THE LISA GRAVITATIONAL WAVE FOREGROUND: A STUDY OF DOUBLE WHITE DWARFS

Journal Article · Sat Jul 10 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/717/2/1006· OSTI ID:21455193

Ruiter, Ashley J ^[1]; Belczynski, Krzysztof ^[2]; Benacquista, Matthew; Williams, Gabriel ^[3]

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1. Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany)
2. Los Alamos National Laboratory, CCS-2/ISR-1 Group, P.O. Box 1663, Los Alamos, NM 87545 (United States)
3. Center for Gravitational Wave Astronomy, University of Texas at Brownsville, 80 Fort Brown, Brownsville, TX 78520 (United States)

Double white dwarfs (WDs) are expected to be a source of confusion-limited noise for the future gravitational wave observatory LISA. In a specific frequency range, this 'foreground noise' is predicted to rise above the instrumental noise and hinder the detection of other types of signals, e.g., gravitational waves arising from stellar-mass objects inspiraling into massive black holes. In many previous studies, only detached populations of compact object binaries have been considered in estimating the LISA gravitational wave foreground signal. Here, we investigate the influence of compact object detached and Roche-Lobe overflow (RLOF) Galactic binaries on the shape and strength of the LISA signal. Since >99% of remnant binaries that have orbital periods within the LISA sensitivity range are WD binaries, we consider only these binaries when calculating the LISA signal. We find that the contribution of RLOF binaries to the foreground noise is negligible at low frequencies, but becomes significant at higher frequencies, pushing the frequency at which the foreground noise drops below the instrumental noise to >6 mHz. We find that it is important to consider the population of mass-transferring binaries in order to obtain an accurate assessment of the foreground noise on the LISA data stream. However, we estimate that there still exists a sizeable number ({approx}11,300) of Galactic double WD binaries that will have a signal-to-noise ratio >5, and thus will be potentially resolvable with LISA. We present the LISA gravitational wave signal from the Galactic population of WD binaries, show the most important formation channels contributing to the LISA disk and bulge populations, and discuss the implications of these new findings.

• OSTI ID: 21455193
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 717; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BLACK HOLES
DIMENSIONLESS NUMBERS
DWARF STARS
EVOLUTION
GRAVITATION
GRAVITATIONAL WAVES
MASS TRANSFER
NOISE
POTENTIALS
ROCHE EQUIPOTENTIALS
SIGNAL-TO-NOISE RATIO
SIGNALS
STAR EVOLUTION
STARS
WHITE DWARF STARS