Probing the end of the reionization epoch with the most distant galaxies
Astronomy and astrophysics
Friday 25 April 2014
to 11:30 at
Laura Pentericci (INAF-Rome)
The epoch of re-ionization is a fascinating time in the history of the Universe and many uncertainties still plague our understanding of when and how it occurred.
Lyman alpha emitting galaxies at high redshift offer a powerful probe to study both reionization and the process of galaxy formation. In particular Lyman alpha emission is an efficient tool for identifying young galaxies and for measuring how much neutral hydrogen is present in the environment of the galaxies, thus providing a reionization test that is independent of the Gunn-Peterson trough observations in quasar spectra.
The last few years have seen a number of discoveries that offered the first glimpse of the Universe at z =7, using both space and ground-based telescopes. I will review the most recent observational results on high redshift galaxies, namely Ly alpha emitters and Lyman break galaxies. In particular I will review the current constrains that we can place on
the reionization epoch using the first statistical samples of spectroscopically confirmed z=7 Lyman break galaxies, the evolution of the luminosity functions and of the clustering strength of Ly alpha emitters.
I will finally present very recent ALMA observations which reveal, for the first time the nature and physical properties of these primeval galaxies that were probably responsible for the reionization.