J/ApJ/749/38 CFHTLS-SL2S-ARCS strong lens candidates (More+, 2012)
The CFHTLS-Strong Lensing Legacy Survey (SL2S): investigating the group-scale
lenses with the SARCS sample.
More A., Cabanac R., More S., Alard C., Limousin M., Kneib J.-P.,
Gavazzi R., Motta V.
<Astrophys. J., 749, 38 (2012)>
=2012ApJ...749...38M 2012ApJ...749...38M
ADC_Keywords: Gravitational lensing ; Photometry, VRI ; Redshifts ; Surveys
Keywords: dark matter - gravitational lensing: strong - methods: data analysis -
surveys
Abstract:
We present the Strong Lensing Legacy Survey-ARCS (SARCS) sample
compiled from the final T0006 data release of the Canada-France-Hawaii
Telescope Legacy Survey (CFHTLS) covering a total non-overlapping area
of 159 deg2. We adopt a semi-automatic method to find gravitational
arcs in the survey that makes use of an arc-finding algorithm. The
candidate list is pruned by visual inspection and ranking to form the
final SARCS sample. This list also includes some serendipitously
discovered lens candidates which the automated algorithm did not
detect. The SARCS sample consists of 127 lens candidates which span
arc radii ∼2"-18" within the unmasked area of ∼150 deg2. Within the
sample, 54 systems are promising lenses among which, we find 12 giant
arcs (length-to-width ratio ≥ 8). We also find two radial arc
candidates in SL2SJ141447+544704. From our sample, we detect a
systematic alignment of the giant arcs with the major axis of the
baryonic component of the putative lens in concordance with previous
studies. This alignment is also observed for all arcs in the sample
and does not vary significantly with increasing arc radius. The mean
values of the photometric redshift distributions of lenses
corresponding to the giant arcs and all arcs sample are at z∼0.6.
Description:
We present the Strong Lensing Legacy Survey-ARCS (SARCS) sample from
the completed CFHTLS-WIDE and CFHTLS-DEEP covering a combined unmasked
area of ∼150deg2 in the sky. The lens sample is compiled through a
semi-automatic technique consisting of using the ARCFINDER algorithm,
followed by visual inspection and ranking of the candidates. We
briefly described how ARCFINDER works (Alard 2006astro.ph..6757A 2006astro.ph..6757A) and
the modifications implemented in the newer version of the algorithm.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 82 127 Characteristics of lens candidates from the SARCS
(Strong Lensing Legacy Survey-ARCS) sample
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See also:
II/317 : The CFHTLS Survey (T0007 release) (Hudelot+ 2012)
VIII/72 : CLASS survey of radio sources (Myers+, 2003)
J/ApJ/705/1099 : The Sloan Lens ACS (SLACS) Survey. IX. (Auger+, 2009)
J/ApJ/690/670 : The Sloan lens ACS Survey. VIII. (Treu+, 2009)
J/ApJS/176/19 : COSMOS: strong lens systems (Faure+, 2008)
J/ApJ/682/964 : Sloan lens ACS survey. V. (Bolton+, 2008)
J/ApJ/668/643 : Multiply imaged gravitational lens systems (Limousin+, 2007)
J/ApJ/600/L155 : Gravitational lens in GOODS ACS fields (Fassnacht+, 2004)
http://kicp.uchicago.edu/~anupreeta/sarcs_sample : Images for SL2S-Arcs sample
http://terapix.iap.fr/rubrique.php?id_rubrique=259 : CFHTLS T0006 release page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- ID Lens candidate identification (SANNN)
<[MCM2012] SANNN lens> in Simbad
7- 8 A2 --- n_ID [ CGRmz] Individual notes on lens candidate (1)
10- 11 I2 h RAh Hour of right ascension (J2000)
13- 14 I2 min RAm Minute of right ascension (J2000)
16- 20 F5.2 s RAs Second of right ascension (J2000)
22 A1 --- DE- Declination sign (J2000)
23- 24 I2 deg DEd Degree of declination (J2000)
26- 27 I2 arcmin DEm Arcminute of declination (J2000)
29- 33 F5.2 arcsec DEs Arcsecond of declination (J2000)
35- 39 F5.2 mag gmag [17.2/25.5] CFHT g-band AB magnitude
41- 45 F5.2 mag rmag [16.3/24.6] CFHT r-band AB magnitude
47- 51 F5.2 mag imag [15.9/23.2] CFHT i-band AB magnitude
53- 56 F4.2 --- zph [0.05/1.3] Photometric redshift of the lens
58- 61 F4.2 --- e_zph [0.01/1.1] zph uncertainty
63 A1 --- n_zph [z] zph from literature (1)
65- 68 F4.1 arcsec Rad [0/18.4]?=0 Arc radius in arcsec (2)
70- 73 F4.1 --- RA [0/82]?=0 Arc radius RA in units of h-1.kpc (2)
75- 77 F3.1 --- Rank [2/4] Individually assigned rank (1: least
likely to 4: almost certain lens system)
79 A1 --- D [AV] Detection type (3)
81- 82 A2 --- Fld CFHT-LS Field name in which the candidate is
located (D1-D4 or W1-W4) (4)
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Note (1): Flag as follows:
m = this galaxy falls within the masked region as per the catalog from which
the magnitudes and the redshift are extracted.
z = the magnitudes and/or redshift are not from the Coupon et al.
2009A&A...500..981C 2009A&A...500..981C catalog instead are measured by the author using
sextractor and/or zebra (Feldmann et al. 2006MNRAS.372..565F 2006MNRAS.372..565F), respectively
C = this lens is identified in both D2 and COSMOS fields. Note that other
lenses within D2 have not been reported in the COSMOS lens sample (Faure
et al. 2008, Cat. J/ApJS/176/19).
R = this lens is also found in RCS (see Gladders et al. 2003ApJ...593...48G 2003ApJ...593...48G).
G = this lens is also a part of the SL2S-RINGS sample.
Note (2): We define the SARCS sample such that lens systems with arc radius
(RA)≳2" belong to the sample. The radius of the arc is defined as
the distance of the lensed image from the putative lens galaxy which
is roughly the Einstein radius. Typically, lensing halos with Einstein
radius larger than 2" are very massive lenses with significant
contribution from the environment of the primary lensing galaxy. For
the calculation of arc radii in physical units, we use flat cosmology
with following parameters
(Ωm,ΩΛ,H0)=(0.3,0.7,100km/s/Mpc).
Note (3): The type indicating whether the candidates are primarily detected
via the ARCFINDER. The symbol "A" stands for detection by ARCFINDER
and "V" implies that a candidate is found serendipitously.
Note (4): The CFHTLS-WIDE consists of four fields, W1, W2, W3, and W4.
Field W1 has the largest sky coverage of 63.65deg2. Fields W2 and W4
have similar sky coverages of 20.32deg2 and 20.02deg2,
respectively (http://terapix.iap.fr/cplt/table_syn_T0006.html). Field
W3 has a sky coverage of 42.87deg2 and is more than twice as large
as W2 and W4. The CFHTLS-DEEP encompassing a combined area of 4deg2.
DEEP also consists of four fields, D1 (located within the W1 field),
D2, D3, and D4. Each of the deep fields covers an area of 1deg2. See
section 2.1 for further details.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 12-Nov-2013