Spectroscopic Binary Orbits in the Young Open Cluster M35

Type Conference Paper
Names Emily Leiner, R. D. Mathieu, A. M. Geller
Proceedings Title American Astronomical Society, AAS Meeting #223, #442.15
Conference Name American Astronomical Society Meeting Abstracts
Date January 1, 2014
URL http://adsabs.org/2014AAS.22344215L
Library Catalog labs.adsabs.harvard.edu
Abstract The young (150 Myr) open cluster M35 has been one of the core clusters of the WIYN Open Cluster Study (WOCS) since 1997. Over these 15 years we have obtained nearly 8000 radial-velocity (RV) measurements of stars in the M35 field. Our target sample consists of 1355 photometrically selected stars in the field of M35 within the main sequence and binary sequence of the cluster with 13 < V < 16.5 and (B-V) > 0.6. It also includes a few X-ray sources revealed in XMM-Newton observations. Using our RV measurements we have been able to adequately separate likely cluster members from field stars. We have RV membership probabilities for over 1200 stars in our sample, over 400 of which are probable cluster members. Our survey has also revealed 240 velocity-variable stars. Here we present more than 50 orbital solutions of variable cluster members. This sample defines the hard binary population of M35 that dynamically powers the cluster, and enables us to investigate important properties such as the period-eccentricity distribution, binary frequency, and the secondary mass distribution of M35. Understanding these properties in a young cluster is key to defining the initial conditions used in models of cluster dynamical evolution. Support for this program is provided by the National Science Foundation through grant AST-0908082.
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