The MeerKAT Pulsar Timing Array: The 4.5-year data release and the noise and stochastic signals of the millisecond pulsar population

作     者：Miles, Matthew T. Shannon, Ryan M. Reardon, Daniel J. Bailes, Matthew Champion, David J. Geyer, Marisa Gitika, Pratyasha Grunthal, Kathrin Keith, Michael J. Kramer, Michael Kulkarni, Atharva D. Nathan, Rowina S. Parthasarathy, Aditya Porayko, Nataliya K. Singha, Jaikhomba Theureau, Gilles Abbate, Federico Buchner, Sarah Cameron, Andrew D. Camilo, Fernando Moreschi, Beatrice E. Shaifullah, Golam Shamohammadi, Mohsen Krishnan, Vivek Venkatraman 

作者机构：Centre for Astrophysics and Supercomputing Swinburne University of Technology PO Box 218 HawthornVIC3122 Australia OzGrav: The ARC Centre of Excellence for Gravitational Wave Discovery Australia MPI für Radioastronomie Auf dem Hügel 69 Bonn53121 Germany Group Department of Mathematics and Applied Mathematics University of Cape Town Cape Town7700 South Africa Jodrell Bank Centre for Astrophysics University of Manchester Alan-Turing Building Oxford Street ManchesterM13 9PL United Kingdom School of Physics and Astronomy Monash University ClaytonVIC3800 Australia ASTRON Netherlands Institute for Radio Astronomy Oude Hoogeveensedijk 4 Dwingeloo7991 PD Netherlands Anton Pannekoek Institute for Astronomy University of Amsterdam Science Park 904 Amsterdam1098 XH Netherlands Dipartimento di Fisica "G. Occhialini" Universitá degli Studi di Milano-Bicocca Piazza della Scienza 3 MilanoI-20126 Italy Laboratoire de Physique et Chimie de l’Environnement et de l’Espace LPC2E UMR7328 Université d’Orléans CNRS CNES OSUC Observatoire de Paris OrléansF-45071 France Laboratoire Univers et Théories Observatoire de Paris Université PSL Université de Paris Cité CNRS MeudonF-92190 France INAF – Osservatorio Astronomico di Cagliari Via della Scienza 5 CA SelargiusI-09047 Italy South African Radio Astronomy Observatory 2 Fir Street Black River Park Observatory7925 South Africa 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2024年

核心收录：

主　　题：Pulsars 

摘      要：Pulsar timing arrays are ensembles of regularly observed millisecond pulsars timed to high precision. Each pulsar in an array could be affected by a suite of noise processes, most of which are astrophysically motivated. Analysing them carefully can be used to understand these physical processes. However, the primary purpose of these experiments is to detect signals that are common to all pulsars, in particular signals associated with a stochastic gravitational wave background. To detect this, it is paramount to appropriately characterise other signals that may otherwise impact array sensitivity or cause a spurious detection. Here we describe the second data release and first detailed noise analysis of the pulsars in the MeerKAT Pulsar Timing Array, comprising high-cadence and high-precision observations of 83 millisecond pulsars over 4.5 years. We use this analysis to search for a common signal in the data, finding a process with an amplitude of log10 ACURN = (Formula Presented) and spectral index γCURN = (Formula Presented). Fixing the spectral index at the value predicted for a background produced by the inspiral of binary supermassive black holes, we measure the amplitude to be log10 ACURN = (Formula Presented) at a significance expressed as a Bayes factor of ln(B) = 4.46. Under both assumptions, the amplitude that we recover is larger than those reported by other PTA experiments. We use the results of this analysis to forecast our sensitivity to a gravitational wave background possessing the spectral properties of the common signal we have measured. Copyright © 2024, The Authors. All rights reserved.