Circumbinary disk inner radius as a diagnostic for disk--binary misalignment

Abstract

We investigate the misalignment of the circumbinary disk around the binary HD 98800 BaBb with eccentricity $e\simeq 0.8$. \cite{Kennedy2019} observed the disk to be either at an inclination of $48^{\circ }$ or polar aligned to the binary orbital plane. Their simulations showed that alignment from $48^{\circ }$ to a polar configuration can take place on a shorter timescale than the age of this system. We perform hydrodynamical numerical simulations in order to estimate the cavity size carved by the eccentric binary for different disk inclinations as an independent check of polar alignment. Resonance theory suggests that torques on the inner parts of a polar disk around such a highly eccentric binary are much weaker than in the coplanar case, indicating a significantly smaller central cavity than in the coplanar case. We show that the inferred inner radius (from carbon monoxide measurements) of the accretion disk around BaBb can exclude the possibility of it being mildly inclined with respect to the binary orbital plane and therefore confirm the polar configuration. This study constitutes an important diagnostic for misaligned circumbinary disks, since it potentially allows us to infer the disk inclination from observed gas disk inner radii.

Accepted for publication in ApJL

References in corpus (17)

• Theory of Star Formation
• SPLASH: An interactive visualisation tool for Smoothed Particle Hydrodynamics simulations
• Smoothed Particle Hydrodynamics and Magnetohydrodynamics
• On the diversity and statistical properties of protostellar discs
• Warp diffusion in accretion discs: a numerical investigation
• Misaligned Disks in the Binary Protostar IRS 43
• Misaligned gas discs around eccentric black-hole binaries and implications for the final-parsec problem
• Polar alignment of a protoplanetary disk around an eccentric binary
• A circumbinary protoplanetary disc in a polar configuration
• Inclination Evolution of Protoplanetary Disks Around Eccentric Binaries
• Tidal Torques on Misaligned Disks in Binary Systems
• Linear Analysis of the Evolution of Nearly Polar Low Mass Circumbinary Discs
• Evolution of linear warps in accretion discs and applications to protoplanetary discs in binaries
• Alignment of a circumbinary disc around an eccentric binary with application to KH 15D
• Resonances in retrograde circumbinary discs
• Misaligned accretion disc formation via Kozai-Lidov oscillations
• HD 98800: A most unusual debris disc

Cited by in corpus (21)

• Orbital dynamics of circumbinary planets
• Polar alignment of a protoplanetary disc around an eccentric binary III: Effect of disc mass
• Polar planets around highly eccentric binaries are the most stable
• Formation of the polar debris disc around 99 Herculis
• Circumbinary discs for stellar population models
• GW Ori: circumtriple rings and planets
• A coplanar circumbinary protoplanetary disk in the TWA 3 triple M dwarf system
• Long live the disk: lifetimes of protoplanetary disks in hierarchical triple star systems and a possible explanation for HD 98800 B
• Formation of polar terrestrial circumbinary planets
• The eclipse of the V773 Tau B circumbinary disk
• Circumbinary disk evolution in the presence of an outer companion star
• The dipper population of Taurus seen with K2
• Constraining the Circumbinary Disk Tilt in the KH 15D system
• Terrestrial planet formation in a circumbinary disc around a coplanar binary
• Polar circumtriple planets and disks can only form close to a triple star
• Accretion onto a binary from a polar circumbinary disc
• Formation of polar circumstellar discs in binary star systems
• Tidal truncation of circumplanetary disks fails above a critical disk aspect ratio
• On the Nature of the T Tauri Triple System
• Excitation of post-AGB Star Binary Eccentricity by Massive Polar-Aligned Circumbinary Disks
• Brightness variability in polar circumbinary disks