Metallicity of the high-redshift Universe traced by radio galaxies
Abstract
We investigate the metallicity of the narrow line regions (NLRs) of high-z radio galaxies (HzRGs), using new deep optical spectra of 9 HzRGs obtained with FORS2 on VLT and data from the literature. To estimate the metallicity of NLRs we focus on the Civ/Heii and Ciii]/Civ flux ratios. Based on comparison between the observed emission-line flux ratios and the prediction of our photoionization model calculations, we find no significant metallicity evolution in NLRs of HzRGs, up to z ~ 4. We discuss the possibility that massive galaxies had almost completed the major epoch of the star formation in the very high-z universe (z > 5).
- Publication:
-
Chemical Abundances in the Universe: Connecting First Stars to Planets
- Pub Date:
- March 2010
- DOI:
- 10.1017/S1743921310000499
- Bibcode:
- 2010IAUS..265..179M
- Keywords:
-
- galaxies: active;
- galaxies: evolution;
- quasars: emission lines;
- quasars: general