October 29, 1998 CfA Colloquium


Title: The First Stars and Quasars

Speaker: Abraham Loeb

Abstract: The first generation of stars and quasars resulted directly from the growth of linear density fluctuations in the early Universe. These sources had a substantial impact on the thermal and chemical state of the rest of the Universe, as they re-ionized most of the intergalactic gas and enriched it with metals. Galaxies are currently being discovered at redshifts between 5-6, but their spectra do not show yet the Gunn-Peterson absorption trough due to a neutral intergalactic medium. The planned Next Generation Space Telescope (the successor to the Hubble Space Telescope) will be able to detect star clusters and mini-quasars at redshifts greater than 10 and image the epoch of re-ionization.

Reference for students: The First Stars and Quasars