ADAFs, accretion discs and outbursts in compact binaries

TL;DR

This paper reviews the Soft X-ray Transient model, comparing ADAF-based accretion disc evaporation with observations, and questions the applicability of the Disc Instability Model to certain dwarf-novae due to recent distance measurements.

Contribution

It critically examines the ADAF model in the context of observed data and challenges the universality of the Disc Instability Model based on new distance estimates.

Findings

ADAF evaporation model compared with observations

Recent distance measurements challenge the Disc Instability Model for SS Cyg

Questions the applicability of the Disc Instability Model to dwarf-novae

Abstract

I discuss the status of the Soft X-ray Transient model. First, I discuss and then compare with observations the assumption that the geometrically thin disc evaporates into an ADAF. Second, I address the problems created by the recent determinations of the distance to SS Cyg, according to which the Disc Instability Model does not apply to this famous dwarf-nova, thus casting doubt on the application of this model to any system at all.