J/other/NatAs/2.76 MACSJ1206.2-08474714 clumps photometry (Cava+, 2018)
The nature of giant clumps in distant galaxies probed by the anatomy of
the Cosmic Snake.
Cava A., Schaerer D., Richard J., Perez-Gonzalez P.G.,
Dessauges-Zavadsky M., Mayer L., Tamburello V.
<Nature Astronomy, 2, 76-82 (2018)>
=2018NatAs...2...76C 2018NatAs...2...76C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Gravitational lensing ; Photometry, HST ;
Photometry, ultraviolet ; Optical ; Infrared
Abstract:
Giant stellar clumps are ubiquitous in high-redshift galaxies. They
are thought to play an important role in the build-up of galactic
bulges and as diagnostics of star formation feedback in galactic
discs4. Hubble Space Telescope (HST) blank field imaging surveys have
estimated that these clumps have masses of up to 109.5M☉ and
linear sizes of ∼1kpc. Recently, gravitational lensing has also been
used to get higher spatial resolution. However, both recent lensed
observations and models suggest that the clumps' properties may be
overestimated by the limited resolution of standard imaging
techniques. A definitive proof of this observational bias is
nevertheless still missing. Here we investigate directly the effect of
resolution on clump properties by analysing multiple gravitationally
lensed images of the same galaxy at different spatial resolutions,
down to 30pc. We show that the typical mass and size of giant clumps,
generally observed at ∼1kpc resolution in high-redshift galaxies, are
systematically overestimated. The high spatial resolution data, only
enabled by strong gravitational lensing using currently available
facilities, support smaller scales of clump formation by fragmentation
of the galactic gas disk via gravitational instabilities.
Description:
The multiply imaged galaxy situated behind the central region of the
cluster MACSJ1206.2-08474714 is the perfect target for our experiment.
Using high-quality data from the Cluster Lensing And Supernova survey
with Hubble (CLASH), we have identified clumps in the Cosmic Snake
and the Counterimage starting from the rest-frame UV band (HST-WFC3
filter F390W). We complement this sample by selecting clumps in the
rest-frame optical band (HST-WFC3 filter F110W).
We refer to the two selections as "blue" and "red" clumps
respectively, as the latter have redder SEDs, by definition. We
identify a total of 79 clumps, 24 in the Counterimage and 55 in the
Cosmic Snake (19 in the Northern region, 19 in the Southern region, 10
in the central-Northern region, 7 central-Southern region).
Objects:
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RA (2000) DE Designation(s)
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12 06 12.20 -08 48 02.0 MACS J1206.2-0847471 = MCS J1206.2-0847
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 84 80 Part I. Photometric catalogue
table2.dat 96 80 Part II. Photometric catalogue
table3.dat 35 80 Structural and physical properties of the clumps
table4.dat 34 22 Constraints used for the lensing modelling
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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- 7 A7 --- ID Identification name (G1)
9- 13 F5.2 mag F275W ?=- F275W WFC3 UVIS AB magnitude (1)
15- 18 F4.2 mag e_F275W ? F275W WFC3 UVIS AB magnitude error
20- 24 F5.2 mag F336W ?=- F336W WFC3 UVIS AB magnitude (1)
26- 29 F4.2 mag e_F336W ? F336W WFC3 UVIS AB magnitude error
31- 35 F5.2 mag F390W F390W WFC3 UVIS AB magnitude (1)
37- 40 F4.2 mag e_F390W F390W WFC3 UVIS AB magnitude error
42- 46 F5.2 mag F435W ?=- F435W ACS WFC AB magnitude (1)
48- 51 F4.2 mag e_F435W ? F435W ACS WFC AB magnitude error
53- 57 F5.2 mag F475W F475W ACS WFC AB magnitude (1)
59- 62 F4.2 mag e_F475W F475W ACS WFC AB magnitude error
64- 68 F5.2 mag F606W F606W ACS WFC AB magnitude (1)
70- 73 F4.2 mag e_F606W F606W ACS WFC AB magnitude error
75- 79 F5.2 mag F625W F625W ACS WFC AB magnitude (1)
81- 84 F4.2 mag e_F625W F625W ACS WFC AB magnitude error
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Note (1): The photometry is provided in ABmag system. The listed magnitudes
have been corrected for aperture loss and foreground extinction.
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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- 7 A7 --- ID Identification name (G1)
10- 14 F5.2 mag F775W F775W ACS WFC AB magnitude (1)
16- 19 F4.2 mag e_F775W F775W ACS WFC AB magnitude error
21- 25 F5.2 mag F814W F336W ACS WFC AB magnitude (1)
27- 30 F4.2 mag e_F814W F336W ACS WFC AB magnitude error
32- 36 F5.2 mag F850LP F850LP ACS WFC AB magnitude (1)
38- 41 F4.2 mag e_F850LP F850LP ACS WFC AB magnitude error
43- 47 F5.2 mag F105W F105W WPC3 IR AB magnitude (1)
49- 52 F4.2 mag e_F105W F105W WPC3 IR AB magnitude error
54- 58 F5.2 mag F110W F110W WPC3 IR AB magnitude (1)
60- 63 F4.2 mag e_F110W F110W WPC3 IR AB magnitude error
65- 69 F5.2 mag F125W F125W WPC3 IR AB magnitude (1)
71- 74 F4.2 mag e_F125W F125W WPC3 IR AB magnitude error
76- 80 F5.2 mag F140W F140W WPC3 IR AB magnitude (1)
82- 85 F4.2 mag e_F140W F140W WPC3 IR AB magnitude error
87- 91 F5.2 mag F160W F160W WPC3 IR AB magnitude (1)
93- 96 F4.2 mag e_F160W F160W WPC3 IR AB magnitude error
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Note (1): The photometry is provided in ABmag system. The listed magnitudes
have been corrected for aperture loss and foreground extinction.
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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- 7 A7 --- ID Identification name (G1)
10- 13 F4.2 arcsec amaj Semi-major axis
15- 18 F4.2 arcsec bmin Semi-minor axis
20- 23 I4 pc Rmuc Demagnified equivalent radius (1)
25- 29 F5.2 [Msun] log(Mmud) Demagnified mass (Mmu=Mass/mu)
31- 35 F5.1 --- mue Harmonic average amplification factor
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Note (1): Rmuc=Rvis/SQRT(mu) where the circularized radius, Rvis, is defined
from the semi-axes, a and b, of the elliptical regions as: Rvis = SQRT(a-b).
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- IDc Identification constraints code (1)
5- 6 I2 h RAh Right ascension (J2000) (2)
8- 9 I2 min RAm Right ascension (J2000) (2)
11- 15 F5.2 s RAs Right ascension (J2000) (2)
17 A1 --- DE- Declination sign (J2000) (2)
18- 19 I2 deg DEd Declination (J2000) (2)
21- 22 I2 arcmin DEm Declination (J2000) (2)
24- 28 F5.2 arcsec DEs Declination (J2000) (2)
30- 34 A5 --- xID Cross-identified source name (2)
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Note (1): Individual constraints used in our model for the optimisation of the
cluster mass distribution. Letters A to F refer to matching groups of clumps
identified in the Cosmic Snake (see Figure 8), the correspondence with the
clump ID from Table 3 is provided in the last column.
Note (2): refer to the images of systems 2 and 3 to the East of the cluster,
spectroscopically confirmed at z=3.038.
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Global notes:
Note (G1): Identifiers are:
CI-all for Counterimage
CI-RN for Counterimage, red sources
CI-a for Counterimage, blue sources
Cn-RN for Central-north, red sources
Cn-a for Central-north, blue sources
Cs-RN for Central-south, red sources
Cs-a for Central-south, blue sources
Sn-RN for Cosmic Snake-north, red sources
Sn-a for Cosmic Snake-north, blue sources
Ss-RN for Cosmic Snake-south, red sources
SS-a for Cosmic Snake-south, blue sources
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 05-Aug-2023