CASSOWARY

CASSOWARY Gravitational Lenses
 
C A S S O W A R Y
Cambridge And Sloan Survey Of Wide ARcs in the skY
The Cassowary is the second largest flightless bird on the planet. 
 
The Survey
The aim is to carry out systematic searches for wide separation (>1.5 arcsec) gravitational lens systems, looking for multiple, blue companions around massive ellipticals in the Sloan Digital Sky Survey (SDSS) object catalogue. Typically, the target systems correspond to lensing of z > 0.5 star-forming galaxies by luminous red galaxies and brightest cluster galaxies. The survey started in the summer of 2007 and the first version of the catalogue was published in June 2008.
 
The Catalogue
The current version (16th September, 2009 ) of the CASSOWARY catalogue contains 24 objects (counting binaries twice).
It is also available for download as an ASCII table. The 14 collumns are: CSWA ID, SDSS ObjID, RA (deg), Dec (deg), SDSS lens magnitudes (not corrected for Galactic extinction) u, g, r, i, z, SDSS SpecObj ID, lens redshift, redshift reference, source redshift, redshift reference. Missing values are indicated by -99.
 
Note RADec is linked to SDSS's Navigate page, ObjID to Explore page, SpecObj to object's spectrum GIF
 View according to  
CSWA 1
a.k.a. Cosmic Horseshoe
ObjId 587742572151374147
RADec 177.13811  19.50089
ugriz 23.3 20.8 19.0 18.2 17.8
No SDSS spectrum
ZL 0.4441  ZS 2.3791
CSWA 2.1
a.k.a. Cheshire Cat
ObjId 588013382200131773
RADec 159.68164  48.82160
ugriz 23.0 20.3 18.6 17.9 17.4
SpecObj 246515463746486272
ZL 0.426  ZS 0.972
CSWA 2.2
a.k.a. Cheshire Cat
ObjId 588013382200131774
RADec 159.67790  48.82230
ugriz 22.3 20.6 18.8 18.2 17.7
No SDSS spectrum
ZL 0.4322  ZS 0.972
CSWA 3
ObjId 588017605222793376
RADec 190.13452  45.15079
ugriz 21.2 20.0 18.4 17.9 17.6
No SDSS spectrum
ZL 0.2742  ZS 0.7252
CSWA 4
ObjId 588023046402670876
RADec 135.34322  18.24232
ugriz 21.5 19.7 18.0 17.3 17.0
SpecObj 642838136396709888
ZL 0.346  ZS 2.25867
CSWA 5.1
ObjId 588848901528223970
RADec 191.21400  1.11193
ugriz 22.3 20.6 19.1 18.4 18.0
No SDSS spectrum
ZL ?  ZS ?
CSWA 5.2
ObjId 588848901528223971
RADec 191.21257  1.11222
ugriz 22.3 20.4 18.4 17.9 17.7
SpecObj 82132249671106560
ZL 0.388  ZS ?		CSWA 6
ObjId 588013382206357664
RADec 181.50873  51.70820
ugriz 22.7 20.0 18.4 17.7 17.3
SpecObj 248767590678134784
ZL 0.433  ZS 2.008
CSWA 7
ObjId 588295841784725744
RADec 174.41690  49.60988
ugriz 24.5 21.2 19.4 18.6 18.2
SpecObj 272412374034546688
ZL 0.448  ZS 1.4116
CSWA 8
a.k.a. SDSS J120923.7+264047
ObjId 587741600957333763
RADec 182.34869  26.67960
ugriz 24.9 20.8 19.0 17.9 17.4
SpecObj 627638892169789440
ZL 0.558  ZS 1.0185
CSWA 9
ObjId 587742902862086260
RADec 186.82809  17.43108
ugriz 22.7 19.9 17.9 17.3 16.8
No SDSS spectrum
ZL ?  ZS ?		CSWA 10
ObjId 587730773880078847
RADec 339.63048  13.33218
ugriz 21.3 19.8 17.9 17.2 16.7
SpecObj 208235580448833536
ZL 0.413  ZS ?
CSWA 11
ObjId 587744873710682762
RADec 120.05442  8.20233
ugriz 22.4 19.3 17.7 17.0 16.7
No SDSS spectrum
ZL ?  ZS ?		CSWA 12
a.k.a. MACS J1133.2+5008
ObjId 587732484357095512
RADec 173.30488  50.14447
ugriz 20.7 19.4 18.1 17.5 17.0
No SDSS spectrum
ZL 0.3944  ZS 1.5444
CSWA 13
ObjId 587731870173298881
RADec 189.40086  55.56191
ugriz 23.4 20.7 18.8 18.1 17.5
SpecObj 287330913719681024
ZL 0.410  ZS ?		CSWA 14
ObjId 587736980648362708
RADec 260.90071  34.19945
ugriz 22.6 20.1 18.4 17.6 17.3
No SDSS spectrum
ZL ?  ZS ?
CSWA 15.1
ObjId 587742014344265970
RADec 152.24908  19.62153
ugriz 21.3 19.0 17.4 16.7 16.5
SpecObj 667889578840948736
ZL 0.306  ZS ?		CSWA 15.2
ObjId 587742014344265969
RADec 152.24697  19.62094
ugriz 21.8 19.3 17.6 16.8 16.4
SpecObj 668171053188513792
ZL 0.465  ZS ?
CSWA 16.1
ObjId 587731868557115670
RADec 167.76535  53.14858
ugriz 22.1 20.2 18.7 18.0 17.6
No SDSS spectrum
ZL ?  ZS ?		CSWA 16.2
ObjId 587731868557115671
RADec 167.76380  53.14773
ugriz 24.5 20.7 19.0 18.2 17.8
No SDSS spectrum
ZL ?  ZS ?
CSWA 17
ObjId 587741709956546742
RADec 174.53732  27.90853
ugriz 21.6 20.4 18.7 18.1 17.8
No SDSS spectrum
ZL ?  ZS ?		CSWA 18
ObjId 587742191511273514
RADec 173.52810  25.55977
ugriz 17.3 15.3 14.4 14.0 13.7
No SDSS spectrum
ZL ?  ZS ?
CSWA 19
ObjId 587741421640024462
RADec 135.01103  22.56803
ugriz 24.1 21.1 19.1 18.2 17.9
SpecObj 643119522567421952
ZL 0.489  ZS ?		CSWA 20
ObjId 587742611340001632
RADec 220.45482  14.68905
ugriz 24.6 25.1 22.7 20.7 20.2
No SDSS spectrum
ZL 0.7419  ZS 1.4339
The Follow-up
We have obtained follow-up for some of these systems on a number of telescopes including
However, most of the candidates still require spectroscopic confirmation and/or deeper imaging. We welcome the community worldwide to join on the effort of studying these spectacular systems.
 

References

  1. SDSS public data release
  2. "The Cosmic Horseshoe: Discovery of an Einstein Ring around a Giant Luminous Red Galaxy", Belokurov et al. 2007
  3. "Models of the Cosmic Horseshoe Gravitational Lens", Dye et al. 2008
  4. "Two New Large Separation Gravitational Lenses from SDSS", Belokurov et al. 2008
  5. "A Systematic Search for Gravitationally Lensed Arcs in the Hubble Space Telescope WFPC2 Archive", Sand et al. 2005
  6. "SDSS J120923.7+264047: A new massive galaxy cluster with a bright giant arc", Ofek et al. 2008
  7. "The Sloan Bright Arcs Survey: Six Strongly Lensed Galaxies at z = 0.4-1.4", Kubo et al. 2009
  8. "Rest-Frame Optical Spectra of Three Strongly Lensed Galaxies at z~2", Hainline et al. 2009
  9. "Discovery of A Very Bright, Strongly-Lensed z=2 Galaxy in the SDSS DR5", Lin et al. 2008
  10. "CASSOWARY 20: a Wide Separation Einstein Cross Identified with the X-shooter Spectrograph", Pettini et al. 2009
 

The People
@IoA: Vasily Belokurov, Wyn Evans, Paul Hewett, Lindsay King, Richard McMahon, Lukasz Wyrzykowski, Max Pettini, Martin Smith, Mike Irwin
@SAO: Alexei Moiseev
@MPIA: Sergey Koposov
@Cardiff: Simon Dye
@Imperial: Stephen Warren
 

Credits
The catalogue is distributed freely. The candidate selection procedure is described in our latest paper.

As most of the information presented here is based on the SDSS data, one might want to consider using standard SDSS acknowledgement as well.