The anomalous accretion disk of the Cataclysmic Variable RW Sextantis

TL;DR

This study models the spectrum of RW Sextantis, revealing an anomalous accretion disk structure inconsistent with standard models, and suggests a non-axisymmetric wind caused by stream debris interaction.

Contribution

It introduces a revised temperature profile exponent for the accretion disk and proposes an alternative explanation for observed wind features, challenging standard disk models.

Findings

A better spectral fit with a radial temperature exponent near 0.125.

Evidence against a warped or tilted disk from time-series spectra.

Identification of a non-axisymmetric wind caused by stream debris interaction.

Abstract

Synthetic spectra covering the wavelength range 900\AA~to 3000\AA~provide an accurate fit, established by a ${\chi}_{\nu}^2$ analysis, to a combined observed spectrum of RW Sextantis. Two separately calibrated distances to the system establish the synthetic spectrum comparison on an absolute flux basis but with two alternative scaling factors, requiring alternative values of $\dot{M}$ for final models. Based on comparisons for a range of $\dot{M}$ values, the observed spectrum does not follow the standard model. Rather than the exponent 0.25 in the expression for the radial temperature profile, a value close to 0.125 produces a synthetic spectrum with an accurate fit to the combined spectrum. A study of time-series $FUSE$ spectra shows that a proposed warped or tilted disk is not supported by the data; an alternative proposal is that an observed non-axisymmetric wind results from an interaction with the mass transfer stream debris.