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Quasars & Galaxies |
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Quasars & Galaxies |
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Quasars are among the most luminous objects in the universe which can be observed at great distances and large look-back times. Assuming that the gas of quasars is related to the interstellar medium of the host galaxy it can be used to trace the chemical abundance evolution. The prominent emission line spectrum of quasars provides several diagnostic line ratios to measure the gas chemical composition (Hamann et al.2002). Investigations of the emission line spectra have shown that quasars at redshift z > 3 have metallicities of at least solar or higher (Hamann & Ferland 1993; Ferland et al.1996; Korista et al.1996; Hamann & Ferland 1999; Dietrich & Wilhelm-Erkens 2000; Dietrich et al.2003a,b). These results indicate that well before the epoch corresponding to z=3 significant star formation must have taken place in the galactic or proto-galactic cores where these quasars reside.
This page is
under construction. Last update: April 30, 2005.
This page created by Matthias Dietrich
Questions or comments should be sent to:dietrich@astronomy.ohio-state.edu
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