Post-Newtonian-accurate pulsar timing array signals induced by inspiralling eccentric binaries: accuracy, computational cost, and single-pulsar search

Abstract

Pulsar Timing Array (PTA) experiments are expected to be sensitive to gravitational waves (GWs) emitted by individual supermassive black hole binaries (SMBHBs) inspiralling along eccentric orbits. We compare the computational cost of different methods of computing the PTA signals induced by relativistic eccentric SMBHBs, namely approximate analytic expressions, Fourier series expansion, post-circular expansion, and numerical integration. We show that the fastest method for evaluating PTA signals is by using the approximate analytic expressions, which provides up to ~50 times improvement in computational speed over the alternative methods. We investigate the accuracy of the approximate analytic expressions by employing a mismatch metric valid for PTA signals. We show that this method is accurate within the region of the binary parameter space that is of interest to PTA experiments. We introduce a spline-based method to further accelerate the PTA signal evaluations for narrowband PTA datasets. The efficient methods for computing the eccentric SMBHB-induced PTA signals were implemented in the GWecc.jl package and can be readily accessed from the popular ENTERPRISE package to search for such signals in PTA datasets. Further, we simplify the eccentric SMBHB PTA signal expression for the case of a single-pulsar search and demonstrate our computationally efficient methods by performing a single-pulsar search in the 12.5-year NANOGrav narrowband dataset of PSR J1909-3744 using the simplified expression. These results will be crucial for searching for eccentric SMBHBs in large PTA datasets.

Accepted for publication in Classical and Quantum Gravity

References in corpus (18)

• Array Programming with NumPy
• GWTC-2: Compact Binary Coalescences Observed by LIGO and Virgo During the First Half of the Third Observing Run
• The NANOGrav 12.5-year Data Set: Search For An Isotropic Stochastic Gravitational-Wave Background
• The International Pulsar Timing Array second data release: Search for an isotropic Gravitational Wave Background
• On the evidence for a common-spectrum process in the search for the nanohertz gravitational-wave background with the Parkes Pulsar Timing Array
• Common-red-signal analysis with 24-yr high-precision timing of the European Pulsar Timing Array: Inferences in the stochastic gravitational-wave background search
• The NANOGrav 12.5 yr Data Set: Observations and Narrowband Timing of 47 Millisecond Pulsars
• NANOGrav Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries in Circular Orbits
• The Parkes Pulsar Timing Array Project: Second data release
• Astrophysics Milestones For Pulsar Timing Array Gravitational Wave Detection
• The NANOGrav 12.5-year Data Set: Wideband Timing of 47 Millisecond Pulsars
• The MeerKAT Pulsar Timing Array: First Data Release
• The Indian Pulsar Timing Array: First data release
• Solving post-Newtonian accurate Kepler Equation
• Detection and localization of single-source gravitational waves with pulsar timing arrays
• Accurate characterization of the stochastic gravitational-wave background with pulsar timing arrays by likelihood reweighting
• Multimessenger pulsar timing array constraints on supermassive black hole binaries traced by periodic light curves
• Nanohertz Gravitational Wave Astronomy during the SKA Era: An InPTA perspective

Cited by in corpus (6)

• Status Report on Global Pulsar-Timing-Array Efforts to Detect Gravitational Waves
• The NANOGrav 12.5-year data set: A computationally efficient eccentric binary search pipeline and constraints on an eccentric supermassive binary candidate in 3C 66B
• Charting the Nanohertz Gravitational Wave Sky with Pulsar Timing Arrays
• Efficient Bayesian inference and model selection for continuous gravitational waves in pulsar timing array data
• Realistic assessment of a single gravitational wave source localization taking into account precise pulsar distances with pulsar timing arrays
• Efficient prescription to search for linear gravitational wave memory from hyperbolic black hole encounters and its application to the NANOGrav 12.5-year dataset