https://doi.org/10.1140/epjp/s13360-021-02098-0
Regular Article
Including millisecond pulsars inside the core of globular clusters in pulsar timing arrays
1
Department of Mathematics and Physics “Ennio De Giorgi”, University of Salento, Via per Arnesano, I-73100, Lecce, Italy
2
Istituto Nazionale di Fisica Nucleare INFN, Sezione di Lecce, Via per Arnesano, I-73100, Lecce, Italy
3
Istituto Nazionale di Astrofisica INAF, Sezione di Lecce, Via per Arnesano, I-73100, Lecce, Italy
Received:
31
August
2021
Accepted:
19
October
2021
Published online:
28
October
2021
We suggest the possibility of including millisecond pulsars inside the core of globular clusters in pulsar timing array experiments. Since they are very close to each other, their gravitational wave-induced timing residuals are expected to be almost the same, because both the Earth and the pulsar terms are correlated. We simulate the expected timing residuals, due to the gravitational wave signal emitted by a uniform supermassive black-hole binary population, on the millisecond pulsars inside a globular cluster core. In this respect, Terzan 5 has been adopted as a globular cluster prototype and, in our simulations, we adopted similar distance, core radius, and number of millisecond pulsars contained in it. Our results show that the presence of a strong correlation between the timing residuals of the globular cluster core millisecond pulsars can provide a remarkable gravitational wave signature. This result can be therefore exploited for the detection of gravitational waves through pulsar timing, especially in conjunction with the standard cross-correlation search carried out by the pulsar timing array collaborations.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021
