Can we see pulsars around Sgr A*? - The latest searches with the Effelsberg telescope

TL;DR

This paper reports on recent high-frequency radio searches for pulsars near Sgr A* using the Effelsberg telescope, aiming to overcome interstellar scattering that hampers pulsar detection in the Galactic center.

Contribution

It presents the latest search results at 18.95 GHz, exploring a new observational regime to detect pulsars close to Sgr A* and test gravitational physics.

Findings

No pulsars detected within the searched region.

High-frequency observations reduce scattering effects.

Provides constraints on pulsar population near Sgr A*.

Abstract

Radio pulsars in relativistic binary systems are unique tools to study the curved space-time around massive compact objects. The discovery of a pulsar closely orbiting the super-massive black hole at the centre of our Galaxy, Sgr A*, would provide a superb test-bed for gravitational physics. To date, the absence of any radio pulsar discoveries within a few arc minutes of Sgr A* has been explained by one principal factor: extreme scattering of radio waves caused by inhomogeneities in the ionized component of the interstellar medium in the central 100 pc around Sgr A*. Scattering, which causes temporal broadening of pulses, can only be mitigated by observing at higher frequencies. Here we describe recent searches of the Galactic centre region performed at a frequency of 18.95 GHz with the Effelsberg radio telescope.