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Description
We analyze the 3D morphology and kinematics of 13 open clusters (OCs) located within 500pc of the Sun, using Gaia} EDR3 and kinematic data from literature. Members of OCs are identified using the unsupervised machine learning method StarGO, using 5D parameters (X, Y, Z, {mu}_{alpha}cos{delta}, {mu}_{delta}). The OC sample covers an age range of 25Myr-2.65Gyr. We correct the asymmetric distance distribution due to the parallax error using Bayesian inversion. The uncertainty in the corrected distance for a cluster at 500pc is 3.0-6.3pc, depending on the intrinsic spatial distribution of its members. We determine the 3D morphology of the OCs in our sample and fit the spatial distribution of stars within the tidal radius in each cluster with an ellipsoid model. The shapes of the OCs are well-described with oblate spheroids (NGC 2547, NGC 2516, NGC 2451A, NGC 2451B, NGC 2232), prolate spheroids (IC 2602, IC 4665, NGC 2422, Blanco 1, Coma Berenices), or triaxial ellipsoids (IC 2391, NGC 6633, NGC 6774). The semi-major axis of the fitted ellipsoid is parallel to the Galactic plane for most clusters. Elongated filament-like substructures are detected in three young clusters (NGC 2232, NGC 2547, NGC 2451B), while tidal-tail-like substructures (tidal tails) are found in older clusters (NGC 2516, NGC 6633, NGC 6774, Blanco 1, Coma Berenices). Most clusters may be super-virial and expanding. N-body models of rapid gas expulsion with an SFE of ~1/3 are consistent with clusters more massive than 250M_{sun}_, while clusters less massive than 250M_{sun}_ tend to agree with adiabatic gas expulsion models. Only six OCs (NGC 2422, NGC 6633, and NGC 6774, NGC 2232, Blanco 1, Coma Berenices) show clear signs of mass segregation.
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