PROPER MOTIONS IN KAPTEYN SELECTED AREA 103: A PRELIMINARY ORBIT FOR THE VIRGO STELLAR STREAM

Journal Article · Mon Aug 10 00:00:00 EDT 2009 · Astrophysical Journal (Online)

DOI:https://doi.org/10.1088/0004-637X/701/1/L29; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21313683

Casetti-Dinescu, Dana I; Girard, Terrence M; Van Altena, William F ^[1]; Majewski, Steven R; Carlin, Jeffrey L ^[2]; Vivas, A Katherina ^[3]; Wilhelm, Ronald ^[4]; Beers, Timothy C ^[5]

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1. Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)
2. Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)
3. Centro de Investigaciones de Astronomia (CIDA), Apartado Postal 264, Merida 5101-A (Venezuela, Bolivarian Republic of)
4. Department of Physics, Texas Tech University, Lubbock, TX 79409 (United States)
5. Department of Physics and Astronomy, Center for the Study of Cosmic Evolution (CSCE), and Joint Institution for Nuclear Astrophysics (JINA), Michigan State University, East Lansing, MI 48824 (United States)

We present absolute proper motions in Kapteyn Selected Area (SA) 103. This field is located 7 deg. 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 {approx}11 kpc and an apocenter of {approx}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.

• OSTI ID: 21313683
• Journal Information: Astrophysical Journal (Online), Vol. 701, Issue 1; Other Information: DOI: 10.1088/0004-637X/701/1/L29; Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-4357
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
GALAXIES
ORBITS
PROPER MOTION
RADIAL VELOCITY
STARS