TY - JOUR
T1 - 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
AU - Kundu, Richa
AU - Fernández-Trincado, José G.
AU - Minniti, Dante
AU - Singh, Harinder P.
AU - Moreno, Edmundo
AU - Reylé, Céline
AU - Robin, Annie C.
AU - Soto, Mario
N1 - Funding Information:
The authors would like to thank the anonymous referee for her/his constructive comments and improvements, making this a better paper. RK is thankful to the Council of Scientific and Industrial Research, New Delhi, for a Senior Research Fellowship (SRF)
Funding Information:
The authors would like to thank the anonymous referee for her/his constructive comments and improvements, making this a better paper. RK is thankful to the Council of Scientific and Industrial Research, New Delhi, for a Senior Research Fellowship (SRF) (File number: 09/045 (1414)/2016-EMR-I). JGF-T is supported by FONDECYT No. 3180210. DM gratefully acknowledges support provided by the BASAL Center for Astrophysics and Associated Technologies (CATA) through grant AFB 170002, and the Ministry for the Economy, Development and Tourism, Programa Iniciativa Cient?fica Milenio grant IC120009, awarded to the Millennium Institute of Astrophysics (MAS), and from project Fondecyt No. 1170121. HPS and RK are thankful to the Council of Scientific and Industrial Research, New Delhi, for the grants-in-aid (Ref. No. 03(1428)/18/EMR-II). RK and DM are also very grateful for the hospitality of the Vatican Observatory, where this work was started. EM acknowledges support from <0:funding-source >UNAM/PAPII T</0:funding-source> grant IN105916. Funding for the GRAVPOT16 software has been provided by the Centre national d??tudes spatiales (CNES) through grant 0101973 and UTINAM Institute of the Universit? de Franche-Comt?, supported by the R?gion de Franche-Comt? and Institut des Sciences de l?Univers (INSU). Simulations have been executed on computers from the Utinam Institute of the Universit? de Franche-Comt?, supported by the R?gion de Franche-Comt? and Institut des Sciences de l?Univers (INSU), and on the supercomputer facilities of the M?socentre de calcul de Franche-Comt?. This work has made use of results from the European Space Agency (ESA) space mission Gaia, the data from which were processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. The Gaia mission website is http: //www.cosmos.esa.int/gaia.
Publisher Copyright:
© Crown copyright 2019.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - We report the identification of possible extended star debris candidates beyond the cluster tidal radius of NGC 6362 based on the second Gaia data release (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 colour–magnitude diagram and which cover an area on the sky of ∼4.1 deg2 centred on the cluster. We traced back the orbit of NGC 6362 in a realistic Milky Way potential, using the GRAVPOT16 package, for 3 Gyr. The orbit shows that the cluster shares similar orbital properties as the inner disc, having peri-/apogalactic 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 disc several times in its lifetime and has recently undergone a gravitational shock, ∼15.9 Myr ago, suggesting that less than 0.1 per cent of its mass has been lost during the current disc-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 disc 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.
AB - We report the identification of possible extended star debris candidates beyond the cluster tidal radius of NGC 6362 based on the second Gaia data release (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 colour–magnitude diagram and which cover an area on the sky of ∼4.1 deg2 centred on the cluster. We traced back the orbit of NGC 6362 in a realistic Milky Way potential, using the GRAVPOT16 package, for 3 Gyr. The orbit shows that the cluster shares similar orbital properties as the inner disc, having peri-/apogalactic 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 disc several times in its lifetime and has recently undergone a gravitational shock, ∼15.9 Myr ago, suggesting that less than 0.1 per cent of its mass has been lost during the current disc-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 disc 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.
KW - Dynamics
KW - Galaxy: kinematics
KW - Globular clusters: individual: NGC 6362
UR - http://www.scopus.com/inward/record.url?scp=85075261086&partnerID=8YFLogxK
U2 - 10.1093/mnras/stz2500
DO - 10.1093/mnras/stz2500
M3 - Article
AN - SCOPUS:85075261086
VL - 489
SP - 4565
EP - 4573
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 1745-3925
IS - 4
ER -