Work

Tidal Novae in Compact Binary White Dwarfs

Year: 2012

Type: article

Abstract: Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in the inner stellar envelope and the dissipation of these waves in the outer envelope. As the binary orbit decays, the WDs are synchronized from outside in (with the envelope synchronized first, followed by the core). We examine the deposition of tidal heat in the envelope of a carbon–oxygen WD and study how such tidal heating affects the structure and evolution of the WD. We show that significant tidal heating can occur in the star's degenerate hydrogen layer. This layer heats up faster than it cools, triggering runaway nuclear fusion. Such "tidal novae" may occur in all WD binaries containing a CO WD, at orbital periods between 5 minutes and 20 minutes, and precede the final merger by 10 5 –10 6 years.

Source: The Astrophysical Journal Letters

DOI: 10.1088/2041-8205/756/1/l17

Authors: Jim Fuller, Dong Lai

Institution: Cornell University

Language: English

Topic: Stellar, planetary, and galactic studies

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funders: National Science Foundation, National Aeronautics and Space Administration, University of California, Santa Barbara

Awards: BUILDING UPON OUR RECENT WORK WE PROPOSE A THEORETICAL PROGRAM WITH THE GOAL OF USING GAMMA-RAY OBSERVATIONS TO CONSTRAIN/RECONSTRUCT THE STRUCTURE, THIS PROPOSAL FOCUSES ON UNDERSTANDING THE VARIOUS OBSERVATIONAL MANIFESTATIONS OF MAGNETIZED NEUTRON STARS (NSS), INCLUDING PULSARS, RADIO-QUIET THE, Matter and Radiation in Superstrong Magnetic Fields