Bibcode
Mackey, A. D.; Beasley, M. A.; Leaman, R.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society: Letters, Volume 460, Issue 1, p.L114-L118
Advertised on:
7
2016
Citations
9
Refereed citations
8
Description
We present Gemini Multi-Object Spectrograph (GMOS) imaging of 12
candidate intergalactic globular clusters (IGCs) in the Local Group,
identified in a recent survey of the Sloan Digital Sky Survey (SDSS)
footprint by di Tullio Zinn & Zinn. Our image quality is
sufficiently high, at ˜0.4-0.7 arcsec, that we are able to
unambiguously classify all 12 targets as distant galaxies. To reinforce
this conclusion we use GMOS images of globular clusters in the M31 halo,
taken under very similar conditions, to show that any genuine clusters
in the putative IGC sample would be straightforward to distinguish.
Based on the stated sensitivity of the di Tullio Zinn & Zinn search
algorithm, we conclude that there cannot be a significant number of IGCs
with MV ≤ -6 lying unseen in the SDSS area if their
properties mirror those of globular clusters in the outskirts of M31 -
even a population of 4 would have only a ≈1 per cent chance of
non-detection.