Open AccessSpatial and velocity clumping in a Sloan Digital Sky Survey blue horizontal branch star catalogue
Author(s) -
Clewley L.,
Kinman T. D.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society: letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.067
H-Index - 122
eISSN - 1745-3933
pISSN - 1745-3925
DOI - 10.1111/j.1745-3933.2006.00198.x
Subject(s) - physics , sky , stars , astrophysics , rr lyrae variable , horizontal branch , astronomy , sagittarius , halo , galaxy , radial velocity , proper motion , dwarf galaxy , globular cluster
We present evidence for eight new clumps of blue horizontal branch stars discovered in a catalogue of these stars compiled from the Sloan Digital Sky Survey by Sirko et al. and published in 2004. Clumps are identified by selecting pairs of stars separated by distances ≤2 kpc and with differences in galactocentric radial velocities <25 km s −1 . Each clump contains four or more stars. Four of the clumps have supporting evidence: two of them also contain overdensities of RR Lyrae stars which makes their reality very likely. At least one of the clumps is likely to be associated with the tidal debris of the Sagittarius dwarf spheroidal galaxy. We emphasize that more accurate observations of the radial velocities or proper motions of the stars in the clumps, as well as the identification of other halo stars in these regions, are required to establish the reality of the remaining clumps.