Title

EARTH, MOON, SUN, AND CV ACCRETION DISKS

Authors

Authors

M. M. Montgomery

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

Astrophys. J.

Keywords

accretion, accretion disks; binaries: close; binaries: general; methods:; analytical; novae, cataclysmic variables; stars: dwarf novae; X-RAY BINARIES; PARTICLE HYDRODYNAMICS SIMULATIONS; DRIVEN ECCENTRIC; INSTABILITIES; FAINT CATACLYSMIC VARIABLES; HIGH-SPEED PHOTOMETRY; AM; CANUM-VENATICORUM; SW SEXTANTIS STARS; DW URSAE MAJORIS; DWARF NOVA; V603 AQUILAE; Astronomy & Astrophysics

Abstract

Net tidal torque by the secondary on a misaligned accretion disk, like the net tidal torque by the Moon and the Sun on the equatorial bulge of the spinning and tilted Earth, is suggested by others to be a source to retrograde precession in non-magnetic, accreting cataclysmic variable (CV) dwarf novae (DN) systems that show negative superhumps in their light curves. We investigate this idea in this work. We generate a generic theoretical expression for retrograde precession in spinning disks that are misaligned with the orbital plane. Our generic theoretical expression matches that which describes the retrograde precession of Earths' equinoxes. By making appropriate assumptions, we reduce our generic theoretical expression to those generated by others, or to those used by others, to describe retrograde precession in protostellar, protoplanetary, X-ray binary, non-magnetic CV DN, quasar, and black hole systems. We find that spinning, tilted CV DN systems cannot be described by a precessing ring or by a precessing rigid disk. We find that differential rotation and effects on the disk by the accretion stream must be addressed. Our analysis indicates that the best description of a retrogradely precessing spinning, tilted, CV DN accretion disk is a differentially rotating, tilted disk with an attached rotating, tilted ring located near the innermost disk annuli. In agreement with the observations and numerical simulations by others, we find that our numerically simulated CV DN accretion disks retrogradely precess as a unit. Our final, reduced expression for retrograde precession agrees well with our numerical simulation results and with selective observational systems that seem to have main-sequence secondaries. Our results suggest that a major source to retrograde precession is tidal torques like that by the Moon and the Sun on the Earth. In addition, these tidal torques should be common to a variety of systems where one member is spinning and tilted, regardless if accretion disks are present or not. Our results suggest that the accretion disk's geometric shape directly affects the disk's precession rate.

Journal Title

Astrophysical Journal

Volume

705

Issue/Number

1

Publication Date

1-1-2009

Document Type

Review

Language

English

First Page

603

Last Page

616

WOS Identifier

WOS:000270903200049

ISSN

0004-637X

Share

COinS