EDP Sciences
Free access

This article has an erratum: [erratum]

Volume 367, Number 3, March I 2001
Page(s) L5 - L8
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20010041

A&A 367, L5-L8 (2001)
DOI: 10.1051/0004-6361:20010041

Deep VLT spectroscopy of the $\vec{z}=$ 2.49 radio galaxy MRC 2104-242

Evidence for a metallicity gradient in its extended emission line region
R. A. Overzier, H. J. A. Röttgering, J. D. Kurk and C. De Breuck

Sterrewacht Leiden, PO Box 9513, 2300 RA, Leiden, The Netherlands

(Received 10 November 2000 / Accepted 8 January 2000 )


We present spectroscopic observations of the rest-frame UV line emission around radio galaxy MRC 2104-242 at z=2.49, obtained with FORS1 on VLT Antu. The morphology of the halo is dominated by two spatially resolved regions. Ly$\alpha$ is extended by >12´´along the radio axis, C $\RM IV$ and He $\RM II$ are extended by $\sim$8´´. The overall spectrum is typical for that of high redshift radio galaxies. The most striking spatial variation is that N $\RM 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. Assuming that the gas is photoionized by a hidden quasar, the difference in N $\RM V $ emission can be explained by a metallicity gradient within the halo, with the northern region having a metallicity of $Z\approx1.5 Z_{\odot}$ and $Z\leq0.4 Z_{\odot}$ for the southern region. This is consistent with a scenario in which the gas is associated with a massive cooling flow or originates from the debris of the merging of two or more galaxies.

Key words: cosmology: early Universe -- galaxies: active -- galaxies: evolution -- galaxies: individual: MRC 2104 -- 242 -- galaxies: kinematics and dynamics

Offprint request: R. A. Overzier, overzier@strw.leidenuniv.nl

SIMBAD Objects in preparation

© ESO 2001