English

GTC optical imaging of extremely red 5C radio galaxies at high redshift

Astrophysics of Galaxies 2015-12-23 v1

Abstract

We investigate the nature of seven unusual radio galaxies from the 5C catalogue that were previously known to have extremely red R-K colours, and for which emission lines were previously found to be weak or absent in their optical spectra. We present and discuss u, g, or r images of these radio galaxies, obtained using the Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS) at the Gran Telescopio Canarias (GTC). We have detected all seven targets in our g-band imaging. Their optical emission is extended, and we tentatively detect a radio-optical alignment effect in this sample. A subset of our sample (three sources) shows broad-band spectral energy distributions that flatten out near the wavelength range of the g-band, implying a dominant contribution there due to young stars and/or scattered or reprocessed radiation from the active nucleus.

Keywords

Cite

@article{arxiv.1509.06800,
  title  = {GTC optical imaging of extremely red 5C radio galaxies at high redshift},
  author = {A. Humphrey and M. Villar-Martín and P. Lagos},
  journal= {arXiv preprint arXiv:1509.06800},
  year   = {2015}
}

Comments

4 pages, 3 Figures, accepted for publication in Astronomy & Astrophysics