Weak lensing mass-selected cluster catalogues Richard Massey (CalTech) with Justin Albert (CalTech), Joel Berg é (Saclay), Richard Ellis (CalTech), Alexis Finogeunov (Garching), Luigi Guzzo (INAF), Catherine Heymans (UBC), Jean-Paul Kneib (Marseille), Alexie Leauthaud (Marseille), Alexandre Refregier (Saclay), Jason Rhodes (JPL), Nick Scoville (CalTech), James Taylor (CalTech), Ludovic Van Waerbeke (UBC) and the COSMOS team Weak lensing mass maps from the HST COSMOS survey

COSMOS: “Cosmic Evolution Survey” Largest ever HST survey 587 contiguous ACS fields 2 square degrees V SDSS at z=1 Depth I F814 <26.6 (at 5  ) 2 million galaxies ~80 resolved galaxies/arcmin 2 Public data!

Multiwavelength follow-up

COSMOS team members Nick Scoville (PI) Roberto Abraham Masaru Ajiki Justin Alpert Herve Aussel Josh Barnes Andrew Blain Daniela Calzetti Peter Capak John Carlstrom Chris Carilli Andrea Cimatti Andrea Comastri Marcella Corollo Emannuel Daddi Richard Ellis Martin Elvis Amr El Zant Shawn Ewald Mike Fall Alexis Finoguenov AlbertoFranceschini Mauro Giavalisco Richard Griffiths Gigi Guzzo Gunther Hasinger Chris Impey Jean-Paul Kneib Karel Nel Jeyhan Kartaltepe Jin Koda Anton Koekemoer Lisa Kewley Alexie Leauthaud Olivier LeFevre Ingo Lehmann Simon Lilly Thorsten Lisker Charles Liu Richard Massey Henry McCracken Yannick Mellier Satoshi Miyazaki Bahram Mobasher Takashi Murayama Colin Norman Alexandre Refregier Alvio Renzini Jason Rhodes Mike Rich Dimitra Rigopoulou Dave Sanders Shunji Sasaki Dave Schminovich Eva Schinnerer Marco Scodeggio Kartik Sheth Patrick Shopbell Jason Surace Yoshi Taniguchi James Taylor Dave Thompson Neil Tyson Meg Urry Ludovic Van Waerbeke Paolo Vettolani Simon White Lin Yan

Issues from space - to bear in mind for DUNE, SNAP,… ACS pixels are slightly undersampled. PSF is not stable even from space - HST “breathes”. Charge transfer (in)efficiency in CCDs that have been degraded by cosmic rays. 8 band photo-zs are not yet totally reliable. 10 additional bands to be observed during 2006.

Strong Gravitational Lensing A gravitational field distorts all of space-time like a rubber sheet. Even light rays bend around the massive cores of galaxy clusters. The image of a background galaxy can be strongly lensed into multiple sources (corresponding to multiple paths around the lens) and distorted into arcs. Gravitational lensing is geometric. It occurs regardless of the nature and state of the foreground mass, and can thus be a bias-free probe of dark matter!

Light actually follows the distorted path (exaggerated) through intervening large-scale structure. Adjacent background galaxies are coherently distorted into an ellipse. Like glass lenses, gravitational lenses are most effective when placed half way between the source and the observer. z observer =0 z galaxy ≈1 z lens ≈0.3–0.5 The measurement of weak gravitational lensing relies on the fact that averaging the shapes of ~100 distant galaxies produces a circle. Weak Gravitational Lensing

Weak gravitational lensing: patterns in a shear field Clusters are patterns in a shear field:

The usual cosmic shear analysis: shear-shear correlation functions

(Photometric) redshift tomography 0.4<z< <z< <z<1.5 z>1.5

PRELIMINARY! Cosmological parameter constraints Courtesy Joel Berg é 88 ΩmΩm w w

Mass map of COSMOS survey Using wavelet reconstruction method of Starck et al. (2006) See poster by Sandrine Pires Sorry - this image is not yet publicly available

Residual systematics (“B modes”) Sorry - this image is not yet publicly available

Lensing sensitivity with redshift Number of resolved galaxies z

Mass vs light Sorry - this image is not yet publicly available

Mass vs x-rays Gunther Hasinger, Alexis Finoguenov & Nico Cappelluti Sorry - this image is not yet publicly available

Mass vs x-rays Courtesy Alexis Finoguenov

Zoom to one cluster at z=0.73 Lensing X-ray Guzzo et al. (2006)

Lensing sensitivity function (split)

Lensing sensitivity function (tomography) Number of resolved galaxies z

Tomography (3D maps) Sorry - this image is not yet publicly available

Tomography (3D maps) Sorry - this image is not yet publicly available

Tomography (3D maps) Sorry - this image is not yet publicly available

PRELIMINARY! Completely 3D maps… Courtesy David Bacon This was displayed via IDL… Even powerpoint isn’t that good!

Conclusions COSMOS is the largest ever HST survey, sampling a complete range of large-scale structure and environments. Public data Tomographic weak lensing analysis constrains Ω m,  8 and w. Reconstructed mass maps provide a direct view of the filamentary dark matter distribution with unprecedented resolution. Maps can be made fully 3D. Optimally-tuned lensing analysis around identified structures links into astrophysics (MD relation, x-ray MT, cluster formation…)