The shell game: a panoramic view of Fornax
Abstract
We present a panoramic study of the Fornax dwarf spheroidal galaxy, using data obtained as part of the VLT Survey Telescope (VST) ATLAS Survey. The data presented here -- a subset of the full survey -- uniformly cover a region of 25 square degrees centred on the galaxy, in , and -bands. This large area coverage reveals two key differences to previous studies of Fornax. First, data extending beyond the nominal tidal radius of the dwarf highlight the presence of a second distinct red giant branch population. This bluer red giant branch appears to be coeval with the horizontal branch population. Second, a shell structure located approximately 1.4 degrees from the centre of Fornax is shown to be a mis-identified background overdensity of galaxies. This last result casts further doubt on the hypothesis that Fornax underwent a gas-rich merger in its relatively recent past.
Keywords
Cite
@article{arxiv.1507.06654,
title = {The shell game: a panoramic view of Fornax},
author = {N. F. Bate and B. McMonigal and G. F. Lewis and M. J. Irwin and E. Gonzalez-Solares and T. Shanks and N. Metcalfe},
journal= {arXiv preprint arXiv:1507.06654},
year = {2015}
}
Comments
16 pages, 14 figures, accepted for publication in MNRAS, supplementary data available from first author