Studio di sistemi eclissanti di pulsar al millisecondo con dati del Sardinia Radio Telescope e Parkes Radio Telescope

Millisecond pulsars (MSPs) are a population of neutron stars (NSs) with fast spin (hundreds of rotations per second) and relatively weak magnetic field (10^8 Gauss). These objects are thought to be generated in low-mass X-ray binary systems (LMXBs), where a neutron star is spun up by the accretion of matter and angular momentum from its companion. This process is called “recycling” and the pulsars experiencing that are dubbed “recycled” pulsars. Among the MSPs, the so called “eclipsing binary millisecond pulsars” emit a radio signal which is distorted or completely disappears, at some particular orbital phases. There are two sub-populations of eclipsing MSPs: black widow (BW) and redback (RB) pulsars. Observations of these systems indicate the presence of a low-dense, highly ionized gas cloud enwrapping the companion, that causes a delay distorsion or even a complete absorption of the radio signal. Our work is oriented to the study of this kind of pulsar systems. Initially, we focused on the accurate study of one eclipsing MSP, called PSR J1431-4715, using radio observations from the Parkes 64 m telescope. We than performed a preliminary analysis of a set of data acquired during the early science program at the Sardinia Radio Telescope (SRT