The Tale of the Milky Way Globular Cluster NGC 6362 — I. The Orbit and its possible extended star debris features as revealed by Gaia DR2. (arXiv:1909.02016v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Kundu_R/0/1/0/all/0/1">Richa Kundu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fernandez_Trincado_J/0/1/0/all/0/1">José G. Fernández-Trincado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Minniti_D/0/1/0/all/0/1">Dante Minniti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Singh_H/0/1/0/all/0/1">Harinder P. Singh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Moreno_E/0/1/0/all/0/1">Edmundo Moreno</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reyle_C/0/1/0/all/0/1">Céline Reylé</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Robin_A/0/1/0/all/0/1">Annie C. Robin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Soto_M/0/1/0/all/0/1">Mario Soto</a>
We report the identification of possible extended star debris candidates
beyond the cluster tidal radius of NGC 6362 based on the second {it Gaia} data
release ({it Gaia} DR2). We found 259 objects possibly associated with the
cluster lying in the vicinity of the giant branch and 1–2 magnitudes
fainter/brighter than the main-sequence turn-off in the cluster color-magnitude
diagram and which cover an area on the sky of $sim$4.1 deg$^{2}$ centered on
the cluster. We traced back the orbit of NGC 6362 in a realistic Milky-Way
potential, using the texttt{GravPot16} package, for 3 Gyrs. The orbit shows
that the cluster shares similar orbital properties as the inner disk, having
peri-/apo-galactic distances, and maximum vertical excursion from the Galactic
plane inside the corotation radius (CR), moving inwards from CR radius to visit
the inner regions of the Milky Way. The dynamical history of the cluster
reveals that it has crossed the Galactic disk several times in its lifetime and
has recently undergone a gravitational shock, $sim 15.9$ Myr ago, suggesting
that less than 0.1% of its mass has been lost during the current disk-shocking
event. Based on the cluster’s orbit and position in the Galaxy, we conclude
that the possible extended star debris candidates are a combined effect of the
shocks from the Galactic disk and evaporation from the cluster. Lastly, the
evolution of the vertical component of the angular momentum shows that the
cluster is strongly affected dynamically by the Galactic bar potential.
We report the identification of possible extended star debris candidates
beyond the cluster tidal radius of NGC 6362 based on the second {it Gaia} data
release ({it Gaia} DR2). We found 259 objects possibly associated with the
cluster lying in the vicinity of the giant branch and 1–2 magnitudes
fainter/brighter than the main-sequence turn-off in the cluster color-magnitude
diagram and which cover an area on the sky of $sim$4.1 deg$^{2}$ centered on
the cluster. We traced back the orbit of NGC 6362 in a realistic Milky-Way
potential, using the texttt{GravPot16} package, for 3 Gyrs. The orbit shows
that the cluster shares similar orbital properties as the inner disk, having
peri-/apo-galactic distances, and maximum vertical excursion from the Galactic
plane inside the corotation radius (CR), moving inwards from CR radius to visit
the inner regions of the Milky Way. The dynamical history of the cluster
reveals that it has crossed the Galactic disk several times in its lifetime and
has recently undergone a gravitational shock, $sim 15.9$ Myr ago, suggesting
that less than 0.1% of its mass has been lost during the current disk-shocking
event. Based on the cluster’s orbit and position in the Galaxy, we conclude
that the possible extended star debris candidates are a combined effect of the
shocks from the Galactic disk and evaporation from the cluster. Lastly, the
evolution of the vertical component of the angular momentum shows that the
cluster is strongly affected dynamically by the Galactic bar potential.
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