1. Multi-epoch searches for relativistic binary pulsars and fast transients in the Galactic Centre
- Author
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Kang Liu, Gregory Desvignes, Luciano Rezzolla, Michael Kramer, Heino Falcke, D. J. Champion, Kejia Lee, Laura Spitler, Bernd Klein, R. P. Eatough, Robert Wharton, Pablo Torne, Ramesh Karuppusamy, Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Astronomy ,Astrophysics::High Energy Astrophysical Phenomena ,Population ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Magnetar ,01 natural sciences ,Radio telescope ,stars: magnetars ,Pulsar ,Millisecond pulsar ,pulsars: general ,0103 physical sciences ,Spectroscopy and Catalysis ,education ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,education.field_of_study ,Supermassive black hole ,010308 nuclear & particles physics ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Galaxy: centre ,Neutron star ,Sagittarius A ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics - High Energy Astrophysical Phenomena ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
The high stellar density in the central parsecs around the Galactic Centre makes it a seemingly favourable environment for finding relativistic binary pulsars. These include pulsars orbiting other neutron stars, stellar-mass black holes or the central supermassive black hole, Sagittarius A*. Here we present multi-epoch pulsar searches of the Galactic Centre at four observing frequencies, (4.85, 8.35, 14.6 18.95) GHz, using the Effelsberg 100-m radio telescope. Observations were conducted one year prior to the discovery of, and during monitoring observations of, the Galactic Centre magnetar PSR J1745-2900. Our data analysis features acceleration searches on progressively shorter time series to maintain sensitivity to relativistic binary pulsars. The multi-epoch observations increase the likelihood of discovering transient or nulling pulsars, or ensure orbital phases are observed at which acceleration search methods work optimally. In ~147 h of separate observations, no previously undiscovered pulsars have been detected. Through calibration observations, we conclude this might be due to insufficient instantaneous sensitivity; caused by the intense continuum emission from the Galactic Centre, its large distance and, at higher frequencies, the aggregate effect of steep pulsar spectral indices and atmospheric contributions to the system temperature. Additionally we find that for millisecond pulsars in wide circular orbits ~, 17 pages, 12 figures, Accepted for publication in Monthly Notices of the Royal Astronomical Society
- Published
- 2021
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