Description
Chair: Ioana Maris
TBC
Andromeda galaxy (M31) represents our nearest large neighbor spiral galaxy with a distance of 785 kpc. Its close proximity allows us to optically resolve its stellar disk and bulge as two separate components. Although M31 spans 3.2º x 1º on the sky in optical light, the determination of its extension in γ rays remains controversial. We analyze about 12 years of Fermi-LAT data using the code...
Primary very high energy (VHE, E>100 GeV) gamma-rays from distant (redshift z>0.1) extragalactic gamma-ray sources are partially absorbed on extragalactic background light (EBL) photons by means of the pair production process \gamma\gamma\rightarrow e^{+}e^{-} with the subsequent formation of intergalactic electromagnetic cascades through inverse Compton scattering of secondary electrons...
One of the key challenges in astroparticle physics is the identification of the sources of cosmic rays at the highest energies (above 1 EeV). In this context, the search for neutral messenger particles in the ultra-high-energy (UHE) regime is of high interest. The sources of the gravitational waves (GWs) that can be observed with the current generation of GW detectors provide extreme...
The origin of gamma-ray radiation of extreme TeV blazars (ETBs) — active galactic nuclei with unusually hard observable spectra in the TeV energy region — is still poorly understood. This is especially unfortunate since ETB studies are important in extragalactic background light measurements, and extremely important in extragalactic magnetic field measurements and axion-like particle searches....
The mechanisms of origin of ultrahigh-energy gamma radiation are poorly studied. One way to find out is to search for temporal and directional coincidences of high-energy galactic neutrinos with photons of similar energies. The results of such a search could provide indications of the hadronic origin of this radiation. In this paper, we report on the search for photons with energies above 300...
This work presents an IceCube search for high-energy neutrinos from Ultra-Luminous Infrared Galaxies (ULIRGs). ULIRGs are the most luminous infrared objects on the sky, with infrared luminosities exceeding $10^{12}$ solar luminosities. They are mainly powered by starbursts that exhibit star-formation rates larger than 100 solar masses per year. In addition, an active galactic nucleus (AGN) can...
The Surface Detector of the Pierre Auger Observatory, an array of 1600 water-
Cherenkov stations in a triangular grid with 1500 m separation between
stations, has the capability to detect neutrinos with energy above 10^17 eV. The
identification through the special characteristics of highly inclined showers is
efficiently performed for neutrinos of all flavours interacting deep in...
The blazar Mrk421 (redshift z=0.031) is one of the brightest and closest BL Lac type objects, making it an ideal target to probe blazar jet physics. We present a detailed characterisation and theoretical interpretation of the broadband emission of Mrk 421, with a focus on the multi-band flux correlations. The extensive multi-wavelength observation campaign was organised in 2017, during which...
γ-ray bursts (GRBs) are transient cataclysmic events, whose role became central in the new multi-messenger era. In the present work I propose a novel investigation of the GRB emission mechanism, via time-resolved spectral analysis of the X-ray tails of bright GRB pulses observed with the XRT instrument onboard the Neil Gehrels Swift Observatory, discovering a unique relation between the...
