Observational astrophysics

Observational astrophysics


Neutron stars, black holes and white dwarfs: compact objects are fascinating astronomical objects and laboratories of extreme physics.

Our research field is observational astrophysics with a main focus on compact objects in binary systems, neutron stars and accretion flows.

The astrophysics field of compact binary millisecond pulsars is thriving. This growing class of rapidly spinning neutron stars – also known as "spiders"– constitutes the most promising place to find massive pulsars. Super-massive neutron stars, with a mass significantly higher than two Solar masses, cannot contain exotic particles. Finding such stars would have profound implications for nuclear physics. The maximum neutron star mass has also important consequences for the fate of supernovae and the gravitational wave signal from neutron star mergers.

In addition, spiders offer a unique probe of the pulsar's innermost wind and a nearby site for particle acceleration. The past years have seen exciting discoveries in this field, in which our group has been closely involved. As a result, a new way has opened up to study fundamental astrophysical phenomena from compact binary millisecond pulsars.

We have been recently awarded an H2020 ERC Consolidator Grant: LOVE-NEST (PI: M. Linares). The purpose of this project is to find the most massive neutron stars and to understand the interaction between accretion flows, pulsar winds and neutron star magnetospheres. LOVE-NEST will first uncover a hidden population of millisecond pulsars, with a targeted search of gamma-ray candidate sources. We will then measure accurately the masses of the heaviest pulsars, using a novel technique that we have recently established. We will also investigate nearby spiders as potential sources of cosmic rays and astrophysical neutrinos, placing unprecedented constraints on particle acceleration in relativistic pulsar wind shocks.