Realistic assessment of a single gravitational wave source localization taking into account precise pulsar distances with pulsar timing arrays

2025/06/03 by Ryo Kato, Keitaro Takahashi, Kato, Ryo +1 · 4 citations
Earth and Planetary Sciences · Mathematics · Physics and Astronomy · #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geophysics and Gravity Measurements #High Energy Astrophysical Phenomena (astro-ph.HE) #Pulsars and Gravitational Waves Research #Statistical and numerical algorithms

paper · pdf · doi:10.48550/arxiv.2506.02819

openalex publication_date 2025/06/03 · openalex created_date 2025/10/14 · openalex updated_date 2026/07/31

Abstract

Pulsar timing arrays (PTAs) are anticipated to detect continuous gravitational waves (GWs) from individual supermassive black hole binaries (SMBHBs) in the near future. To identify the host galaxy of a GW source, PTAs require significantly improved angular resolution beyond the typical range of 100-1000 square degrees achieved by recent continuous GW searches. In this study, we investigate how precise pulsar distance measurements can enhance the localization of a single GW source. Accurate distance information, comparable to or better than the GW wavelength (typically 1~pc) can refine GW source localization. In the near future, with the advent of Square Kilometre Array (SKA), such high-precision distance measurements will be feasible for a few nearby pulsars. We focus on the relatively nearby pulsars J0437-4715 (156 pc) and J0030+0451 (331 pc), incorporating their actual distance uncertainties based on current VLBI measurements and the anticipated precision of the SKA-era. By simulating 87 pulsars with the GW signal and Gaussian white noise in the timing residuals, we assess the impact of the pulsar distance information on GW source localization. Our results show that without precise distance information, localization remains insufficient to identify host galaxies under 10 ns noise. However, incorporating SKA-era distance precision for nearby pulsars J0437-4715 and J0030+0451 can reduce localization uncertainties to the required level of 10^-3 \rm deg². Localization accuracy strongly depends on the geometric configuration of pulsars with well-measured distances and improves notably near and between such pulsars. The improvement of the localization will greatly aid in identifying the host galaxy of a GW source and constructing an SMBHB catalog. It will further enable follow-up electromagnetic observations to investigate the SMBHB in greater detail.

Citations

• Characterizing Continuous Gravitational Waves from Supermassive Black Hole Binaries in Realistic Pulsar Timing Array Data
• The MeerKAT Pulsar Timing Array: the first search for gravitational waves with the MeerKAT radio telescope
• State-space analysis of a continuous gravitational wave source with a pulsar timing array: inclusion of the pulsar terms
• Kalman tracking and parameter estimation of continuous gravitational waves with a pulsar timing array
• Rapid parameter estimation for pulsar-timing-array datasets with variational inference and normalizing flows
• Searching for the Nano-Hertz Stochastic Gravitational Wave Background with the Chinese Pulsar Timing Array Data Release I
• Results for the International Pulsar Timing Array Second Mock Data Challenge: New Techniques and Challenges for the Detection of Low-Frequency Gravitational-Wave Signals
• Null-stream pointing with pulsar timing arrays
• Detecting nanohertz gravitational waves with pulsar timing arrays
• Coherent network analysis for continuous gravitational wave signals in a pulsar timing array: Pulsar phases as extrinsic parameters
• Pulsar Timing Array Observations of Massive Black Hole Binaries

Cited by

• Two-Dimensional Pulsar Distance Inference from Nanohertz Gravitational Waves
• Reaching diffraction-limited localization with coherent PTAs
• The Dawn of Gravitational Wave Astronomy at Light-year Wavelengths: Insights from Pulsar Timing Arrays
• Expectations for the first supermassive black-hole binary resolved by PTAs II: Milestones for binary characterization

Related

• Two-Dimensional Pulsar Distance Inference from Nanohertz Gravitational Waves
• Sub-parsec precision measurement of pulsar distances with nanohertz gravitational waves
• The role of distant pulsars in the detectability of continuous gravitational waves
• Reaching diffraction-limited localization with coherent PTAs
• Pulsar Timing Array Observations of Massive Black Hole Binaries