Conveners
Astrofisica Relativistica e Particellare
- Lucio Angelo Antonelli (Istituto Nazionale di Astrofisica (INAF))
Astrofisica Relativistica e Particellare
- Marica Branchesi (Istituto Nazionale di Astrofisica (INAF))
INAF researchers in the field of the Relativistic Astrophysics and Particles are members of the scientific national group 4 (Raggruppamento Scientifico Nazionale 4, RSN4).
The research activities of RNS4 fall in the observational, theoretical and experimental areas.
Observations are performed both with ground-based and space-based telescopes, maily in the high energy domain.
However, in...
The Imaging X-ray Polarimetry Explorer (IXPE), a NASA-ASI discovery Small Explorer mission (SMEX), was launched on December 9, 2021, thanks to the efforts of determined X-ray astronomers and engineers aiming to revolutionize our understanding of celestial sources. This achievement was made possible by an instrument conceived, built, and calibrated in Italy by INAF and INFN, with the industrial...
The high-energy (TeV-PeV) diffuse emission from our Galactic Plane has been recently measured both in gamma-ray and in neutrinos from several detectors. In this talk I will review the information that can be derived exploiting these observations and the different open questions raised by the comparison of theoretical expectations and the experimental data. In particular, the interaction of...
Dual Active Galactic Nuclei (DAGN, projected spatial separation rp < 100 kpc) are sources of great interest in astrophysics, since they are crucial to understand how AGN are triggered. However, DAGN are rare, and identify and characterize such sources is challenging and multi-waveband observations and analysis are needed. At early stage of separation (rp ∼ 30 − 100 kpc), we can exploit X-ray...
The huge luminosity, the redshift distribution extending at least up to z~10 and the association with the explosive death of very massive stars make long GRBs extremely powerful probes for investigating the early Universe (pop-III stars, cosmic re-ionization, SFR and metallicity evolution up to the “cosmic dawn”) and measuring cosmological parameters. At the same time, as demonstrated by the...
Very high energy astrophysics has got a boost in the recent years driven by the development of new observational facilities such as LHAASO, which started observing in the last few years, and CTAO and ASTRI-MiniArray, which are under construction. A key question that these instruments plan to address is the identification of hadronic PeVatrons, namely the most powerful particle accelerators in...
Gamma-ray burst spectra are absorbed by a significant amount of gas within their host galaxy. We can estimate the amount of this gas through broadband spectroscopy. X-ray spectra provide the most complete estimate of the amount of gas as they probe the total amount of material along the line of sight compared to optical spectra, which can only probe the relatively neutral gas and miss dust...
In August 2017, the groundbreaking observation of GW170817 marked the first-ever identification of a binary neutron star merger, accompanied by the detection of a Gravitational Wave (GW) and a gamma-ray burst (GRB). The GRB exhibited prompt gamma-ray emission and an afterglow across radio, optical, and X-ray bands, originating from a relativistic jet formed post-merger at an angle of 20-30...
Neutron stars are the compact remnants of massive stars that produce an energetic explosion we observe as a core-collapse supernova. The majority of massive stars are known to have been born in binary or multiple systems. When one of the stars in the system explodes, the orbital parameters can be significantly altered due to sudden mass loss and a natal kick; the binary can survive with a...
Galaxy mergers are thought to play a significant role in triggering accretion onto the central super massive black holes (SMBHs), resulting in Dual/Offset AGN. These systems are crucial probes of the accretion history of the universe, but are challenging to detect and characterize, therefore a detailed understanding remains unclear. The X-ray study of optically selected dual-AGN candidates...
The Eddington ratio λ_Edd is the key parameter that describes the accretion mode of active galactic nuclei (AGN). Among the different modes, high-λ_Edd accretion is particularly fascinating because of its implications in the context of accretion physics, as well as AGN feedback. However, due to their relative paucity in the local Universe (z<0.1), only few dedicated observations of AGN...
Galaxy clusters abundance as a function of mass and redshift is a powerful tool to constrain cosmological parameters, such as Ωm and σ8. However, their mass can be estimated for instance under the assumption that the gas filling the volume of the cluster, i.e. the Intra-Cluster Medium, is in hydrostatic equilibrium with the total matter content of the cluster, which consists mainly of dark...
