A comprehensive view of the Virgo Stellar Stream
  Radial velocities and metallicities have been measured for 82 RR Lyrae
identified by the QUEST survey in the direction of the Virgo constellation.
Distributed over 90 sq. deg. of the sky, they lie from 4 to 23 kpc from the
Sun. Using an algorithm for finding groups in phase space and modeling the
smooth halo component in the region, we identified the 5 most significant RRLS
groups. We have examined the SEKBO and the Catalina catalog of RRLS (Prior et
al. 2009, and Drake et al. 2013), as well as the bright QUEST RRLS sample
(Vivas et al. in prep.), the catalogs of Blue Horizontal Branch stars compiled
by Sirko et al (2004) and Brown et al (2008, 2010) and the catalog of Red Giant
stars from the Spaghetti survey, for stars that may be related to the QUEST
RRLS groups. The most significant group of RRLS is the Virgo Stellar Stream
(VSS, Duffau et al 2006), group A, which is composed of at least 10 RRLS and 3
BHB stars. It has a mean distance of 19.6 kpc and a mean radial velocity Vgsr =
128 km/s, as estimated from its RRLS members. With the revised velocities
reported here, there is no longer an offset in velocity between the RRLS in the
VSS and the prominent peak in the velocities of main-sequence turnoff stars
reported by Newberg et al (2007) in the same direction and at a similar
distance (S297+63-20.5). The location in phase space of two other groups (F,H)
suggests a possible connection with the VSS, which cannot be discarded at this
point, although the turnoff colors of the VSS and group H, as identified from
Newberg et al. (2007), suggest they might be composed of different populations.
Two more groups (B,D), are found at mean distances of 19 and 5.7 kpc, and mean
radial velocities of -94 and 32 km/s. None of our groups seems to relate to Sgr
streams. The excess of stars observed in Virgo appears to be composed of
several halo substructures along the same line of sight.
