Does an Average White Dwarf Have Enough Mass to Prevent an Accretion Disk Tilt?

TL;DR

This paper investigates whether average white dwarf masses are sufficient to prevent accretion disk tilts in non-magnetic cataclysmic variables, finding that they generally do not, especially in low mass transfer systems.

Contribution

It provides a theoretical analysis showing that typical white dwarf masses are insufficient to prevent disk tilt, highlighting conditions under which tilts are likely.

Findings

Average white dwarf mass cannot prevent disk tilt.

Disk tilt is more likely in low mass transfer rate systems.

Secondary mass has minimal impact on disk tilt.

Abstract

In a recent publication, we introduce the lift force as a common source to accretion disk tilt that is likely relevant to accretion disk systems. Lift is generated by slightly different supersonic gas stream speeds flowing over and under the disk at the bright spot. In this conference proceeding, we focus on whether the average white dwarf has enough mass to prevent a disk tilt in non-magnetic Cataclysmic Variables (CVs) with accretion disks. Assuming a white dwarf mass of 0.6M$_{\odot}$ and a disk mass of 10$^{-11}$M$_{\odot}$, we vary the secondary mass to establish theoretical minimum mass transfer rates needed to induce and maintain a disk tilt of four degrees around the line of nodes. For mass ratios in the range \( (0.13 \le q=M_{2}M^{-1} \le 0.45) \), we confirm that the secondary mass does not contribute significantly to disk tilt. We also confirm that the average white dwarf does not have enough mass to prevent a disk tilt. We find that disk tilt may be likely in low mass transfer rate systems such as CV SU UMa's.