Looking for phasespace structures in starforming regions: an MSTbased methodology
Abstract
We present a method for analysing the phase space of starforming regions. In particular we are searching for clumpy structures in the 3D subspace formed by two position coordinates and radial velocity. The aim of the method is the detection of kinematic segregated radial velocity groups, that is, radial velocity intervals whose associated stars are spatially concentrated. To this end we define a kinematic segregation index, tilde{Λ }(RV), based on the Minimum Spanning Tree graph algorithm, which is estimated for a set of radial velocity intervals in the region. When tilde{Λ }(RV) is significantly greater than 1 we consider that this bin represents a grouping in the phase space. We split a starforming region into radial velocity bins and calculate the kinematic segregation index for each bin, and then we obtain the spectrum of kinematic groupings, which enables a quick visualization of the kinematic behaviour of the region under study. We carried out numerical models of different configurations in the subspace of the phase space formed by the coordinates and the that various case studies illustrate. The analysis of the test cases demonstrates the potential of the new methodology for detecting different kind of groupings in phase space.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 March 2016
 DOI:
 10.1093/mnras/stv2822
 arXiv:
 arXiv:1512.01182
 Bibcode:
 2016MNRAS.456.2900A
 Keywords:

 methods: data analysis;
 methods: statistical;
 astronomical data bases: miscellaneous;
 stars: formation;
 stars: kinematics and dynamics;
 open clusters and associations: general;
 Astrophysics  Instrumentation and Methods for Astrophysics;
 Astrophysics  Astrophysics of Galaxies
 EPrint:
 8 pages, 4 figures, accepted for publication in MNRAS