No sign (yet) of intergalactic globular clusters in the Local Group

A. D. Mackey; M. A. Beasley; R. Leaman

doi:10.1093/mnrasl/slw076

No sign (yet) of intergalactic globular clusters in the Local Group

A. D. Mackey^*, M. A. Beasley, R. Leaman

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

7 Citations (Scopus)

Abstract

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 M_V ≤ -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.

Original language	English
Pages (from-to)	L114-L118
Journal	Monthly Notices of the Royal Astronomical Society: Letters
Volume	460
Issue number	1
DOIs	https://doi.org/10.1093/mnrasl/slw076
Publication status	Published - 21 Jul 2016

Access to Document

10.1093/mnrasl/slw076

Cite this

@article{a5474506dbf64b0e8b467874221a1827,

title = "No sign (yet) of intergalactic globular clusters in the Local Group",

abstract = "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.",

keywords = "Globular clusters: general, Local Group",

author = "Mackey, {A. D.} and Beasley, {M. A.} and R. Leaman",

year = "2016",

month = jul,

day = "21",

doi = "10.1093/mnrasl/slw076",

language = "English",

volume = "460",

pages = "L114--L118",

journal = "Monthly Notices of the Royal Astronomical Society: Letters",

issn = "1745-3925",

publisher = "Oxford University Press",

number = "1",

}

TY - JOUR

T1 - No sign (yet) of intergalactic globular clusters in the Local Group

AU - Mackey, A. D.

AU - Beasley, M. A.

AU - Leaman, R.

PY - 2016/7/21

Y1 - 2016/7/21

N2 - 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.

AB - 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.

KW - Globular clusters: general

KW - Local Group

UR - http://www.scopus.com/inward/record.url?scp=84978437361&partnerID=8YFLogxK

U2 - 10.1093/mnrasl/slw076

DO - 10.1093/mnrasl/slw076

M3 - Article

SN - 1745-3925

VL - 460

SP - L114-L118

JO - Monthly Notices of the Royal Astronomical Society: Letters

JF - Monthly Notices of the Royal Astronomical Society: Letters

IS - 1

ER -

No sign (yet) of intergalactic globular clusters in the Local Group

Abstract

Access to Document

Other files and links

Fingerprint

Cite this