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arXiv · 2502.09275

Chinese Pulsar Timing Array upper limits on microhertz gravitational waves from supermassive black-hole binaries using PSR J1713+0747 FAST data

R. Nicolas Caballero·Heng Xu·Kejia Lee·Siyuan Chen·Yanjun Guo·Jinchen Jiang·Bojun Wan·Jiangwei Xu·Zihan Xue
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Abstract

We derive the gravitational-wave (GW) strain upper limits from resolvable supermassive black-hole binaries using the data from the Five-hundred-meter Aperture Spherical radio Telescope (FAST), in the context of the Chinese Pulsar Timing Array project. We focus on circular orbits in the $\mu$Hz GW frequency band between $10^{-7}$ and $3\times10^{-6}$ Hz. This frequency band is higher than the traditional pulsar timing array band and is less explored. We used the data of the millisecond pulsar PSR J1713+5307 observed between August 2019 and April 2021. A dense observation campaign was carried out in September 2020 to allow for the $\mu$Hz band coverage. Our sky-average continuous source upper limit at the 95% confidence level at 1$\mu$Hz is 1.26$\times10^{-12}$, while the same limit in the direction of the pulsar is 4.77$\times10^{-13}$.

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R. Nicolas Caballero, Heng Xu, Kejia Lee, Siyuan Chen, Yanjun Guo, Jinchen Jiang, Bojun Wan, Jiangwei Xu, Zihan Xue. 2025-02-13. Chinese Pulsar Timing Array upper limits on microhertz gravitational waves from supermassive black-hole binaries using PSR J1713+0747 FAST data. https://arxiv.org/abs/2502.09275

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