Pulsar timing array source ensembles

verfasst von: Bruce Allen, Serena Valtolina
Abstract: The stochastic gravitational wave background for pulsar timing arrays is often modeled by a Gaussian ensemble which is isotropic and unpolarized. However, the Universe has a discrete set of polarized gravitational wave sources at specific sky locations. Can we trust that the Gaussian ensemble is an accurate description To investigate this, we explicitly construct an ensemble containing N individual binary sources with circular orbits. The orbital inclination angles are randomly distributed, hence the individual sources are elliptically polarized. We then compute the first two moments of the Hellings and Downs correlation, as well as the pulsar-averaged correlation mean and (cosmic) variance. The first moments are the same as for a previously studied ensemble of circularly polarized sources. However, the second moments, and hence the variances, are different for the two ensembles. While neither discrete source model is exactly described by a Gaussian ensemble, we show that in the limit of large N, the differences are small.
Organisationseinheit(en): Institut für Gravitationsphysik
Externe Organisation(en): Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut)
Typ: Artikel
Journal: Physical Review D
Band: 109
Anzahl der Seiten: 17
ISSN: 2470-0010
Publikationsdatum: 30.04.2024
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Kern- und Hochenergiephysik
Elektronische Version(en): https://doi.org/10.1103/PhysRevD.109.083038 (Zugang: Offen)

BibTeX

@article{635791fca54346a7bbab9202c37bec32,
title = "Pulsar timing array source ensembles",
abstract = "The stochastic gravitational wave background for pulsar timing arrays is often modeled by a Gaussian ensemble which is isotropic and unpolarized. However, the Universe has a discrete set of polarized gravitational wave sources at specific sky locations. Can we trust that the Gaussian ensemble is an accurate description To investigate this, we explicitly construct an ensemble containing N individual binary sources with circular orbits. The orbital inclination angles are randomly distributed, hence the individual sources are elliptically polarized. We then compute the first two moments of the Hellings and Downs correlation, as well as the pulsar-averaged correlation mean and (cosmic) variance. The first moments are the same as for a previously studied ensemble of circularly polarized sources. However, the second moments, and hence the variances, are different for the two ensembles. While neither discrete source model is exactly described by a Gaussian ensemble, we show that in the limit of large N, the differences are small.",
author = "Bruce Allen and Serena Valtolina",
note = "Publisher Copyright: {\textcopyright} 2024 authors. Published by the American Physical Society. ",
year = "2024",
month = apr,
day = "30",
doi = "10.1103/PhysRevD.109.083038",
language = "English",
volume = "109",
journal = "Physical Review D",
issn = "2470-0010",
publisher = "American Institute of Physics",
number = "8",
}