Weak Lensing of Type Ia Supernovae from the Dark Energy Survey

E. Macaulay , D. Bacon , R.C. Nichol , T.M. Davis , J. Elvin-Poole , D. Brout , D. Carollo , K. Glazebrook , S.R. Hinton , G.F. Lewis , C. Lidman , A. Möller (1) , M. Sako , D. Scolnic , M. Smith , N.E. Sommer , B.E. Tucker , T.M.C. Abbott , M. Aguena , J. Annis , S. Avila , E. Bertin (2) , S. Bhargava , D. Brooks , D.L. Burke , A. Carnero Rosell , M. Carrasco Kind , J. Carretero , F.J. Castander , M. Costanzi , L.N. da Costa , S. Desai , H.T. Diehl , P. Doel , B. Flaugher , R.J. Foley , J. García-Bellido , E. Gaztanaga , D.W. Gerdes , D. Gruen , R.A. Gruendl , J. Gschwend , G. Gutierrez , D.L. Hollowood , K. Honscheid , D. Huterer , D.J. James , K. Kuehn , N. Kuropatkin , O. Lahav , M. Lima , M.A.G. Maia , J.L. Marshall , P. Melchior , F. Menanteau , R. Miquel , A. Palmese , A.A. Plazas , A.K. Romer , A. Roodman , E. Sanchez , V. Scarpine , M. Schubnell , S. Serrano , I. Sevilla-Noarbe , M. Soares-Santos , E. Suchyta , M.E.C. Swanson , G. Tarle , T.N. Varga , A.R. Walker , J. Weller

1 LPC - Laboratoire de Physique de Clermont
2 IAP - Institut d'Astrophysique de Paris

We consider the effects of weak gravitational lensing on observations of 196 spectroscopically confirmed Type Ia Supernovae (SNe Ia) from years 1 to 3 of the Dark Energy Survey (DES). We simultaneously measure both the angular correlation function and the non-Gaussian skewness caused by weak lensing. This approach has the advantage of being insensitive to the intrinsic dispersion of SNe Ia magnitudes. We model the amplitude of both effects as a function of σ_8, and find σ_8 =1.2|$^{+0.9}_{-0.8}$|⁠. We also apply our method to a subsample of 488 SNe from the Joint Light-curve Analysis (JLA; chosen to match the redshift range we use for this work), and find σ_8 =0.8|$^{+1.1}_{-0.7}$|⁠. The comparable uncertainty in σ_8 between DES–SN and the larger number of SNe from JLA highlights the benefits of homogeneity of the DES–SN sample, and improvements in the calibration and data analysis.

Mots clés: cosmological parameters; cosmology: observations; large-scale structure of the universe

Domaines: Astrophysique [astro-ph]

E. Macaulay, D. Bacon, R.C. Nichol, T.M. Davis, J. Elvin-Poole, et al.. Weak Lensing of Type Ia Supernovae from the Dark Energy Survey. Monthly Notices of the Royal Astronomical Society, 2020, 496 (3), pp.4051-4059. ⟨10.1093/mnras/staa1852⟩. ⟨hal-02911936⟩