22 GIUGNO 2021 ore 15:00

Globular cluster pulsar science with the MeerKAT radio telescope

Dr. Alessandro Ridolfi (INAF-OAC, Italia)
Globular cluster pulsar science with the MeerKAT radio telescope

Globular clusters (GC) are spherical, self-gravitating collections of stars that orbit our Milky Way. Thanks to their extreme stellar densities, which favor frequent gravitational interactions between the stars, GCs are prolific factories for generating millisecond pulsars (MSPs): with 230 currently known pulsars, GCs account for about half of the total known MSP population. The high rate of interactions that is found in them also causes the typical stellar evolution paths to be significantly altered, resulting in the production of exotic binary systems and pulsars with unusual, and often extreme, properties. All of this makes GCs outstanding laboratories, and their pulsars can be exploited for a large variety of experiments: they can be used to test General Relativity, study binary evolution, probe the cluster's gravitational potential in search of non-luminous matter, detect possible intra-cluster ionized gas, study the Galactic magnetic field, and more.

The advent of the MeerKAT radio telescope, a precursor of the Square Kilometre Array (SKA), has recently given a major upturn in the science of pulsars in GCs. Being 6-8 times more sensitive than the Parkes radio telescope and up to 2 times more sensitive than the Green Bank Telescope, MeerKAT has been providing us with an entirely new view of the southern sky.

In this talk, I will report on the activities of the MeerKAT GC pulsar working group, in the context of the TRAPUM and MeerTIME experiments. After discussing about the observing strategy and the challenges that GC observations pose, I will review our major scientific results. Since the beginning of our observing programme, started in 2019, 39 new pulsars have been discovered in 11 different clusters. A few of these show interesting characteristics that are worthy of attention. Moreover, several of the previously known pulsars have been re-observed with MeerKAT, resulting in new studies made with unprecedented details. I will conclude discussing about the prospects of GC pulsar science with MeerKAT over the next few years, in view of the future expansions planned for the telescope, which is a core part of the newly born SKA Observatory.



Breve CV del Dr. Alessandro Ridolfi:

He did his studies in physics at the University of Rome "La Sapienza". For his Master's thesis work, he spent a few months at the Astronomical Observatory of Cagliari (OAC), during which he fell in love with pulsars and Sardinia. After graduating, he moved to Germany to work at the Max Planck Institute for Radioastronomy, where he obtained his PhD in 2017, with a thesis on pulsars in globular clusters. In October 2018 Alessandro came back to Cagliari, joining the OAC Pulsar Group as a post-doctoral researcher. Currently, he devotes most of his time to the search and timing of new pulsars in globular clusters using the MeerKAT radio telescope, within the TRAPUM and MeerTIME experiments.