Investigating Galactic binary cluster candidates with Gaia EDR3

Abstract

A number of stellar open cluster (OC) pairs in the Milky Way occupy similar positions in the phase space (coordinates, parallax and proper motions) and therefore may constitute physically interacting systems. The characterization of such objects based on observational data is a fundamental step towards a proper understanding of their physical status and to investigate cluster pair formation in the Galaxy. In this work, we employed Gaia EDR3 data to investigate a set of 16 OCs distributed as seven stellar aggregates. We determined structural parameters and applied a decontamination technique that allowed to obtain unambiguous lists of member stars. The studied OCs span Galactocentric distances and ages in the ranges ~7 < $R_G$ (kpc) < ~11 and 7.3 <= log t <= 9.2. Eight OCs were found to constitute 4 gravitationally bound pairs (NGC5617-Trumpler22, Collinder394-NGC6716, Ruprecht100-Ruprecht101, NGC659-NGC663, the latter being a dynamically unevolved binary) and other 4 clusters constitute 2 interacting, but gravitationally unbound, pairs (King16-Berkeley4, NGC2383-NGC2384, the latter being a dissolving OC). Other 4 OCs (Dias1, Pismis19, Czernik20, NGC1857) seem not associated to any stellar aggregates. Apparently, clusters within bound and dynamically evolved pairs tend to present ratios of half-light to tidal radius larger than single clusters located at similar $R_G$, suggesting that mutual tidal interactions may possibly affect their structural parameters. Unbound or dynamically unevolved systems seems to present less noticeable signature of tidal forces on their structure. Moreover, the core radius seems more importantly correlated with the clusters' internal dynamical relaxation process.

arXiv commentAccepted for publication in MNRAS

References in corpus (57)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Gaia Data Release 2. Summary of the contents and survey properties
• On the variation of the Initial Mass Function
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• The SIMBAD astronomical database
• Gaia Early Data Release 3: The astrometric solution
• Young massive star clusters
• Local stellar kinematics from Hipparcos data
• Gaia Early Data Release 3: Parallax bias versus magnitude, colour, and position
• New catalogue of optically visible open clusters and candidates
• Gaia Early Data Release 3: Photometric content and validation
• Dynamical evolution of star clusters in tidal fields
• Gaia Data Release 2: using Gaia parallaxes
• Gaia Early Data Release 3 -- Catalogue validation
• The Evolution of Globular Clusters in the Galaxy
• Updated parameters of 1743 open clusters based on Gaia DR2
• Clusters and mirages: cataloguing stellar aggregates in the Milky Way
• Hunting for open clusters in \textit{Gaia} DR2: $582$ new OCs in the Galactic disc
• The Origin of OB Runaway Stars
• The life cycle of star cluster in a tidal field
• Dynamical evolution of star forming regions
• Lifetimes of tidally limited star clusters with different radii
• Residual gas expulsion from young globular clusters
• Stellar Rotation in Young Clusters. I. Evolution of Projected Rotational Velocity Distributions
• The effect of spiral arm passages on the evolution of stellar clusters
• Spatial dependence of 2MASS luminosity and mass functions in the old open cluster NGC 188
• Evidence for two populations of Galactic globular clusters from the ratio of their half-mass to Jacobi radii
• Integrated Near-Infrared Colors of Star Clusters: Analysis of the Stochastic Effects on the IMF
• Double or binary: on the multiplicity of open star clusters
• Validation of the accuracy and precision of Gaia EDR3 parallaxes with globular clusters
• A statistical study of binary and multiple clusters in the LMC
• Fundamental parameters for 45 open clusters with Gaia DR2, an improved extinction correction and a metallicity gradient prior
• Formation of star clusters in the LMC and SMC. I. Preliminary results on cluster formation from colliding gas clouds
• Mergers of Globular Clusters
• The Size Scale of Star Clusters
• A critical look at the merger scenario to explain multiple populations and rotation in iron-complex globular clusters
• The dynamical fate of binary star clusters in the Galactic tidal field
• The Evolution of Primordial Binary Open Star Clusters: Mergers, Shredded Secondaries and Separated Twins
• Dissolving star cluster candidates
• The Mass Profile of the Milky Way to the Virial Radius from the Illustris Simulation
• What happened before? -- The disks around the precursors of young Herbig Ae/Be stars
• First phase space portrait of a hierarchical stellar structure in the Milky Way
• The VISCACHA survey -- II. Structure of star clusters in the Magellanic Clouds periphery
• Characterizing dynamical states of Galactic open clusters with Gaia DR2
• The dynamical origin of multiple populations in intermediate-age clusters in the Magellanic Clouds
• Characterizing low contrast Galactic open clusters with GAIA DR2
• Binary open clusters in the Milky Way: photometric and spectroscopic analysis of NGC 5617 and Trumpler 22
• Investigating dynamical properties of evolved Galactic open clusters
• Roche volume filling and the dissolution of open star clusters
• SIRIUS project II: a new tree-direct hybrid code for smoothed particle hydrodynamics/N-body simulations of star clusters
• Multi-colour photometry and Gaia EDR3 astrometry of two couples of binary clusters (NGC 5617 and Trumpler 22) and (NGC 3293 and NGC 3324)
• Aggregates of clusters in the Gaia data
• Roche volume filling of star clusters in the Milky Way
• Early dynamics and violent relaxation of multi-mass rotating star clusters
• The Formation of Binary Star Clusters in the Milky Way and Large Magellanic Cloud
• Three candidate double clusters in the LMC: truth or dare?
• Sejong open cluster survey (SOS) - V. The active star forming region Sh 2-255 -- 257

Cited by in corpus (9)

• Hunting for Neighboring Open Clusters with Gaia DR3: 101 New Open Clusters within 500 pc
• Binary open clusters in the Gaia data
• Binary and Grouped Open Clusters: A New Catalogue
• The cosmic waltz of Coma Berenices and Latyshev 2 (Group X). Membership, phase-space structure, mass, and energy distributions
• Unveiling the Binary Nature of NGC 2323
• Star-by-star dynamical evolution of the physical pair of the Collinder 135 and UBC 7 open clusters
• Open superclusters I: The most populated primordial groups of open clusters in the third quadrant of the Galactic disc
• AstroSat/UVIT Study of NGC 663: First detection of Be+sdOB systems in a young star cluster
• On the Encounter Rate of Open Star Clusters