Reducing the Impact of Weak-lensing Errors on Gravitational-wave Standard Sirens

Abstract

The mergers of supermassive black hole binaries (SMBHBs) can serve as standard sirens: the gravitational wave (GW) analog of standard candles. The upcoming space-borne GW detectors will be able to discover such systems and estimate their luminosity distances precisely. Unfortunately, weak gravitational lensing can induce significant errors in the measured distance of these standard sirens at high redshift, severely limiting their usefulness as precise distance probes. The uncertainty due to weak lensing can be reduced if the lensing magnification of the siren can be estimated independently, a procedure called 'delensing'. With the help of up-to-date numerical simulations, here we investigate how much the weak-lensing errors can be reduced using convergence maps reconstructed from shear measurements. We also evaluate the impact of delensing on cosmological parameter estimation with bright standard sirens. We find that the weak-lensing errors for sirens at $z_s=2.9$ can be reduced by about a factor of two on average, but to achieve this would require expensive ultra-deep field observations for every siren. Such an approach is likely to be practical in only limited cases, and the reduction in the weak-lensing error is therefore likely to be insufficient to significantly improve the cosmological parameter estimation. We conclude that performing delensing corrections is unlikely to be worthwhile, in contrast to the more positive expectations presented in previous studies. For delensing to become more practicable and useful in the future will require significant improvements in the resolution/depth of weak-lensing surveys and/or the methods to reconstruct convergence maps from these surveys.

20 pages, 22 figures, to be published in MNRAS

References in corpus (8)

• Laser Interferometer Space Antenna
• The evolution of massive black hole seeds
• The mass relations between supermassive black holes and their host galaxies at 1<z<2 with HST-WFC3
• Reducing the weak lensing noise for the gravitational wave Hubble diagram using the non-Gaussianity of the magnification distribution
• Probing Dark Low-mass Halos and Primordial Black Holes with Frequency-dependent Gravitational Lensing Dispersions of Gravitational Waves
• Simulations of Weak Gravitational Lensing - II : Including Finite Support Effects in Cosmic Shear Covariance Matrices
• Semi-analytic forecasts for JWST -- VI. Simulated lightcones and galaxy clustering predictions
• Post-Merger Jets from Supermassive Black Hole Coalescences as Electromagnetic Counterparts of Gravitational Wave Emission

Cited by in corpus (8)

• Weakly Lensed Gravitational Waves: Probing Cosmic Structures with Wave-Optics Features
• Probing wave-optics effects and low-mass dark matter halos with lensing of gravitational waves from massive black holes
• Wave effect of gravitational waves intersected with a microlens field II: an adaptive hierarchical tree algorithm and population study
• Fundamental Physics and Cosmology with TianQin
• Impact of weak lensing on bright standard siren analyses
• Is Dark Energy Changing? Probing the Universe's Expansion with present and future astronomical probes
• A deconstruction of methods to derive one-point lensing statistics
• High-Redshift Merger Model for Low-Frequency Gravitational Wave Background