Astrophysique à Haute Energie

High-energy neutrino and γ-ray emission are expected from the Galactic plane, produced by interactions between cosmic rays and the interstellar medium or radiation fields. Recent LHAASO observations have detected diffuse γ-rays from the Galactic plane and an ultrahigh-energy γ-ray bubble (Cygnus Bubble) up to PeV energies, suggesting the possibility of neutrino emission. Using 7 years of publicly available IceCube track data with the full detector, we conducted searches for neutrino signals correlated with LHAASO diffuse Galactic γ-ray emission and Cygnus Bubble using a template method.

Evidence for a strong connection between the X-ray corona and the radio jet in black hole X-ray binaries has grown significantly. During state transitions, the inferred corona size correlates with both the jet’s flux and its synchrotron spectrum properties, offering insights into jet acceleration mechanisms. We investigate the properties of the Comptonizing medium in Swift J1727.8-1613 using the time-dependent Comptonization model vkompth, with NICER observations of type-C QPOs in the hard and hard-intermediate states.
In recent years, multiple lines of evidence have emerged supporting the idea that Be stars are mass gainers in interacting binaries. Together, these findings suggest a compelling scenario in which all Be stars are formed through binary interactions. Nevertheless, the broader implications of this scenario must be carefully examined within the context of massive binary evolution.

A l'occasion du lancement de la mission franco-chinoise SVOM (Space-based multi-band astronomical Variable Objects Monitor), prévu le 22 juin 2024, l'APC à le plaisir de vous convier à une matinée dédiée à ce projet consacré à l’étude des plus lointaines explosions d’étoiles, les sursauts gamma.


Titre/ Title:  Gamma Ray Bursts: what makes them shine?
Orateur/Speaker: Giancarlo Ghirlanda (INAF)
Lieu / Location:  
En ligne, les info de connexion zoom seront envoyées dans un e-mail séparé / online, zoom connection details will be sent in a separate email)