Conveners
Day 2: Latest results
- Massimo Dotti (Istituto Nazionale di Fisica Nucleare)
Day 2: Latest results
- Massimo Dotti (Istituto Nazionale di Fisica Nucleare)
Day 2: Latest results
- Sara Cutini (Istituto Nazionale di Fisica Nucleare)
Day 2: Latest results
- Serena Loporchio (INFN Bari)
I will present a summary of observations of active galaxies from the Imaging X-ray Polarimetry Explorer (IXPE). For radio quiet AGN such as NGC 1068 and the Circinus Galaxy, X-ray polarization results from scattering from the corona above the disk or from the inner wall of a molecular torus. Blazars whose synchrotron spectra peak at high frequencies (in or near the X-ray band), denoted as...
Polarimetry is a very important probe of the high-energy processes in the Universe. In December 2021 NASA launched the Imaging X-ray Polarimetry Explorer - IXPE, offering us a completely new window to the Universe, and the tools to study astrophysical systems from a radically different perspective. I will discuss the lessons learned from IXPE's two-year nominal mission and the implications for...
X-ray Quasi-Periodic Eruptions (QPEs) are high-amplitude bursts of X-ray radiation recurring every few hours and originating near the central black holes in galactic nuclei of low-mass galaxies. So far, only a handful of such events has been found. Some of the latest models suggest that these eruptions are triggered by extreme mass ratio inspirals (EMRIs), in which the secondary body interacts...
The radiation produced by the accretion of matter onto supermassive black holes exhibits stochastic flux variations across a range of timescales. These fluctuations offer critical insights into the geometry and physical conditions of the accretion flow as well as the interplay between the different energy emitting regions. In this presentation I will focus on the X-ray flux variability of AGN...
On April 10th, 2024 the second part of the fourth observing run (O4b) started with the detectors Advanced LIGO and Advanced Virgo resuming data taking. The run is ongoing and it is currently planned to end in June 2025.
In this talk, I will highlight the series of installed upgrades on Advanced Virgo plus since the end of the O3 observing run in view of O4. Moreover, I will focus on what...
The fourth observing run (O4) of LIGO-Virgo-KAGRA is ongoing, relying on the most sensitive network of gravitational-wave interferometers to date. In this talk, I will highlight some of the most recent astrophysical findings and their implications (in a multi-messenger context) for massive-star evolution, supernova theory, compact binary populations, and electromagnetic and cosmic-ray...
Black hole mergers, involving masses of tens to hundreds of solar masses, are believed to frequently occur within the accretion disks of central supermassive black holes, potentially producing observable electromagnetic counterparts. These counterparts understood as short flares, can last several days to weeks. Here, we present our initial results on the theoretical modelling of light curves...
Intermediate synchrotron-peaked BL Lacs (IBLs) are quite rare sources in the TeV gamma-ray sky. The IBL B2 1811+31 (z = 0.117) underwent a period of flaring activity in 2020. Detailed characterization of the broad-band emission of the source was achieved thanks to a multi-wavelength (MWL) campaign triggered by the Large Area Telescope (LAT) on board the Fermi satellite in the high-energy...
PG 1553+113 is a high-frequency peaked BL Lac object with a redshift of 0.433, detected by the current generation of Imaging Atmospheric Cherenkov Telescopes up to approximately 1 TeV. Interestingly, the continuous gamma-ray light curve recorded by Fermi-LAT since 2008 has shown a periodic modulation of 2.18 ± 0.08 years at energies above 100 MeV and 1 GeV. Additionally, the source displays...
The flat spectrum radio quasar OP 313 showed extremely intense $\gamma$-ray activity from November 2023 to March 2024, as observed by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. This initiated a large number of follow-up campaigns at all wavelengths, resulting in a confirmation of the increase of the source activity from the radio to very high energy (VHE) bands....
The gravitational-wave (GW) cosmology community has been developing techniques and methodologies to infer the cosmological parameters and investigate the black hole population with Compact Binary Coalescences (CBCs) without an electromagnetic counterpart, commonly referred to as dark sirens.
In this study, our focus lies on the method based on galaxy catalogs such as GLADE+, a composite...
The joint detection of a gravitational wave (GW) signal and a short Gamma-Ray Burst (GRB) from a binary neutron star merger in 2017 proved that short GRBs are multi-messenger sources. It is thus fundamental to understand and model the afterglow emission of short GRBs in order to improve our follow-up strategies for detecting the electromagnetic counterparts of GW events. It is widely accepted...
Understanding the interaction of massive black hole binaries with their gaseous environment is crucial since at sub-parsec scales the binary is too wide for gravitational wave emission to take over and to drive the two black holes to merge.
Furthermore the presence of a gaseous disc around sub-pc massive black hole binaries can trigger electromagnetic emission that can be detected by the...
Compact symmetric objects (CSOs) are sources with radio lobe emission on both sides of an active nucleus and an overall size of less than one kpc.
From the detection of 3 CSOs by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope, we know that the emission from these objects can extend into the GeV band. Surprisingly, the first LHAASO catalog reported a TeV source,...
Photons, neutrinos, gravitational waves and cosmic rays may originate from the same source regions, so a multi-messenger approach is crucial for a better understanding of the physics behind the production and propagation of these messengers. In this context, the Pierre Auger Observatory plays a key role to investigate the highest-energy primary particles, given its ability to distinguish...
The Dark Matter Particle Explorer (DAMPE) is a satellite-based detector designed for precise Galactic cosmic ray studies and indirect dark matter search. Since its launch in December 2015, DAMPE has been continuously collecting data on high-energy cosmic particles, with excellent statistics and particle identification capabilities, thanks to a large geometric factor and a good energy...
In recent years multifrequency polarimetry is emerging as a powerful tool for investigating blazar jets, especially with the advent of the Imaging X-ray Polarimetry Explorer (IXPE) space observatory.
We study the polarization of High-Synchrotron Peaked (HSP) blazars, where both optical and X-ray emission are due to synchrotron radiation from a population of non-thermal electrons. We adopt an...
