SFXTs as best candidate counterparts of unidentified transient MeV-GeV sources: the test case of IGR J17354-3255/AGL J1734-3310

TL;DR

This paper explores the potential link between Supergiant Fast X-ray Transients (SFXTs) and unidentified transient MeV-GeV sources, proposing SFXTs as promising counterparts for these high-energy Galactic transients.

Contribution

It presents the case for SFXTs being the likely counterparts of unidentified transient MeV-GeV sources, focusing on the specific example of IGR J17354-3255 and AGL J1734-3310.

Findings

Possible physical association between IGR J17354-3255 and AGL J1734-3310.

SFXTs could be the counterparts of transient MeV-GeV sources.

Implications for understanding Galactic high-energy transient populations.

Abstract

In the last few years Fermi and AGILE observations have indicated the existence of a possible population of transient MeV-GeV sources located on the Galactic plane and characterized by fast flares lasting only a very few days. Notably, no blazar-like counterparts are known within their error boxes so they could represent a completely new class of Galactic transient high energy emitters. The task of identifying their counterparts at lower energies remains very challenging. Despite this difficulty, INTEGRAL observations have provided intriguing hints that reliable candidate counterparts for these unidentified MeV-GeV transients could be found among the members of the recently discovered class of Supergiant Fast X-ray Transients (SFXTs). In this context, to date the best test case is represented by the association between the two sources IGR J17354-3255 and AGL J1734-3310. We will discuss their possible physical link and implications stemming from this association.