TY - JOUR
T1 - Proper motions in Kapteyn selected area 103
T2 - A preliminary orbit for the virgo stellar stream
AU - Casetti-Dinescu, Dana I.
AU - Girard, Terrence M.
AU - Majewski, Steven R.
AU - Vivas, A. Katherina
AU - Wilhelm, Ronald
AU - Carlin, Jeffrey L.
AU - Beers, Timothy C.
AU - Van Altena, William F.
PY - 2009
Y1 - 2009
N2 - We present absolute proper motions in Kapteyn Selected Area (SA) 103. This field is located 7° west of the center of the Virgo Stellar Stream (VSS), and has a well-defined main sequence representing the stream. In SA 103, we identify one RR Lyrae star as a member of the VSS, according to its metallicity, radial velocity, and distance. VSS candidate turnoff and subgiant stars have proper motions consistent with that of the RR Lyrae star. The three-dimensional velocity data imply an orbit with a pericenter of ∼11 kpc and an apocenter of ∼90 kpc. Thus, the VSS comprises tidal debris found near the pericenter of a highly destructive orbit. Examining the six globular clusters at distances larger than 50 kpc from the Galactic center, and the proposed orbit of the VSS, we find one tentative association, NGC 2419. We speculate that NGC 2419 is possibly the nucleus of a disrupted system of which the VSS is a part.
AB - We present absolute proper motions in Kapteyn Selected Area (SA) 103. This field is located 7° west of the center of the Virgo Stellar Stream (VSS), and has a well-defined main sequence representing the stream. In SA 103, we identify one RR Lyrae star as a member of the VSS, according to its metallicity, radial velocity, and distance. VSS candidate turnoff and subgiant stars have proper motions consistent with that of the RR Lyrae star. The three-dimensional velocity data imply an orbit with a pericenter of ∼11 kpc and an apocenter of ∼90 kpc. Thus, the VSS comprises tidal debris found near the pericenter of a highly destructive orbit. Examining the six globular clusters at distances larger than 50 kpc from the Galactic center, and the proposed orbit of the VSS, we find one tentative association, NGC 2419. We speculate that NGC 2419 is possibly the nucleus of a disrupted system of which the VSS is a part.
KW - Galaxy: halo
KW - Galaxy: kinematics and dynamics
KW - Galaxy: structure
UR - https://www.scopus.com/pages/publications/73449120111
UR - https://www.scopus.com/pages/publications/73449120111#tab=citedBy
U2 - 10.1088/0004-637X/701/1/L29
DO - 10.1088/0004-637X/701/1/L29
M3 - Article
AN - SCOPUS:73449120111
SN - 0004-637X
VL - 701
SP - L29-L33
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1 PART 2
ER -