The first ultraviolet quasar stacked spectrum at z~2.4 from WFC3

tenuto da Elisabeta Lusso (INAF, Osservatorio Astrofisico di Arcetri)

  • Data: 19 febbraio 2015 dalle 14:00 alle 15:30

  • Luogo: Aula seminari, piano -1, via Ranzani 1

Contatto di riferimento:


Over the last decades, considerable effort has been devoted in characterizing the shape of the quasar ionizing continuum in the ultraviolet. The ionizing continuum from active galactic nuclei is, in fact, of fundamental importance for interpreting their broad emission lines and for understanding their impact on the surrounding gas. Furthermore, it provides hints on how the matter is accreted onto the super massive black hole. I will present the first ultraviolet composite of quasars at high redshift (~2.4) with proper correction for the intervening Ly_alpha forest and continuum absorption. I will compare this composite quasar spectrum with previous results at lower redshift and discuss its implication in the context of photoionization disk models.