We present an imaging study of the black hole binary candidate SDSS J1536+0441 (z=0.3893), based on deep, high resolution VzK images collected at the ESO/VLT. The images clearly show an asymmetric elongation, indicating the presence of a companion source at ~1" (~5 kpc projected distance) East from the quasar. The host galaxy of the quasar is marginally resolved. We find that the companion source is a luminous galaxy, the light profile of which suggests the presence of an unresolved, faint nucleus (either an obscured AGN or a compact stellar bulge). The study of the environment around the quasar indicates the occurrence of a significant over-density of galaxies with a redshift compatible with z~0.4. This suggests that it resides in a moderately rich cluster of galaxies.
@article{arxiv.0907.5414,
title = {Probing the nature of the massive black hole binary candidate SDSS J1536+0441},
author = {R. Decarli and M. Dotti and R. Falomo and A. Treves and M. Colpi and J. K. Kotilainen and C. Montuori and M. Uslenghi},
journal= {arXiv preprint arXiv:0907.5414},
year = {2015}
}
Comments
4 figures, 1 table. Accepted for publication in ApJ Letters