Bibcode
DOI
Duffau, Sonia; Zinn, Robert; Vivas, A. Katherina; Carraro, Giovanni; Méndez, René A.; Winnick, Rebeccah; Gallart, Carme
Bibliographical reference
The Astrophysical Journal, Volume 636, Issue 2, pp. L97-L100.
Advertised on:
1
2006
Journal
Citations
140
Refereed citations
122
Description
Eighteen RR Lyrae variables (RRLs) that lie in the ``12.4h clump''
identified by the Quasar Equatorial Survey Team (QUEST) have been
observed spectroscopically to measure their radial velocities and metal
abundances. Ten blue horizontal branch (BHB) stars identified by the
Sloan Digital Sky Survey (SDSS) were added to this sample. Six of the
nine stars in the densest region of the clump have a mean radial
velocity in the Galactic rest frame (Vgsr) of 99.8 and
σ=17.3 km s-1, which is slightly smaller than the
average error of the measurements. The whole sample contains eight RRLs
and five BHB stars that have values of Vgsr suggesting
membership in this stream. For seven of these RRLs, the measurements of
[Fe/H], which have an internal precision of 0.08 dex, yield
<[Fe/H]>=-1.86 and σ=0.40. These values suggest that the
stream is a tidally disrupted dwarf spheroidal galaxy of low luminosity.
Photometry from the database of the SDSS indicates that this stream
covers at least 106 deg2 of the sky in the constellation
Virgo. The name Virgo stellar stream is suggested.