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Title: TIDAL INTERACTIONS IN MERGING WHITE DWARF BINARIES

Abstract

The recently discovered system J0651 is the tightest known detached white dwarf (WD) binary. Since it has not yet initiated Roche-lobe overflow, it provides a relatively clean environment for testing our understanding of tidal interactions. I investigate the tidal heating of each WD, parameterized in terms of its tidal Q parameter. Assuming that the heating can be radiated efficiently, the current luminosities are consistent with Q {sub 1} {approx} 7 x 10{sup 10} and Q {sub 2} {approx} 2 x 10{sup 7}, for the He and C/O WDs, respectively. Conversely, if the observed luminosities are merely from the cooling of the WDs, these estimated values of Q represent the upper limits. A large Q {sub 1} for the He WD means its spin velocity will be slower than that expected if it was tidally locked, which, since the binary is eclipsing, may be measurable via the Rossiter-McLaughlin effect. After one year, gravitational wave emission shifts the time of eclipses by 5.5 s, but tidal interactions cause the orbit to shrink more rapidly, changing the time by up to an additional 0.3 s after a year. Future eclipse timing measurements may therefore infer the degree of tidal locking.

Authors:
 [1]
  1. Theoretical Astrophysics, California Institute of Technology, 1200 East California Boulevard, M/C 350-17, Pasadena, CA 91125 (United States)
Publication Date:
OSTI Identifier:
21565362
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 740; Journal Issue: 2; Other Information: DOI: 10.1088/2041-8205/740/2/L53; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ECLIPSE; EMISSION; GRAVITATIONAL WAVES; HEATING; INTERACTIONS; LUMINOSITY; WHITE DWARF STARS; DWARF STARS; OPTICAL PROPERTIES; PHYSICAL PROPERTIES; STARS

Citation Formats

Piro, Anthony L., E-mail: piro@caltech.edu. TIDAL INTERACTIONS IN MERGING WHITE DWARF BINARIES. United States: N. p., 2011. Web. doi:10.1088/2041-8205/740/2/L53.
Piro, Anthony L., E-mail: piro@caltech.edu. TIDAL INTERACTIONS IN MERGING WHITE DWARF BINARIES. United States. https://doi.org/10.1088/2041-8205/740/2/L53
Piro, Anthony L., E-mail: piro@caltech.edu. 2011. "TIDAL INTERACTIONS IN MERGING WHITE DWARF BINARIES". United States. https://doi.org/10.1088/2041-8205/740/2/L53.
@article{osti_21565362,
title = {TIDAL INTERACTIONS IN MERGING WHITE DWARF BINARIES},
author = {Piro, Anthony L., E-mail: piro@caltech.edu},
abstractNote = {The recently discovered system J0651 is the tightest known detached white dwarf (WD) binary. Since it has not yet initiated Roche-lobe overflow, it provides a relatively clean environment for testing our understanding of tidal interactions. I investigate the tidal heating of each WD, parameterized in terms of its tidal Q parameter. Assuming that the heating can be radiated efficiently, the current luminosities are consistent with Q {sub 1} {approx} 7 x 10{sup 10} and Q {sub 2} {approx} 2 x 10{sup 7}, for the He and C/O WDs, respectively. Conversely, if the observed luminosities are merely from the cooling of the WDs, these estimated values of Q represent the upper limits. A large Q {sub 1} for the He WD means its spin velocity will be slower than that expected if it was tidally locked, which, since the binary is eclipsing, may be measurable via the Rossiter-McLaughlin effect. After one year, gravitational wave emission shifts the time of eclipses by 5.5 s, but tidal interactions cause the orbit to shrink more rapidly, changing the time by up to an additional 0.3 s after a year. Future eclipse timing measurements may therefore infer the degree of tidal locking.},
doi = {10.1088/2041-8205/740/2/L53},
url = {https://www.osti.gov/biblio/21565362}, journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 740,
place = {United States},
year = {Thu Oct 20 00:00:00 EDT 2011},
month = {Thu Oct 20 00:00:00 EDT 2011}
}