A search for globular clusters in more remote areas around M31 and M33 II

Journal Article · Tue Apr 01 04:00:00 EDT 2014 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/147/4/90· OSTI ID:22340304

Di Tullio Zinn, Graziella; Zinn, Robert ^[1]

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1. Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)

Using the Sloan Digital Sky Survey (SDSS), ∼900 deg{sup 2} of the sky surrounding M31 and M33 have been searched for globular clusters (GCs) that through galaxy interaction have become unbound from their parent systems and M31 (hence, intergalactic globular clusters, IGCs). This search reached a maximum of ∼500 kpc in projected galactocentric distance (R {sub gc}) from M31. Visual examination of 283,871 SDSS cutout images and of 1143 fits images yielded 320 candidates. This sample was reduced to six GCs and one likely candidate by excluding galaxies on the basis of combinations of their optical, ultraviolet, and infrared colors from the SDSS, the Galaxy Evolution Explorer satellite, and the Wide-field Infrared Survey Explorer satellite, as well as their photometric redshifts from the SDSS. Since these seven objects have 14 kpc ≤ R {sub gc} ≤ 137 kpc, they are more likely to be GCs in the halo of M31 than IGCs. They are all 'classical' as opposed to 'extended' GCs, and they provide further evidence that the remote halo of M31 (R {sub gc} ≥ 50 kpc) contains more GCs of all types and, in particular, far more 'classical' ones than the remote halo of the Milky Way.

• OSTI ID: 22340304
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 4 Vol. 147; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COLOR
DISTANCE
EVOLUTION
EXPLORER SATELLITES
GALAXY CLUSTERS
IMAGES
INFRARED SURVEYS
INTERACTIONS
MILKY WAY
RED SHIFT
ULTRAVIOLET RADIATION