WIYN Open Cluster Study. LXVI. Spectroscopic binary orbits in the young open cluster M35 (NGC 2168)

Journal Article · Wed Jul 01 04:00:00 EDT 2015 · The Astronomical Journal (Online)

DOI:https://doi.org/10.1088/0004-6256/150/1/10· OSTI ID:22879470

Leiner, E. M.; Mathieu, R. D. ^[1]; Gosnell, N. M. ^[2]

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1. Department of Astronomy, University of Wisconsin—Madison, WI 53706 (United States)
2. Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States)

The young (150 Myr) open cluster M35 (NGC 2168) has been one of the core clusters of the WIYN Open Cluster Study since 1997. Over these 17 years we have obtained approximately 8000 radial-velocity (RV) measurements of stars in the M35 field, which we provide here. Our target sample consists of 1355 photometrically selected stars in the field of M35 within the main sequence and binary sequence of the cluster and within 13⩽V⩽16.5 and (B−V)⩾0.6. Using our RV measurements we cleanly separate likely cluster members from field stars. We calculate RV membership probabilities for over 1200 stars in our sample. 418 are probable cluster members, of which 64 are velocity-variable (binary) systems. Here we present 52 orbital solutions for binary members of M35. This sample defines the hard binary population of M35 that dynamically powers the cluster. We also present XMM-Newton X-ray detections within the cluster. We use our large binary sample to search for interacting binaries among the X-ray sources, investigate M35's period–eccentricity distribution, and determine binary frequency. We find a circularization period of 9.9 ± 1.2 days and a binary frequency of 24% ± 3% for main-sequence binaries with P<10{sup 4} days. Determining these properties in a young cluster like M35 is key to defining the initial conditions used in models of cluster dynamical evolution.

• OSTI ID: 22879470
• Journal Information: The Astronomical Journal (Online), Journal Name: The Astronomical Journal (Online) Journal Issue: 1 Vol. 150; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BINARY STARS
MATHEMATICAL SOLUTIONS
ORBITS
PROBABILITY
RADIAL VELOCITY
SPECTROSCOPY
STAR CLUSTERS
X-RAY DETECTION
X-RAY SOURCES