Radio Transients Over a Wide Range of Timescales
Presentations
Overview
Overview
abstract
Burst phenomena, covering a wide range of timescales, are ubiquitous in astrophysics, ranging from less than a millisecond for Fast Radio Bursts (FRBs) to several years for some flares in maser sources. Understanding their origin and underlying physical processes is a significant goal of contemporary astrophysics. To this end, we have recently applied Dicke’s superradiance, a coherent quantum mechanical radiation mechanism, to the physics of the interstellar medium (ISM) to explain some of these burst phenomena. Although first discussed by R. H. Dicke in 1954 and studied in laboratories for several decades, superradiance remained unnoticed by astronomers until recently. In this presentation, I will first focus on so-called maser flares, present corresponding observational evidence for superradiance, and demonstrate how, under certain conditions, a region initially hosting a maser can transition to a superradiance regime. Additionally, investigations of superradiance within the context of FRBs have led us to develop a more general dynamical and relativistic model. This model not only reproduces some previously observed characteristics of repeating FRBs but, more importantly, predicts the existence of a relationship between the frequency drift in a single sub-burst and its temporal duration (the “sub-burst slope law”). I will present observational evidence that verifies this law for several sources associated with different types of host galaxies at various redshifts.
