A survey for radio pulsars and transients in the 10 pc region around Sgr A*

¹ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
² National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100101, PR China
³ INAF – Osservatorio Astronomico di Cagliari, Via della Scienza 5, 09047 Selargius (CA), Italy
⁴ Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, UK
⁵ State Key Laboratory of Radio Astronomy and Technology, Shanghai Astronomical Observatory, CAS, 80 Nandan Road, Shanghai 200030, PR China
⁶ Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, PR China
⁷ Instituto de Radioastronomía Milimetrica, Avda. Divina Pastora 7, Núcleo Central, 18012 Granada, Spain

^★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 11 July 2025
Accepted: 8 December 2025

Abstract

Here we report on a new survey for pulsars and transients in the 10 pc region around Sgr A^∗ using the Effelsberg radio telescope at frequencies between 4 and 8 GHz. Our calibrated full-Stokes data were searched for pulsars and transients using PULSARX, TRANSIENTX, and PRESTO. Polarisation information is used in the scoring of the candidates. Our periodicity acceleration and jerk searches allowed us to maintain good sensitivity towards binary pulsars in ≳10-h orbits. In addition, we performed a dedicated search in linear polarisation for slow transients. While our searches yielded no new discovery beyond the redetection of the magnetar SGR J1745−2900, we report on a faint single pulse candidate in addition to several weak periodicity search candidates. After thoroughly assessing our survey’s sensitivity, we determined that it is still not sensitive to a population of millisecond pulsars. Next generation radio interferometers can overcome the limitations of traditional single-dish pulsar searches of the Galactic Centre.