The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XVIII. Proper-motion kinematics of multiple stellar populations in the core regions of NGC 6352. (arXiv:1902.02787v1 [astro-ph.SR])

The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XVIII. Proper-motion kinematics of multiple stellar populations in the core regions of NGC 6352. (arXiv:1902.02787v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Libralato_M/0/1/0/all/0/1">M. Libralato</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bellini_A/0/1/0/all/0/1">A. Bellini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Piotto_G/0/1/0/all/0/1">G. Piotto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nardiello_D/0/1/0/all/0/1">D. Nardiello</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marel_R/0/1/0/all/0/1">R. P. van der Marel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anderson_J/0/1/0/all/0/1">J. Anderson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bedin_L/0/1/0/all/0/1">L. R. Bedin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vesperini_E/0/1/0/all/0/1">E. Vesperini</a>

We present the analysis of the radial distributions and kinematic properties
of the multiple stellar populations (mPOPs) hosted in the globular cluster (GC)
NGC 6352 as part of the Hubble Space Telescope (HST) “UV Legacy Survey of
Galactic Globular Clusters” program. NGC 6352 is one of the few GCs for which
the mPOP tagging in appropriate color-magnitude diagrams is clear in all
evolutionary sequences. We computed high-precision stellar proper motions for
the stars from the cluster’s core out to 75 arcsec ($sim$1.5 core radii, or
$sim$0.6 half-light radii). We find that, in the region explored, first- and
second-generation stars share the same radial distribution and kinematic
properties. Velocity dispersions, anisotropy radial profiles, differential
rotation, and level of energy equipartition, all suggest that NGC 6352 is
probably in an advanced evolutionary stage, and any possible difference in the
structural and kinematic properties of its mPOPs have been erased by dynamical
processes in the core of the cluster. We also provide an estimate of the mass
of blue stragglers and of main-sequence binaries through kinematics alone. In
general, in order to build a complete dynamical picture of this and other GCs,
it will be essential to extend the analyses presented in this paper to the GCs’
outer regions where some memories of the initial differences in the mPOP
properties, and those imprinted by dynamical processes, might still be present.

We present the analysis of the radial distributions and kinematic properties
of the multiple stellar populations (mPOPs) hosted in the globular cluster (GC)
NGC 6352 as part of the Hubble Space Telescope (HST) “UV Legacy Survey of
Galactic Globular Clusters” program. NGC 6352 is one of the few GCs for which
the mPOP tagging in appropriate color-magnitude diagrams is clear in all
evolutionary sequences. We computed high-precision stellar proper motions for
the stars from the cluster’s core out to 75 arcsec ($sim$1.5 core radii, or
$sim$0.6 half-light radii). We find that, in the region explored, first- and
second-generation stars share the same radial distribution and kinematic
properties. Velocity dispersions, anisotropy radial profiles, differential
rotation, and level of energy equipartition, all suggest that NGC 6352 is
probably in an advanced evolutionary stage, and any possible difference in the
structural and kinematic properties of its mPOPs have been erased by dynamical
processes in the core of the cluster. We also provide an estimate of the mass
of blue stragglers and of main-sequence binaries through kinematics alone. In
general, in order to build a complete dynamical picture of this and other GCs,
it will be essential to extend the analyses presented in this paper to the GCs’
outer regions where some memories of the initial differences in the mPOP
properties, and those imprinted by dynamical processes, might still be present.

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