Seminari
Thursday 05/05/2022 @ 11:30, JAC - Sala IV piano Battiferro (remote)
Franz Kirsten (ASTRON), "PRECISEly localising and timing FRBs -- hunting cosmic flashes with VLBI"
Fast radio bursts (FRB) are millisecond duration, extremely bright bursts of extragalactic origin. Despite a known population of ~1000 sources, we still do not know their progenitors, let alone the emission mechanism generating these flashes in the radio band. Most FRBs have only been seen once while some FRBs burst repeatedly, the so-called repeating FRBs. One key aspect needed to understand the nature of fast radio bursts (FRB) is their precise location. Simply knowing what type of host galaxies they are emitted from is not quite sufficient -- it is the local environment, e.g. star forming or not; association with a persistent counterpart or not -- that can give us insights on the type of objects that we can expect to emit FRBs. The astrometric precision required for such environmental studies is of order milliarcseconds, a resolution that can only be achieved with VLBI. In this talk I will discuss the latest results of our ad-hoc VLBI campaign called PRECISE. As of late, we doubled the number of repeating FRBs with a milliarcsecond-localisation. One of our targets, FRB20200120E, proved to be in a globluar cluster, challenging models that invoke a young magnetar formed via a core-collapse supernova as FRB progenitors. On the other hand, this source's bursts exhibit microstructure that is similar to what is seen in giant pulses from the Crab pulsar, tightening the link between extragalactic FRBs and young Galactic pulsars.