Review on latest progress on Supergiant Fast X-ray Transients and future direction

TL;DR

This review summarizes recent discoveries and understanding of Supergiant Fast X-ray Transients, highlighting their unique properties, challenges to existing theories, and future research directions with upcoming X-ray telescopes.

Contribution

It provides a comprehensive overview of observational properties and discusses the limitations of current models for Supergiant Fast X-ray Transients.

Findings

Supergiant Fast X-ray Transients exhibit rapid, bright X-ray flares.

Their properties challenge standard accretion theories.

Future telescopes will enhance understanding of these transients.

Abstract

In the recent years, the discovery of a new class of Galactic transients with fast and bright flaring X-ray activity, the Supergiant Fast X-ray Transients, has completely changed our view and comprehension of massive X-ray binaries. These objects display X-ray outbursts which are difficult to be explained in the framework of standard theories for the accretion of matter onto compact objects, and could represent a dominant population of X-ray binaries. I will review their main observational properties (neutron star magnetic field, orbital and spin period, long term behavior, duty cycle, quiescence and outburst emission), which pose serious problems to the main mechanisms recently proposed to explain their X-ray behavior. I will discuss both present results and future perspectives with the next generation of X-ray telescopes.