Observational Studies of High Redshift Quasars

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ABSTRACT AST 94-15574 SCHMIDT, Maarten This grant will continue systematic surveys of quasars of very large redshifts, in order to explore their properties in the first few billion years after the Big Bang. Because quasars are highly luminous, they can be observed to larger distances (and so greater ages, when the Universe was much younger) than any other astronomical object. Since quasars optically look just like stars, the main problem in finding them is how to discriminate them from stars. The survey technique in this study involves video recording of low dispersion spectra, which in the case of large redshift (i.e. large distance) quasars will exhibit the strong emission line Lyman-alpha. The survey is conducted like a census, aiming for completeness to well defined limits. A sharp downturn in the number of quasars found in previous work beyond a redshift of 3 indicates that the initial period of birth of quasars, and probably that of galaxies as well, is being observed. ***