J/A+A/642/A148 SuGOHI VI. List up to 2020 (Sonnenfeld+, 2020)
Survey of Gravitationally-lensed Objects in HSC Imaging (SuGOHI).
VI. Crowdsourced lens finding with Space Warps.
Sonnenfeld A., Verma A., More A., Beaten E., Macmillan C., Wong K.C.,
Chan J.H.H., Jaelani A.T., Lee C., Oguri M., Rusu C.E., Veldthuis M.,
Trouille L., Marshall P.J., Hutchings R., Allen C., O' Donnell J.,
Cornen C., Davis C.P., McMaster A., Lintott C., Miller G.
<Astron. Astrophys. 642, A148 (2020)>
=2020A&A...642A.148S 2020A&A...642A.148S (SIMBAD/NED BibCode)
ADC_Keywords: Gravitational lensing ; Redshifts
Keywords: gravitational lensing: strong -
galaxies: elliptical and lenticular, cD
Abstract:
Strong lenses are extremely useful probes of the distribution of
matter on galaxy and cluster scales at cosmological distances, but are
rare and difficult to find. The number of currently known lenses is on
the order of 1000.
We wish to use crowdsourcing to carry out a lens search targeting
massive galaxies selected from over 442 square degrees of photometric
data from the Hyper Suprime-Cam (HSC) survey.
We selected from the S16A internal data release of the HSC survey a
sample of ∼300000 galaxies with photometric redshifts in the range
0.2<zphot<1.2 and photometrically inferred stellar masses logM*>11.2.
We crowdsourced lens finding on this sample of galaxies on the
Zooniverse platform, as part of the Space Warps project. The sample
was complemented by a large set of simulated lenses and visually
selected non-lenses, for training purposes. Nearly 6000 citizen
volunteers participated in the experiment. In parallel, we used
YattaLens an automated lens finding algorithm, to look for lenses in
the same sample of galaxies.
Based on a statistical analysis of classification data from the
volunteers, we selected a sample of the most promising ∼1500
candidates which we then visually inspected: half of them turned out
to be possible (grade C) lenses or better. Including lenses found by
YattaLens or serendipitously noticed in the discussion section of the
Space Warps website, we were able to find 14 definite lenses
(grade A), 129 probable lenses (grade B) and 581 possible lenses.
YattaLens found half the number of lenses discovered via
crowdsourcing.
Crowdsourcing is able to produce samples of lens candidates with high
completeness and purity, compared to currently available automated
algorithms. A hybrid approach, in which the visual inspection of
samples of lens candidates pre-selected by discovery algorithms and/or
coupled to machine learning is crowdsourced, will be a viable option
for lens finding in the 2020s with forthcoming wide area surveys such
as LSST, Euclid and WFIRST.
Description:
Catalog of strong lenses and strong lens candidates originally
discovered in HSC data, or present in HSC data and used in a strong
lensing study as part of the Survey of Gravitationally-lensed Objects
in HSC Imaging (SuGOHI), up to and including the SuGOHI VI paper,
published in 2020.
This includes lenses published in Tanaka et al. (2015ApJ...801...20T 2015ApJ...801...20T),
More et al. (2017MNRAS.465.2411M 2017MNRAS.465.2411M), Sonnenfeld et al.
(2018PASJ...70S..29S 2018PASJ...70S..29S, SuGOHI I), Wong et al. (2018ApJ...867..107W 2018ApJ...867..107W,
SuGOHI II), Sonnenfeld et al. (2019A&A...630A..71S 2019A&A...630A..71S, SuGOHI III), Chan
et al. (2020A&A...636A..87C 2020A&A...636A..87C, SuGOHI IV), Jaelani et al.
(2020MNRAS.494.3156J 2020MNRAS.494.3156J), Jaelani et al. (2020MNRAS.495.1291J 2020MNRAS.495.1291J, SuGOHI V),
Sonnenfeld et al. (2020, SuGOHI VI, this paper).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sugohi.dat 71 2000 SuGOHI catalog
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Byte-by-byte Description of file: sugohi.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Name Designation (HSCJHHMMSS.ss+DDMMSS.s)
24- 32 F9.5 deg RAdeg Right Ascension (J2000)
35- 42 F8.5 deg DEdeg Declination (J2000)
44- 49 F6.3 --- zl ?=-9.999 Lens spectroscopic redshift
(set to -9.999 when unavailable)
51- 56 F6.3 --- zs ?=-9.999 Source spectroscopic redshift
(set to -9.999 when unavailable)
58- 63 F6.3 --- pzl ?=-9.999 Lens photometric redshift
(set to -9.999 when unavailable)
65 A1 --- Grade [ABC] Lens probability (1)
67- 71 A5 --- Ref SuGOHI paper reference (2)
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Note (1): Lens probability as follows:
A = definitely
B = probably
C = possibly
Note (2): SuGOHI paper reference as follows:
a = Tanaka et al. (2015ApJ...801...20T 2015ApJ...801...20T)
b = More et al. (2017MNRAS.465.2411M 2017MNRAS.465.2411M)
c = Sonnenfeld et al. (2018PASJ...70S..29S 2018PASJ...70S..29S, SuGOHI I)
d = Wong et al. (2018ApJ...867..107W 2018ApJ...867..107W, SuGOHI II)
e = Sonnenfeld et al. (2019A&A...630A..71S 2019A&A...630A..71S, SuGOHI III)
f = Chan et al. (2020A&A...636A..87C 2020A&A...636A..87C, SuGOHI IV)
g = Jaelani et al. (2020MNRAS.495.1291J 2020MNRAS.495.1291J, SuGOHI V)
h = Jaelani et al. (2020MNRAS.494.3156J 2020MNRAS.494.3156J)
i = Sonnenfeld et al. (2020, SuGOHI VI, this paper)
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Acknowledgements:
Alessandro Sonnenfeld, sonnenfeld(at)strw.leidenuniv.nl
References:
Sonnenfeld et al., Paper I 2018PASJ...70S..29S 2018PASJ...70S..29S
Wong et al., Paper II 2018ApJ...867..107W 2018ApJ...867..107W
Sonnenfeld et al., Paper III 2019A&A...630A..71S 2019A&A...630A..71S
Chan et al., Paper IV 2020A&A...636A..87C 2020A&A...636A..87C
Jaelani et al., Paper V 2020MNRAS.495.1291J 2020MNRAS.495.1291J
(End) Alessandro Sonnenfeld [Leiden Obs.]. Patricia Vannier [CDS] 18-Aug-2020