On the Evidence for a Common-spectrum Process in the Search for the Nanohertz Gravitational-wave Background with the Parkes Pulsar Timing Array

doi:10.3847/2041-8213/ac17f4

	On the Evidence for a Common-spectrum Process in the Search for the Nanohertz Gravitational-wave Background with the Parkes Pulsar Timing Array
	Goncharov,Boris 1,2,3; Shannon,R. M.1,2; Reardon,D. J.1,2; Hobbs,G.4; Zic,A.4,5; Bailes,M.1,2; Cury?o,M.6; Dai,S.4,7; Kerr,M.8; Lower,M. E.1,4
刊名	The Astrophysical Journal Letters
	2021-08-01
卷号	917 期号:2
关键词	Gravitational waves Gravitational wave astronomy Millisecond pulsars Pulsar timing method Bayesian statistics
ISSN号	2041-8205
DOI	10.3847/2041-8213/ac17f4
通讯作者	Goncharov,Boris()
英文摘要	Abstract A nanohertz-frequency stochastic gravitational-wave background can potentially be detected through the precise timing of an array of millisecond pulsars. This background produces low-frequency noise in the pulse arrival times that would have a characteristic spectrum common to all pulsars and a well-defined spatial correlation. Recently the North American Nanohertz Observatory for Gravitational Waves collaboration (NANOGrav) found evidence for the common-spectrum component in their 12.5 yr data set. Here we report on a search for the background using the second data release of the Parkes Pulsar Timing Array. If we are forced to choose between the two NANOGrav models—one with a common-spectrum process and one without—we find strong support for the common-spectrum process. However, in this paper, we consider the possibility that the analysis suffers from model misspecification. In particular, we present simulated data sets that contain noise with distinctive spectra but show strong evidence for a common-spectrum process under the standard assumptions. The Parkes data show no significant evidence for, or against, the spatially correlated Hellings–Downs signature of the gravitational-wave background. Assuming we did observe the process underlying the spatially uncorrelated component of the background, we infer its amplitude to be A = 2.2 ? 0.3 + 0.4 × 10 ? 15 in units of gravitational-wave strain at a frequency of 1 yr?1. Extensions and combinations of existing and new data sets will improve the prospects of identifying spatial correlations that are necessary to claim a detection of the gravitational-wave background.
语种	英语
出版者	The American Astronomical Society
WOS记录号	IOP:2041-8205-917-2-AC17F4
内容类型	期刊论文
源URL	[http://ir.xao.ac.cn/handle/45760611-7/4231]
专题	新疆天文台_射电天文研究室
通讯作者	Goncharov,Boris
作者单位	1.Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122, Australia; boris.goncharov@me.com 2.OzGrav: The ARC Centre of Excellence for Gravitational Wave Discovery, Australia 3.Gran Sasso Science Institute (GSSI), I-67100 L’Aquila, Italy 4.Australia Telescope National Facility, CSIRO, Space and Astronomy, P.O. Box 76, Epping, NSW 1710, Australia 5.Department of Physics and Astronomy, and Research Centre in Astronomy, Astrophysics and Astrophotonics, Macquarie University, NSW 2109, Australia 6.Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw, Poland 7.Western Sydney University, Locked Bag 1797, Penrith South DC, NSW 1797, Australia 8.Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352, USA 9.School of Physics, University of Melbourne, Parkville, VIC 3010, Australia 10.Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany
推荐引用方式 GB/T 7714	Goncharov,Boris,Shannon,R. M.,Reardon,D. J.,et al. On the Evidence for a Common-spectrum Process in the Search for the Nanohertz Gravitational-wave Background with the Parkes Pulsar Timing Array[J]. The Astrophysical Journal Letters,2021,917(2).
APA	Goncharov,Boris.,Shannon,R. M..,Reardon,D. J..,Hobbs,G..,Zic,A..,...&Zhang,S..(2021).On the Evidence for a Common-spectrum Process in the Search for the Nanohertz Gravitational-wave Background with the Parkes Pulsar Timing Array.The Astrophysical Journal Letters,917(2).
MLA	Goncharov,Boris,et al."On the Evidence for a Common-spectrum Process in the Search for the Nanohertz Gravitational-wave Background with the Parkes Pulsar Timing Array".The Astrophysical Journal Letters 917.2(2021).