# Observability of characteristic binary-induced structures in circumbinary disks

## TL;DR

This study uses hydrodynamic simulations and radiative transfer modeling to identify observable structures in circumbinary disks caused by binary interactions, assessing their detectability with ALMA and E-ELT.

## Contribution

It provides the first detailed analysis of characteristic binary-induced structures in circumbinary disks and evaluates their observability with current advanced telescopes.

## Key findings

- ALMA and E-ELT can detect asymmetries caused by binary interactions.
- Submillimetre/millimetre observations reveal density waves at the disk's inner rim.
- Infrared observations can resolve the innermost disk features including the rim and accretion arms.

## Abstract

Context: A substantial fraction of protoplanetary disks forms around stellar binaries. The binary system generates a time-dependent non-axisymmetric gravitational potential, inducing strong tidal forces on the circumbinary disk. This leads to a change in basic physical properties of the circumbinary disk, which should in turn result in unique structures that are potentially observable with the current generation of instruments. Aims: The goal of this study is to identify these characteristic structures, to constrain the physical conditions that cause them, and to evaluate the feasibility to observe them in circumbinary disks. Methods: To achieve this, at first two-dimensional hydrodynamic simulations are performed. The resulting density distributions are post-processed with a 3D radiative transfer code to generate re-emission and scattered light maps. Based on these, we study the influence of various parameters, such as the mass of the stellar components, the mass of the disk and the binary separation on observable features in circumbinary disks. Results: We find that the Atacama Large (sub-)Millimetre Array (ALMA) as well as the European Extremely Large Telescope (E-ELT) are capable of tracing asymmetries in the inner region of circumbinary disks which are affected most by the binary-disk interaction. Observations at submillimetre/millimetre wavelengths will allow the detection of the density waves at the inner rim of the disk and the inner cavity. With the E-ELT one can partially resolve the innermost parts of the disk in the infrared wavelength range, including the disk's rim, accretion arms and potentially the expected circumstellar disks around each of the binary components.