CFHTLS weak-lensing constraints on the neutrino masses*
Argelander-Institut für Astronomie, Auf dem Hügel 71, 53121 Bonn, Germany e-mail: email@example.com
2 Institut d'Astrophysique de Paris, CNRS UMR 7095 & UPMC, 98 bis bd Arago, 75014 Paris, France
3 Laboratoire d'Astrophysique de Marseille, 38 rue Joliot-Curie, 13388 Marseille, France
4 Université de Provence – Aix - Marseille I , Marseille, France
5 INAF – Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
6 Shanghai Key Lab for Astrophysics, Shanghai Normal University, 200234 Shanghai, PR China
Accepted: 7 February 2009
Context. Oscillation experiments yield strong evidence that at least some neutrinos are massive. As a hot dark-matter component, massive neutrinos should modify the expansion history of the Universe as well as the evolution of cosmological perturbations, in a different way from cold dark matter or dark energy.
Aims. We use the latest release of CFHTLS cosmic-shear data to constrain the sum of the masses of neutrinos, assuming three degenerate mass states. We also consider a joint analysis including other cosmological observables, notably CMB anisotropies, baryonic acoustic oscillations, and distance modulus from type Ia supernovae.
Methods. Combining CAMB with a lensing code, we compute the aperture mass variance using a suitable recipe to deal with matter perturbations in the non-linear regime. The statistical analysis is performed by sampling an 8-dimensional likelihood on a regular grid as well as using the importance sampling technique.
Results. We obtain the first constraint on neutrino masses based on cosmic-shear data, and combine CFHTLS with WMAP, SDSS, 2dFGRS, Gold-set, and SNLS data. The joint analysis yields 0.03 eV eV at the 95% confidence level. The preference for massive neutrinos vanishes when systematics are included.
Key words: cosmology: cosmological parameters / neutrinos / cosmology: large-scale structure of Universe / gravitational lensing
Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS.
© ESO, 2009