Generalized Three-Cornered Hat Method and Its Application for the Construction of Pulsar Time Scale
Transactions of IAA RAS, issue 62, 21–28 (2022)
DOI: 10.32876/ApplAstron.62.21-28
Keywords: astronomical time scales, fractional instability, scale averaging methods, pulsars, gravitational-wave background, gravitational potential oscillations
About the paper Full textAbstract
The pulsar scale is long-term, uniform, reproducible and indestructible for all observers on Earth. Pulsars are located outside the Solar System, so they provide the only way to independently verify the scales of the Earth's atomic time, which is impossible when comparing only the Earth's clocks with each other. This, according to the authors of the article, is the main value of the pulsar time scale. The work is devoted to the method of selection of reference pulsars and the construction of a highly stable pulsar time scale independent of terrestrial conditions. Based on pulsar timing data from the NANOGrav (North American Nanohertz Observatory for Gravitational Waves) project, designed to search for a low-frequency gravitational-wave background, the task of rating and selecting reference pulsars and constructing an ensemble pulsar time scale was solved. Specifically for this purpose, a new method was developed, the so-called “generalized three cornered hat method”, combining two approaches: 1) pairwise comparison of the course of individual pulsar scales, 2) construction of group scales on different subsamples of three pulsars and comparison of the course of the obtained scales among themselves. The developed method makes it possible to identify pulsars with worse stability at long intervals. The course of the obtained group pulsar scale within the error range $\sigma_{\mathrm{ept}}=0.077$ microseconds coincides with the course of the TT (BIPM2017) scale. The fractional instability over the interval of 12 years is estimated at the level $\sigma_z=(1.0 \pm 0.9) \cdot 10^{-16}$. Based on the magnitude of fractional instability, an upper limit on the fractional energy density of the stochastic gravitational-wave background $\Omega_{\mathrm{g}} \mathrm{h}^2$ that arose in the early Universe at the level of $10^{-13}$ is obtained on the frequency $2.6 \times 10^{-10}$ Hz. The upper limit of the variations amplitude of the variable gravitational potential is estimated to be $\Psi_{\mathrm{c}} \sim 10^{-16}$ at the same frequency. The value of the fractional instability of the ensemble scale obtained in the paper is minimal at the time of writing the article. Its further improvement is associated with a drastic improvement in the accuracy of timing.
Citation
A. E. Rodin, V. A. Fedorova. Generalized Three-Cornered Hat Method and Its Application for the Construction of Pulsar Time Scale // Transactions of IAA RAS. — 2022. — Issue 62. — P. 21–28.
@article{rodin2022,
abstract = {The pulsar scale is long-term, uniform, reproducible and indestructible for all observers on Earth. Pulsars are located outside the Solar System, so they provide the only way to independently verify the scales of the Earth's atomic time, which is impossible when comparing only the Earth's clocks with each other. This, according to the authors of the article, is the main value of the pulsar time scale.
The work is devoted to the method of selection of reference pulsars and the construction of a highly stable pulsar time scale independent of terrestrial conditions. Based on pulsar timing data from the NANOGrav (North American Nanohertz Observatory for Gravitational Waves) project, designed to search for a low-frequency gravitational-wave background, the task of rating and selecting reference pulsars and constructing an ensemble pulsar time scale was solved. Specifically for this purpose, a new method was developed, the so-called “generalized three cornered hat method”, combining two approaches: 1) pairwise comparison of the course of individual pulsar scales, 2) construction of group scales on different subsamples of three pulsars and comparison of the course of the obtained scales among themselves. The developed method makes it possible to identify pulsars with worse stability at long intervals. The course of the obtained group pulsar scale within the error range $\sigma_{\mathrm{ept}}=0.077$ microseconds coincides with the course of the TT (BIPM2017) scale. The fractional instability over the interval of 12 years is estimated at the level $\sigma_z=(1.0 \pm 0.9) \cdot 10^{-16}$. Based on the magnitude of fractional instability, an upper limit on the fractional energy density of the stochastic gravitational-wave background $\Omega_{\mathrm{g}} \mathrm{h}^2$ that arose in the early Universe at the level of $10^{-13}$ is obtained on the frequency $2.6 \times 10^{-10}$ Hz. The upper limit of the variations amplitude of the variable gravitational potential is estimated to be $\Psi_{\mathrm{c}} \sim 10^{-16}$ at the same frequency. The value of the fractional instability of the ensemble scale obtained in the paper is minimal at the time of writing the article. Its further improvement is associated with a drastic improvement in the accuracy of timing.},
author = {A.~E. Rodin and V.~A. Fedorova},
doi = {10.32876/ApplAstron.62.21-28},
issue = {62},
journal = {Transactions of IAA RAS},
keyword = {astronomical time scales, fractional instability, scale averaging methods, pulsars, gravitational-wave background, gravitational potential oscillations},
pages = {21--28},
title = {Generalized Three-Cornered Hat Method and Its Application for the Construction of Pulsar Time Scale},
url = {http://iaaras.ru/en/library/paper/2132/},
year = {2022}
}
TY - JOUR
TI - Generalized Three-Cornered Hat Method and Its Application for the Construction of Pulsar Time Scale
AU - Rodin, A. E.
AU - Fedorova, V. A.
PY - 2022
T2 - Transactions of IAA RAS
IS - 62
SP - 21
AB - The pulsar scale is long-term, uniform, reproducible and
indestructible for all observers on Earth. Pulsars are located
outside the Solar System, so they provide the only way to
independently verify the scales of the Earth's atomic time, which is
impossible when comparing only the Earth's clocks with each other.
This, according to the authors of the article, is the main value of
the pulsar time scale. The work is devoted to the method of
selection of reference pulsars and the construction of a highly
stable pulsar time scale independent of terrestrial conditions. Based
on pulsar timing data from the NANOGrav (North American Nanohertz
Observatory for Gravitational Waves) project, designed to search for
a low-frequency gravitational-wave background, the task of rating and
selecting reference pulsars and constructing an ensemble pulsar time
scale was solved. Specifically for this purpose, a new method was
developed, the so-called “generalized three cornered hat method”,
combining two approaches: 1) pairwise comparison of the course of
individual pulsar scales, 2) construction of group scales on
different subsamples of three pulsars and comparison of the course of
the obtained scales among themselves. The developed method makes it
possible to identify pulsars with worse stability at long intervals.
The course of the obtained group pulsar scale within the error range
$\sigma_{\mathrm{ept}}=0.077$ microseconds coincides with the course
of the TT (BIPM2017) scale. The fractional instability over the
interval of 12 years is estimated at the level $\sigma_z=(1.0 \pm
0.9) \cdot 10^{-16}$. Based on the magnitude of fractional
instability, an upper limit on the fractional energy density of the
stochastic gravitational-wave background $\Omega_{\mathrm{g}}
\mathrm{h}^2$ that arose in the early Universe at the level of
$10^{-13}$ is obtained on the frequency $2.6 \times 10^{-10}$ Hz. The
upper limit of the variations amplitude of the variable gravitational
potential is estimated to be $\Psi_{\mathrm{c}} \sim 10^{-16}$ at the
same frequency. The value of the fractional instability of the
ensemble scale obtained in the paper is minimal at the time of
writing the article. Its further improvement is associated with a
drastic improvement in the accuracy of timing.
DO - 10.32876/ApplAstron.62.21-28
UR - http://iaaras.ru/en/library/paper/2132/
ER -