Classical OBe Stars as Post-Supernova Runaways: Confirming Binary Origins

Abstract

Massive binaries play an important role in fields ranging from gravitational wave astronomy to stellar evolution. We provide several lines of evidence that classical OBe stars in the Small Magellanic Cloud (SMC) obtain their rapid rotation from mass and angular momentum transfer in massive binaries, which predicts that the subsequent supernovae should often eject OBe stars into the field. We find that (1) OBe stars have a higher field frequency than OB stars; (2) our cumulative distribution function (CDF) of stellar distances from O stars shows that OBe stars are indeed much more isolated than ordinary OB stars of corresponding spectral types; (3) the CDFs of OBe stars approach that of high-mass X-ray binaries (HMXBs), which are confirmed post-supernova objects; and (4) Oe stars are as isolated from clusters as Be stars, implying that their final masses are relatively independent of their initial masses, consistent with major mass transfer. Lastly, we also find that the spatial distribution of supergiant OBe stars differs from that of classical OBe stars, consistent with the different mechanism responsible for their emission-line spectra.

arXiv comment11 pages, 4 tables, 4 figures

References in corpus (39)

• Astropy: A Community Python Package for Astronomy
• How Massive Single Stars End their Life
• Binary interaction dominates the evolution of massive stars
• An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology
• Mass loss from hot massive stars
• Classical Be Stars: Rapidly Rotating B Stars with Viscous Keplerian Decretion Disks
• A UBVR CCD Survey of the Magellanic Clouds
• A spectroscopic survey on the multiplicity of high-mass stars
• Ten eclipsing binaries in the Small Magellanic Cloud: fundamental parameters and SMC distance
• Massive runaways and walkaway stars
• The VLT-FLAMES Survey of Massive Stars: Observations centered on the Magellanic Cloud clusters NGC 330, NGC 346, NGC 2004, and the N11 region
• Evolution towards the critical limit and the origin of Be stars
• Rotating Massive Main-Sequence Stars II: Simulating a Population of LMC early B-type Stars as a Test of Rotational Mixing
• Luminous Blue Variables are Antisocial: Their Isolation Implies that they are Kicked Mass Gainers in Binary Evolution
• Spitzer SAGE-SMC Infrared Photometry of Massive Stars in the Small Magellanic Cloud
• The origin of runaway stars
• On the formation of Be stars through binary interaction
• A 2dF survey of the Small Magellanic Cloud
• High-Mass X-ray binaries in the Small Magellanic Cloud
• Effects of metallicity, star-formation conditions, and evolution in B and Be stars. II: Small Magellanic Cloud, field of NGC 330
• On Be Star Candidates and Possible Blue Pre-Main Sequence Objects in the Small Magellanic Cloud
• The Detection and Characterization of Be+sdO Binaries from HST/STIS FUV Spectroscopy
• Be X-ray binaries in the SMC as indicators of mass transfer efficiency
• Investigating the lack of main-sequence companions to massive Be stars
• Massive Field Stars and the Stellar Clustering Law
• Prevalence of SED turndown among classical Be stars: Are all Be stars close binaries?
• The Runaways and Isolated O-Type Star Spectroscopic Survey of the SMC (RIOTS4)
• Be stars and binaries in the field of the SMC open cluster NGC330 with VLT-FLAMES
• On the kinematics of a runaway Be star population
• Two step ejection of massive stars and the issue of their formation in isolation
• The young massive SMC cluster NGC 330 seen by MUSE. I. Observations and stellar content
• A slitless spectroscopic survey for Halpha emission-line objects in SMC clusters
• Runaway OB Stars in the Small Magellanic Cloud: Dynamical Versus Supernova Ejections
• Shedding Light on the Isolation of Luminous Blue Variables
• A dearth of young and bright massive stars in the Small Magellanic Cloud
• The Initial Mass Function of Field OB Stars in the Small Magellanic Cloud
• Centrifugally Driven Mass Loss and Outbursts of Massive Stars
• Mapping the core of the Tarantula Nebula with VLT-MUSE II. The spectroscopic Hertzsprung-Russell diagram of OB stars in NGC 2070
• Clarifying the population of HMXBs in the Small Magellanic Cloud

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• A census of OBe stars in nearby metal-poor dwarf galaxies reveals a high fraction of extreme rotators
• Binarity at Low Metallicity (BLOeM) -- Multiplicity properties of Oe and Be stars
• Binarity at LOw Metallicity (BLOeM): Enhanced multiplicity of early B-type dwarfs and giants at $Z=0.2{\mathrm{Z}}_{\odot }$
• Populations of evolved massive binary stars in the Small Magellanic Cloud II: Predictions from rapid binary evolution
• High-spatial-resolution simulations of Be star disks in binary systems: I. Structure and kinematics of coplanar disks
• An observational study of rotation and binarity of Galactic O-type runaway stars
• New Field OB and OBe Binaries of the SMC Wing: Observational Properties and Population Modeling
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