Measuring the expansion of the Universe with quasars
ll giorno giovedì 10 Dicembre 2020 alle ore 14.00, sulla piattaforma Microsoft Teams (apertura Team 13:50),
il Prof. Guido Risaliti, del Dipartimento di Fisica e Astronomia dell'Università di Firenze, terrà un Colloquium intitolato:
"Measuring the expansion of the Universe with quasars"
ABSTRACT
Quasars are the most luminous persistent sources in the Universe, and more than half million of them have been observed and spectroscopically confirmed up to redshift z>7, corresponding to an age of the Universe of a few hundred million years. For these reasons, they would be optimal tracers of the expansion of the Universe through a distance-age relation. In order to achieve this goal, we need to be able to estimate quasar distances from their luminosities (i.e. to use them as "standard candles"). I present the work of my group on this subject, showing that it is possible to determine quasar distances from their multi-wavelength spectral properties. Once these results are applied to the test of cosmological models, we find a tension at >4 sigma with the standard "concordance" model.
Per partecipare
Il Team è reperibile con il codice 2hvyhfx.
Per qualsiasi dubbio o richiesta contattare gli organizzatori micol.benetti@unina.it e marco.coraggio@unina.it
Data:
10/12/2020