Gravitational lensing: surveys and studies with new instruments

Science: structure and evolution of galaxies What is the overall profile slope, and how did it get that way? How much blobby CDM stuff is there here? What is the central profile, and why is what goes on in the middle so important for the structure of the rest of the galaxy? Image 3”=~20kpc Mostly DM out here mostly baryons in here

Science: structure and evolution of galaxies What is the overall profile slope, and how did it get that way? How much blobby CDM stuff is there here? What is the central profile, and why is what goes on in the middle so important for the structure of the rest of the galaxy? Image 3”=~20kpc SLACS (Bolton+, Koopmans+) - isothermal conspiracy – hard to simulate over wide z range Flux anomalies in CLASS radio quads (Mao&Schneider, Dalal&Kochanek – picture confused, some seen, not understood) One central image seen in galaxy-only lens (Winn+)

Science: structure and evolution of galaxies What is the overall profile slope, and how did it get that way? How much blobby CDM stuff is there here? What is the central profile, and why is what goes on in the middle so important for the structure of the rest of the galaxy? Image 3”=~20kpc SLACS (Bolton+, Koopmans+) - isothermal conspiracy – hard to simulate over wide z range Flux anomalies in CLASS radio quads (Mao&Schneider, Dalal&Kochanek – picture confused, some seen, not understood) One central image seen in galaxy-only lens (Winn+) Need more statistics (>80) particularly at high redshift Need more statistics (>7) especially lenses with long- fluxes Need more statistics (>1)

Science: structure and evolution of galaxies What is the overall profile slope, and how did it get that way? How much blobby CDM stuff is there here? What is the central profile, and why is what goes on in the middle so important for the structure of the rest of the galaxy? Image 3”=~20kpc SLACS (Bolton+, Koopmans+) - isothermal conspiracy – hard to simulate over wide z range Flux anomalies in CLASS radio quads (Mao&Schneider, Dalal&Kochanek – picture confused, some seen, not understood) One central image seen in galaxy-only lens (Winn+) Need more statistics (>80) particularly at high redshift Need more statistics (>7) especially lenses with long- fluxes Need more statistics (>1) More lenses of all types (LSST, Pan-STARRS,JDEM,SKA.....) Substructure-friendly lenses e-MERLIN, LSST,SKA.... e-MERLIN on existing lenses

Science: structure and evolution of galaxies What is the overall profile slope, and how did it get that way? How much blobby CDM stuff is there here? What is the central profile, and why is what goes on in the middle so important for the structure of the rest of the galaxy? Image 3”=~20kpc SLACS (Bolton+, Koopmans+) - isothermal conspiracy – hard to simulate over wide z range Flux anomalies in CLASS radio quads (Mao&Schneider, Dalal&Kochanek – picture confused, some seen, not understood) One central image seen in galaxy-only lens (Winn+) Need more statistics (>80) particularly at high redshift Need more statistics (>7) especially lenses with long- fluxes Need more statistics (>1) More lenses of all types (LSST, Pan-STARRS,JDEM,SKA.....) Substructure-friendly lenses e-MERLIN, LSST,SKA.... e-MERLIN on existing lenses This talk, section 1 Section 2 Also: given cosmological model, z/separation statistics give parameters for galaxy evolution models

Discovery of new lenses: short-term: efficient use of existing surveys (SL2S, COSMOS,UKIDSS/MUSCLES....) long-term: big new instruments (e.g. LSST, JDEM, SKA...) Faure et al.2008 Jackson 2008 Cabanac et al. 2008

SQLS (SDSS quasar lens survey) Major optical quasar survey to date: SQLS (Sloan quasars) Inada et al Inada et al Inada et al ~25 lenses

CLASS survey separation histogram SDSS seeing UKIDSS seeing

Muscles survey selection Sloan quasars (to DR5) UKIDSS to date -> inspect visually for extensions (not necessarily the same colour) 150 candidates Detects all (6) known quasar lenses!

MUSCLES-1 and 2 Combination SDSS+UKIDSS (Jackson, Ofek & Oguri 2008) Jackson, Ofek & Oguri 2009

MUSCLES-1 and 2 Combination SDSS+UKIDSS (Jackson, Ofek & Oguri 2008) Jackson, Ofek & Oguri 2009

Studies of the central <100pc: core images PMN : Winn, Rusin & Kochanek 2003, 2004

Attempts to detect in galaxy-only lenses have been unsuccessful due to limited sensitivity.... Recent HSA (VLA+GB+VLBA+Arecibo) observations of CLASS B (Zhang et al. 2007)

Other scales: 2. The central 10pc Recent HSA (VLA+GB+VLBA+Arecibo) observations of CLASS B (Zhang et al. 2007) (Lack of) central image constrains the steepness of the central part of the potential. Steeper central profile or large BH gives weaker central image Interesting constraints await e-Merlin

existing sensitivity levels e-Merlin Currently: 1 radio lens/30; for standard BH and cusp parameters, should detect many more! -> determine these parameters

Summary need larger samples of both - quasar-galaxy lenses - galaxy-galaxy lenses to contribute to studies of - central potentials – BHs, cusps... - substructure via flux anomalies or direct mapping - mass profiles – how do they get like that? - statistics – parametrised galaxy evolution Short term: use existing surveys to maximum (UKIDSS, COSMOS,SDSS,SL2S) -> dozens of lenses Medium term: studies of existing lenses (e-MERLIN,EVLA...), new surveys (PanSTARRS) -> hundreds of lenses Long term: LSST, JDEM, SKA.... -> thousands of lenses, ultimate statistics, galaxy evolution...