The observable effects of tidally induced warps in protostellar discs

TL;DR

This paper studies how tidal forces induce warps in protostellar discs, affecting their structure and spectral energy distribution, especially at large radii and long wavelengths, with implications for disc observations.

Contribution

It introduces a wave-like model for warp communication in protostellar discs and analyzes its impact on the spectral energy distribution at large radii.

Findings

Warps are communicated in a wave-like manner in typical discs.

Warp effects are prominent beyond 30 AU and can last long with low viscosity.

Significant SED changes occur at wavelengths over 100 microns.

Abstract

We consider the response of a protostellar disc to a tidally induced warp and the resultant changes in the spectral energy distribution (SED). We argue that for typical protostellar disc parameters the warp is communicated through the disc in a wave-like fashion. We find that the main effects of the warp tend to be at large radii (greater than 30 AU) and, for sufficiently small viscosity, can be quite long-lived. This can result in non-uniform illumination of the disc at these radii and can induce significant changes to the SED at wavelengths greater than 100 microns.