ИСТИНА

Cosmological parameters are estimated from the "luminosity distance-redshift" relation of SNe Ia using the Hubble diagram. Currently a lot of attention is paid to standardization of SNe. However, it is known that peculiar velocities of SNe also introduce an additional uncertainty on the Hubble diagram and therefore have an impact on cosmological parameters. To minimize the influence of poorly constrained peculiar velocities, a standard value of 300 km s-1 peculiar velocity dispersion is usually added to the redshift uncertainty. It has nonetheless been observed that velocity dispersion can exceed 1000 km s-1 in galaxy clusters. To take this effect into account we studied 145 Nearby Supernova Factory supernovae that exploded in the galaxy clusters. We used the galaxy cluster redshift instead the host galaxy redshift to construct the Hubble diagram. The applied technique allowed to improve the distance measurements for low redshifts and to decrease the scatter on the Hubble diagram. We also found that supernovae in clusters are more standard and therefore more suitable for the cosmology. The correction for the peculiar velocities of the galaxies inside the clusters is important for distance measurements and has to be taken into account in future cosmological surveys (such as LSST).