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تسجيل مستخدم جديدSailing on the Sagittarius Stream with Gaia DR2. I. The globular cluster NGC5634
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M. Bellazzini
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We use Gaia DR2 data to show that the globular cluster NGC5634 is physically associated with an arm of the Sagittarius Stream, the huge system of tidal tails created by the ongoing disruption of the Sagittarius dwarf spheroidal galaxy (Sgr dSph). Two additional arms of the Stream are also detected along the same line of sight, at different distances. We show that the Sgr Stream stars surrounding NGC5634 are more metal-poor, on average, than those found in the more distant Stream arm lying behind the cluster and in the main body of Sgr~dSph, confirming that a significant metallicity (and, presumably, age) gradient is present along the Stream. This analysis demonstrates the potential of the Gaia DR2 catalogue to directly verify if a cluster is physically associated to the Stream or not, without the need to rely on models of the tidal disruption of this system. [Withdrawn: see comments]
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We reconsider the case for the association of Galactic globular clusters (GCs) to the tidal stream of the Sagittarius dwarf spheroidal galaxy (Sgr dSph), using Gaia DR2 data. We use RR Lyrae to trace the stream in 6D and we select clusters matching t
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