Journal Article

Using the minimum spanning tree to trace mass segregation

Richard J. Allison, Simon P. Goodwin, Richard J. Parker, Simon F. Portegies Zwart, Richard De Grijs and M. B. N. Kouwenhoven

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 395, issue 3, pages 1449-1454
Published in print May 2009 | ISSN: 0035-8711
Published online May 2009 | e-ISSN: 1365-2966 | DOI:
Using the minimum spanning tree to trace mass segregation

Show Summary Details


We present a new method to detect and quantify mass segregation in star clusters. It compares the minimum spanning tree (MST) of massive stars with that of random stars. If mass segregation is present, the MST length of the most massive stars will be shorter than that of random stars. This difference can be quantified (with an associated significance) to measure the degree of mass segregation. We test the method on simulated clusters in both 2D and 3D and show that the method works as expected.

We apply the method to the Orion Nebula Cluster (ONC) and show that the method is able to detect the mass segregation in the Trapezium with a ‘mass segregation ratio (MSR)’ΛMSR= 8.0 ± 3.5 (where ΛMSR= 1 is no mass segregation) down to 16 M, and also that the ONC is mass segregated at a lower level (∼2.0 ± 0.5) down to 5 M. Below 5 M we find no evidence for any further mass segregation in the ONC.

Keywords: methods: data analysis

Journal Article.  4204 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.