Unified mapmaking for an anisotropic stochastic gravitational wave background

Abstract

A stochastic gravitational wave background (SGWB), created by the superposition of signals from unresolved astrophysical sources, may be detected in the next few years. Estimating the variation of intensity across the sky can, therefore, play a key role in improving our understanding of astrophysical models. Skymaps have been produced for all the data-taking runs of the advanced ground-based interferometric detectors. While these maps are being produced in pixel and SpH bases, to probe, respectively, localized and diffuse astrophysical and cosmological sources, with algorithms that employ cross-correlation as the common strategy, the underlying algebra and numerical implementation remain different. As a consequence, there was a need for producing skymaps in both bases in those analyses. We show that these manifestly redundant methods could indeed be unified to a single analysis that can probe very different scales and demonstrate it by applying them on real data. We first develop the algebra to show that the results in two different bases are easily transformable. We then incorporate both the schemes in the now-standard analysis pipeline for anisotropic SGWB, PyStoch. This will enable SGWB anisotropy searches in SpH basis also to take full advantage of integrated \hpx tools and makes it computationally feasible to perform the search in every frequency bin. We, however, follow a different approach for direct estimation of the SpH moments. We show that the results obtained from these different methods match very well; the differences are less than $0.1$\% for the SpH moments and less than $0.01$\% for the Fisher information matrices. Thus we conclude that a single skymap will be sufficient to describe the anisotropies in a stochastic background. The multiple capabilities of PyStoch will be useful for estimating and constraining various measures that characterize an anisotropic background.

arXiv comment10 pages, 9 figures

References in corpus (41)

• Observation of Gravitational Waves from a Binary Black Hole Merger
• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Advanced Virgo: a 2nd generation interferometric gravitational wave detector
• Laser Interferometer Space Antenna
• Interferometer design of the KAGRA gravitational wave detector
• Detecting a stochastic background of gravitational radiation: Signal processing strategies and sensitivities
• Detection methods for stochastic gravitational-wave backgrounds: a unified treatment
• The NANOGrav 11-year Data Set: Pulsar-timing Constraints On The Stochastic Gravitational-wave Background
• The Sensitivity of Ligo to a Stochastic Background, and its Dependance on the Detector Orientations
• GW170817: Implications for the Stochastic Gravitational-Wave Background from Compact Binary Coalescences
• Gravitational wave background from binary systems
• Stochastic Gravitational Wave Background from Coalescing Binary Black Holes
• Characterising gravitational wave stochastic background anisotropy with Pulsar Timing Arrays
• Detection of Anisotropies in the Gravitational-Wave Stochastic Background
• On the gravitational wave background from compact binary coalescences in the band of ground-based interferometers
• Directional limits on persistent gravitational waves from Advanced LIGO's first observing run
• Anisotropy of the astrophysical gravitational wave background: analytic expression of the angular power spectrum and correlation with cosmological observations
• Probing the anisotropies of a stochastic gravitational-wave background using a network of ground-based laser interferometers
• Accessibility of the Gravitational-Wave Background due to Binary Coalescences to Second and Third Generation Gravitational-Wave Detectors
• A radiometer for stochastic gravitational waves
• Anisotropies in the stochastic gravitational-wave background: Formalism and the cosmic string case
• Gravitational wave radiometry: Mapping a stochastic gravitational wave background
• Imprint of the merger and ring-down on the gravitational wave background from black hole binaries coalescence
• Anisotropies in the astrophysical gravitational-wave background: Predictions for the detection of compact binaries by LIGO and Virgo
• Directional limits on persistent gravitational waves using data from Advanced LIGO's first two observing runs
• Stochastic background of gravitational waves emitted by magnetars
• StarTrack predictions of the stochastic gravitational-wave background from compact binary mergers
• The $N_{\ell }$ of gravitational wave background experiments
• Gravitational wave background from rotating neutron stars
• Stochastic gravitational wave background from hydrodynamic turbulence in differentially rotating neutron stars
• Polarization of a stochastic gravitational wave background through diffusion by massive structures
• Improved limits on a stochastic gravitational-wave background and its anisotropies from Advanced LIGO O1 and O2 runs
• Very fast stochastic gravitational wave background map making using folded data
• Detecting a Stochastic Gravitational-Wave Background: The Overlap Reduction Function
• A synthetic model of the gravitational wave background from evolving binary compact objects
• Fast Gravitational Wave Radiometry using Data Folding
• Astrophysical motivation for directed searches for a stochastic gravitational wave background
• Multibaseline gravitational wave radiometry
• The cross-correlation search for a hot spot of gravitational waves
• Probing the Fermi-LAT GeV excess with gravitational waves
• Stochastic gravitational wave background mapmaking using regularised deconvolution

Cited by in corpus (11)

• Search for anisotropic gravitational-wave backgrounds using data from Advanced LIGO and Advanced Virgo's first three observing runs
• Stochastic gravitational wave background: methods and Implications
• All-sky, all-frequency directional search for persistent gravitational-waves from Advanced LIGO's and Advanced Virgo's first three observing runs
• Stochastic gravitational-wave background searches and constraints on neutron-star ellipticity
• Upper limits on persistent gravitational waves using folded data and the full covariance matrix from Advanced LIGO${}^{\prime }$s first two observing runs
• Measurement of the Cross-Correlation Angular Power Spectrum Between the Stochastic Gravitational Wave Background and Galaxy Over-Density
• Jointly setting upper limits on multiple components of an anisotropic stochastic gravitational-wave background
• Angular power spectra of anisotropic stochastic gravitational wave background: developing statistical methods and analyzing data from ground-based detectors
• Bayesian parameter estimation for targeted anisotropic gravitational-wave background
• Untargeted Bayesian search of anisotropic gravitational-wave backgrounds through the analytical marginalization of the posterior
• Unbiased estimation of gravitational-wave anisotropies from noisy data