The globular cluster NGC7492 and the Sagittarius tidal stream: Together but unmixed
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Fecha
2018-03
Profesor/a Guía
Facultad/escuela
Idioma
en
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Editor
Oxford University Press
Nombre de Curso
Licencia CC
Licencia CC
Resumen
We have derived from VIMOS spectroscopy the radial velocities for a sample of 71 stars selected from CFHT/Megacam photometry around the Galactic globular cluster NGC7492. In the resulting velocity distribution, it is possible to distinguish two relevant non-Galactic kinematic components along the same line of sight: a group of stars at 〈vr〉~125 km s-1 which is compatible with the velocity of the old leading arm of the Sagittarius tidal stream, and a larger number of objects at 〈 vr〉 ~ -110 km s-1 that might be identified as members of the trailing wrap of the same stream. The systemic velocity of NGC7492 set at vr ~-177 km s-1 differs significantly from that of both components, thus our results confirm that this cluster is not one of the globular clusters deposited by the Sagittarius dwarf spheroidal in the Galactic halo, even if it is immersed in the stream. A group of stars with 〈 vr〉 ~ - 180 km s-1 might be comprised of cluster members along one of the tidal tails of NGC7492. © 2017 The Author(s).
Notas
Indexación Scopus
Palabras clave
Globular Clusters, Halo, Gaia
Citación
Monthly Notices of the Royal Astronomical Society Volume 474, Issue 4, Pages 4766 - 47711 March 2018
DOI
10.1093/mnras/stx3001