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Deep VLT spectroscopy of high redshift radio galaxy MRC 2104-242: Evidence for a metallicity gradient

R. Overzier·H. Rottgering·J. Kurk·C. De Breuck
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Abstract

In this contribution we will present deep VLT spectroscopy observations of the giant emission line halo around the z=2.49 radio galaxy MRC 2104-242. The morphology of the halo is dominated by two spatially resolved regions. Lya is extended by >12" along the radio axis, C IV and He II are extended by ~8". The overall spectrum is typical for that of high redshift radio galaxies. Interestingly, N V is present in the spectrum of the region associated with the center of the galaxy hosting the radio source, the northern region, while absent in the southern region. Using a simple photoionization model, the difference in N V can be explained due to a metallicity gradient within the halo. This is consistent with a scenario in which the halo is formed by a massive cooling flow or originates from the debris of the merging of two or more galaxies. However, also other mechanisms such as jet-cloud interactions or starburst-winds could be important.

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R. Overzier, H. Rottgering, J. Kurk, C. De Breuck. 2001-02-21. Deep VLT spectroscopy of high redshift radio galaxy MRC 2104-242: Evidence for a metallicity gradient. https://arxiv.org/abs/astro-ph/0102364

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