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Accueil > Séminaires > Archive des séminaires d’Utinam > Archive des séminaires d’astrophysique (jusqu’en 2011) > 2009

Impact of Intergalactic dust absorption on cosmology with supernovae of type Ia

par Edith Burgey -

Jeudi 28 mai 2009

Martin Kilbinger

Institut d’Astrophysique de Paris

Résumé :

Supernovae of type Ia (SNIa) have become a key ingredient in current determinations of cosmological parameters. These objects can however be used as standard candles only after correcting their apparent brightness for a number of effects. In my talk I will present the effect of redshift-dependent dust extinction on SNIa and possible biases for cosmological inference. Intergalactic dust absorption was measured recently by Menard et al. (2009, arXiv:0902.4240) using QSO-galaxy correlations in SDSS induced by weak gravitational lensing. This dust component has so far been ignored by the SNIa community, and the current methods for dust correction cannot account for a redshift-dependent absorption. I will show that current parameter estimates from SNIa are potentially biased by up to half of the statistical uncertainties. At the end of my talk I will propose ways to limit and to correct for the impact of intergalactic dust (see Menard, Kilbinger & Scranton 2009, arXiv:0903.4199).