Eclipse Mapping: Astrotomography of Accretion Discs

TL;DR

The Eclipse Mapping Method is an indirect imaging technique used to create detailed maps of accretion disc brightness distributions in cataclysmic variables, revealing dynamic phenomena like waves, shocks, and disc precession.

Contribution

This paper reviews the principles, performance, limitations, and applications of the Eclipse Mapping Method in studying accretion discs around white dwarfs.

Findings

Revealed moving heating/cooling waves during outbursts

Detected tidally-induced spiral shocks with sub-Keplerian velocities

Mapped radial variation of disc viscosity and flickering sources

Abstract

The Eclipse Mapping Method is an indirect imaging technique that transforms the shape of the eclipse light curve into a map of the surface brightness distribution of the occulted regions. Three decades of application of this technique to the investigation of the structure, the spectrum and the time evolution of accretion discs around white dwarfs in cataclysmic variables have enriched our understanding of these accretion devices with a wealth of details such as (but not limited to) moving heating/cooling waves during outbursts in dwarf novae, tidally-induced spiral shocks of emitting gas with sub-Keplerian velocities, elliptical precessing discs associated to superhumps, and measurements of the radial run of the disc viscosity through the mapping of the disc flickering sources. This chapter reviews the principles of the method, discusses its performance, limitations, useful error propagation procedures, as well as highlights a selection of applications aimed at showing the possible scientific problems that have been and may be addresses with it.