FUSE Observational Evidence of the Boundary Layer of MY Lyrae in the High State

TL;DR

This study analyzes FUSE spectra of MV Lyrae in the high state, revealing that including a boundary layer in models improves flux fitting and provides insights into accretion rates, boundary layer temperature, and white dwarf heating.

Contribution

It introduces a spectral modeling approach that incorporates the boundary layer, improving flux fits and understanding of the system's physical parameters.

Findings

Boundary layer temperature around 100,000K

Moderate accretion rate of about 2.E09 solar masses/year

White dwarf possibly heated to 50,000K or higher

Abstract

We carry out a spectral analysis of the archival FUSE spectrum of the VY Scl nova-like cataclysmic variable MV Lyrae obtained in the high state. We find that standard disk models fail to fit the flux in the shorter wavelengths of FUSE (< 950$A). An improved fit is obtained by including a modeling of the boundary layer at the inner edge of the disk. The result of the modeling shows that in the high state the disk has a moderate accretion rate of about 2.E09 solar mass per year, a low inclination, a boundary layer with a temperature of around 100,000K, and size 0.20Rwd, and the white dwarf is possibly heated up to a temperature of 50,000K or higher.