Discovery of Cluster-ScaleDiscovery of Cluster-ScaleLensed Quasars using the Lensed Quasars using the

Subaru TelescopeSubaru Telescope

Naohisa InadaNaohisa Inada （（ RIKENRIKEN ））M.Oguri, T.Broadhurst, E.Falco et al.

Subaru Users’ Meeting29 － 31 Jan. 2008 @NAOJ

We are carrying out the SSloan Digital Sky Survey QQuasar LLens SSearch （ SQLSSQLS ） . The main purposes of the SQLS are 1 ） constructing a large statistical sample of lensed quasars and 2 ） searching quasars lensed by searching quasars lensed by clusters of galaxiesclusters of galaxies, i.e., a new population of lensed quasars. So far we have succeeded in discovering two cluster-scale lensed quasars, SDSS J1004+4112SDSS J1004+4112 and SDSS J1029+2623SDSS J1029+2623. We used the Subaru TelescopeSubaru Telescopefor the discoveries and further follow-up observations discoveries and further follow-up observations of both of themof both of them.

# OUTLINE #

Introduction

Overview of the SQLS :Overview of the SQLS : Gravitationally lensed quasar survey using the SDSS data. ~50 new lensed quasars~50 new lensed quasars are expected to be discovered from the ~100,000 SDSS quasars.

Main Purposes :Main Purposes :1 ） Constructing a largest statistical samplelargest statistical sample of lensed quasars to probe dark energy.２） Discovering cluster-scale lensed quasarscluster-scale lensed quasars to probe dark matter in galaxy clusters.

Current Status :Current Status :We have succeeded in discovering 28 lensed quasars28 lensed quasarsso far, including 2 cluster-scale lensed quasarsincluding 2 cluster-scale lensed quasars. We have completed the first statistical sample from DR3.

Discovery of SDSS J1004+4112

SDSS J1004+4112SDSS J1004+4112 : The firstfirst （ 1/2 ） cluster-scale lensed quasar. = 14.6", zsource = 1.734, zlens = 0.680

Subaru Suprime-CamSubaru Suprime-Cam Keck LRIS

existence of the lensinggalaxy cluster

originate a single source quasar

gri-band

A

B

C

D

Discovery of SDSS J1029+2623

SDSS J1029+2623SDSS J1029+2623 : The secondsecond （ 2/2 ） cluster-scale lensed quasar. = 22.3", zsource = 2.197, zlens = 0.600

Subaru FOCASSubaru FOCAS VLAexistence of lensing galaxy cluster

originate a single source quasar

A

B

Central lensed image of SDSS J1004+4112

A

B

C

D

E

CE

spectroscopically confirmedcentral odd lensed image!!（ NFW +ρ < 2.0 ）

HST ACS

FOCASFOCAS

Arcs in the SDSS J1029+2623 field

V between G1 and G2is more than 2000 km/s

FOCASFOCAS

FOCASFOCASMany arcs are found in the J1029 field

We are going to propose service obsfor deeper images.

ongoing mergerongoing merger of two clusters!?

Summary

# References #

J1004 discovery : Inada et al. 2003, Nature, 426, 810 ; Oguri et al. 2004, ApJ, 605, 78J1029 discovery : Inada et al. 2006, ApJ, L97J1004 central image : Inada et al. 2005, PASJ, 57, L7 ; Inada et al. in preparationJ1029 follow-up : Oguri et al. ApJL submitted

• We discovered two cluster-scale lensed quasars, SDSS J1004+4112 and SDSS J1029+2623 using the Subaru Telescope.

• Further follow-up observations with Subaru : We spectroscopically confirmed the central lensed image of J1004, and we may find J1029 to be more interesting （ important ） than J1004.