnification (5)
154-162 F9.3 --- e_mu Mean error on mu
164-172 A9 --- mID ? Multiply-Imaged object ID (6)
174-309 A136 --- lines Summary of features seen in MUSE spectrum
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Note (1): Objects labeled with the letter M (e.g., M11) are only detected in
MUSE data. They show no signs of continuum emission in any of the
HST images.
Note (2): Spectroscopic type as follows:
0 = Star
1 = Hα emitter (z<0.4)
2 = [OII] emitter (0.4<z<1.5)
3 = Absorption-line galaxy (typically cluster members)
4 = [CIII] emitter (1.5<z<3.0)
5 = Lyman α emitter (z>3.0)
6 = [OIII] emitter (only if Hα and [OII] not present; very rare)
Note (3): Spectroscopic confidence as follows:
3 = Secure redshift; multiple prominent spectral features or one strong
feature (such as Lyman α) that is unambiguous to identify.
2 = Probable redshift; features are less strong but still clearly
identifiable. They may be overly broad or noisy, leading to a less
precise peak (or trough) estimate. The redshift precision is still
less than δz=0.001
1 = Possible redshift; identified by one (ambiguous) line feature, or
a few, very low S/N lines. Often faint absorption-line galaxies.
These redshifts should be used with caution.
Note (4): A negative magnitude value (e.g., -12.345) means that the object is
not detected in this band. Instead, the (positive) number represents
the 3σ detection limit, effectively placing an upper bound on
the galaxy's flux.
In addition, two other 'flag' values highlight further photometric
errors, as follows:
-1.0 = 'No Data' -- Object does not fall in the HST FoV in this filter.
-2.0 = 'Anomaly' -- Object photometry is contaminated by a systematic
anomaly in this band, such as cosmic ray or hot pixel.
Note (5): Magnification values are calculated using the Copper lens model.
Note (6): A single object may contain two multiple-image IDs if it is identified
as a merging pair of images.
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Byte-by-byte Description of file: tabled1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- IDMUSE Object ID in MUSE catalog
7- 12 F6.4 --- zMUSE MUSE redshift
14 I1 --- cMUSE MUSE spectroscopic confidence flag
16 I1 --- cMUSEnew ? Updated MUSE spectroscopic confidence flag
18- 21 I4 --- IDGLASS Object ID in GLASS catalog
23- 28 F6.3 --- zGLASS ?=-1 GLASS redshift (1)
30- 34 F5.3 --- zGLASSnew ? Updated GLASS redshift
36- 38 F3.1 --- cGLASS GLASS spectroscopic confidence flag
40 I1 --- cGLASSnew ? Updated GLASS spectroscopic confidence flag
42-642 A601 --- Comments Summary of the comparison between MUSE and
GLASS data
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Note (1): -1.0 = No redshift measurement in the GLASS catalogue
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 27-Sep-2022