Stochastic microhertz gravitational radiation from stellar convection

Abstract

High-Reynolds-number turbulence driven by stellar convection in main-sequence stars generates stochastic gravitational radiation. We calculate the wave-strain power spectral density as a function of the zero-age main-sequence mass for an individual star and for an isotropic, universal stellar population described by the Salpeter initial mass function and redshift-dependent Hopkins-Beacom star formation rate. The spectrum is a broken power law, which peaks near the turnover frequency of the largest turbulent eddies. The signal from the Sun dominates the universal background. For the Sun, the far-zone power spectral density peaks at $S(f_{\mathrm{peak}})=5.2\times 10^{-52}$ Hz${}^{-1}$ at frequency $f_{\mathrm{peak}}=2.3\times 10^{-7}$ Hz. However, at low observing frequencies $f<3\times 10^{-4}$ Hz, the Earth lies inside the Sun's near zone and the signal is amplified to $S_{\mathrm{near}}(f_{\mathrm{peak}})=4.1\times 10^{-27}$ Hz${}^{-1}$ because the wave strain scales more steeply with distance ($\propto d^{-5}$) in the near zone than in the far zone ($\propto d^{-1}$). Hence the Solar signal may prove relevant for pulsar timing arrays. Other individual sources and the universal background fall well below the projected sensitivities of the Laser Interferometer Space Antenna and next-generation pulsar timing arrays. Stellar convection sets a fundamental noise floor for more sensitive stochastic gravitational-wave experiments in the more distant future.

arXiv comment20 pages, 3 figures, accepted for publication in ApJ

References in corpus (33)

• On the normalisation of the cosmic star formation history
• BICEP2 I: Detection Of B-mode Polarization at Degree Angular Scales
• The Formation of the First Star in the Universe
• Physics, Astrophysics and Cosmology with Gravitational Waves
• Helioseismology
• Gravitational radiation from cosmic (super)strings: bursts, stochastic background, and observational windows
• The stochastic gravitational-wave background from massive black hole binary systems: implications for observations with Pulsar Timing Arrays
• An Upper Limit on the Stochastic Gravitational-Wave Background of Cosmological Origin
• Limits on the Stochastic Gravitational Wave Background from the North American Nanohertz Observatory for Gravitational Waves
• The Gravitational Wave Background from Cosmological Compact Binaries
• Gauge Field Production in Axion Inflation: Consequences for Monodromy, non-Gaussianity in the CMB, and Gravitational Waves at Interferometers
• Gravitational wave stochastic background from cosmic (super)strings
• Gravitational Radiation From Cosmological Turbulence
• Gravitational Waves from Electroweak Phase Transitions
• Placing limits on the stochastic gravitational-wave background using European Pulsar Timing Array data
• Short-period AM CVn systems as optical, X-ray and gravitational wave sources
• Gravitational Wave Production At The End Of Inflation
• Direct detection of the inflationary gravitational wave background
• The Spectrum of Gravitational Radiation from Primordial Turbulence
• Gravitational wave background from binary systems
• Gravitational Waves from Warped Spacetime
• Gravitational-wave Limits from Pulsar Timing Constrain Supermassive Black Hole Evolution
• Characterizing the Galactic Gravitational Wave Background with LISA
• Turbulent Convection in Stellar Interiors. II. The Velocity Field
• Stochastic background of gravitational waves generated by a cosmological population of young, rapidly rotating neutron stars
• Gravitational Wave Background from a Cosmological Population of Core-Collapse Supernovae
• Gravitational Wave Background from Magnetars
• Cosmic Background of Gravitational Waves from Rotating Neutron Stars
• Stochastic background of gravitational waves emitted by magnetars
• Stochastic gravitational wave background from hydrodynamic turbulence in differentially rotating neutron stars
• Gravitational Radiation from Hydrodynamic Turbulence in a Differentially Rotating Neutron Star
• Gravitational-wave bursts and stochastic background from superfluid vortex avalanches during pulsar glitches
• Response of a spaceborne gravitational wave antenna to solar oscillations

Cited by in corpus (4)

• The Astrophysics of Nanohertz Gravitational Waves
• Gravitational Waves from Neutron Stars: A Review
• Polarized Gravitational Waves from Cosmological Phase Transitions
• Extending the frequency reach of pulsar timing array based gravitational wave search without high cadence observations