Using molecular gas observations to guide initial conditions for star cluster simulations

Monthly Notices of the Royal Astronomical Society, vol. 519, pp. 4142–4151

Abstract

ABSTRACT The earliest evolution of star clusters involves a phase of co-existence of both newly formed stars, and the gas from which they are forming. Observations of the gas in such regions provide a wealth of data that can inform the simulations which are needed to follow the evolution of such objects forward in time. We present a method for transforming the observed gas properties into initial conditions for simulations that include gas, stars, and ongoing star formation. We demonstrate our technique using the Orion Nebula Cluster. Since the observations cannot provide all the necessary information for our simulations, we make choices for the missing data and assess the impact of those choices. We find that the results are insensitive to the adopted choices of the gas velocity in the plane of the sky. The properties of the surrounding gas cloud (e.g. overall density and size), however, have an effect on the star formation rate and pace of assembly of the resultant star cluster. We also analyse the stellar properties of the cluster and find that the stars become more tightly clustered and in a stronger radial distribution even as new stars form in the filament.

Authors 6

1. Alison Sills corresponding

   McMaster University

   Affiliation as printed

   Department of Physics and Astronomy, McMaster University , 1280 Main Street West, Hamilton, ON L8S 4M1, Canada

2. Steven Rieder

   University of Geneva · University of Exeter

   Affiliation as printed

   Geneva Observatory, University of Geneva , Chemin Pegasi 51, CH-1290 Sauverny, Switzerland

   School of Physics and Astronomy, University of Exeter , Stocker Road, Exeter EX4 4QL, UK

3. Anne S. M. Buckner

   University of Exeter

   Affiliation as printed

   School of Physics and Astronomy, University of Exeter , Stocker Road, Exeter EX4 4QL, UK

4. A. Hacar

   University of Vienna

   Affiliation as printed

   Department of Astrophysics, University of Vienna , Türkenschanzstrasse 17, A-1180 Vienna, Austria

5. Simon Portegies Zwart Aachen Leiden Observatory

   Leiden University · Leiden Observatory

   Affiliation as printed

   Leiden Observatory, Leiden University , NL-2300RA Leiden, the Netherlands

6. Paula Stella Teixeira

   University of St Andrews

   Affiliation as printed

   SUPA, School of Physics and Astronomy, University of St. Andrews , North Haugh, St. Andrews, KY16 9SS Fife, UK