41. Dark matter search in dwarf irregular galaxies with the Fermi Large Area TelescopeViviana Gammaldi, Judit Pérez Romero, Javier Coronado-Blázquez, Mattia di Mauro, Ekaterina Karukes, Miguel Sánchez-Conde, Paolo Salucci, 2021, izvirni znanstveni članek Opis: We analyze 11 years of Fermi-Large Area Telescope (LAT) data corresponding to the sky regions of seven dwarf irregular (dIrr) galaxies. DIrrs are dark matter (DM)-dominated systems, proposed as interesting targets for the indirect search of DM with gamma rays. The galaxies represent interesting cases with a strong disagreement between the density profiles (core versus cusp) inferred from observations and numerical simulations. In this work, we addressed the problem by considering two different DM profiles, based on both the fit to the rotation curve (in this case, a Burkert cored profile) and results from N-body cosmological simulations (i.e., Navarro-Frenk-White cuspy profile). We also include halo substructure in our analysis, which is expected to boost the DM signal by a factor of 10 in halos such as those of dIrrs. For each DM model and dIrr, we create a spatial template of the expected DM-induced gamma-ray signal to be used in the analysis of Fermi-LAT data. No significant emission is detected from any of the targets in our sample. Thus, we compute upper limits on the DM annihilation cross section versus mass parameter space.
Among the seven dIrrs, we find IC10 and NGC6822 to yield the most stringent individual constraints, independently of the adopted DM profile. We also produce combined DM limits for all objects in the sample, which turn out to be dominated by IC10 for all DM models and annihilation channels, i.e., b¯b, τ+τ−, and W+W−. The strongest constraints are obtained for b¯b and are at the level of <σv>∼7×10−26 cm3 s−1 at mχ ∼ 6 GeV. Though these limits are a factor of ∼3 higher than the thermal relic cross section at low weakly interacting massive particles masses, they are independent from and complementary to those obtained by means of other targets. Ključne besede: Dark matter, gamma-ray astronomy, galaxies, astronomical masses and mass distributions Objavljeno v RUNG: 26.01.2023; Ogledov: 1011; Prenosov: 0 Gradivo ima več datotek! Več... |
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43. Multi-messenger studies with the Pierre Auger ObservatoryLukas Zehrer, Andrej Filipčič, Gašper Kukec Mezek, Jon Paul Lundquist, Samo Stanič, Marta Trini, Serguei Vorobiov, Marko Zavrtanik, Danilo Zavrtanik, 2021, objavljeni znanstveni prispevek na konferenci Opis: Over the past decade the multi-messenger astrophysics has emerged as a distinct discipline,
providing unique insights into the properties of high-energy phenomena in the Universe. The
Pierre Auger Observatory, located in Malargüe, Argentina, is the world’s largest cosmic ray
detector sensitive to photons, neutrinos, and hadrons at ultra-high energies. Using its data, stringent
limits on photon and neutrino fluxes at EeV energies have been obtained. The collaboration uses
the excellent angular resolution and the neutrino identification capabilities of the Observatory
for follow-up studies of events detected in gravitational waves or other messengers, through
cooperation with global multi-messenger networks. We present a science motivation together
with an overview of the multi-messenger capabilities and results of the Pierre Auger Observatory. Ključne besede: high-energy cosmic phenomena, multi-messenger astrophysical studies, cosmic rays, gamma-rays, neutrinos, Pierre Auger Observatory Objavljeno v RUNG: 06.05.2022; Ogledov: 1516; Prenosov: 0 Gradivo ima več datotek! Več... |
44. Identification of point sources in gamma rays using U-shaped convolutional neural networks and a data challengeBoris Panes, Christopher Eckner, Luc Hendriks, Sascha Caron, Klaas Dijkstra, Gudlaugur Johannesson, Roberto Ruiz de Austri, Gabrijela Zaharijas, 2021, izvirni znanstveni članek Ključne besede: gamma rays, astroparticle physics, data analysis Objavljeno v RUNG: 17.02.2022; Ogledov: 1594; Prenosov: 7 Povezava na celotno besedilo Gradivo ima več datotek! Več... |
45. Catalog of long-term transient sources in the first 10 yr of Fermi-LAT dataL. Baldini, J. Ballet, D. Bastieri, J. Becerra Gonzalez, R. Bellazzini, A. Berretta, E. Bissaldi, R. D. Blandford, E. D. Bloom, Gabrijela Zaharijas, 2021, izvirni znanstveni članek Ključne besede: high energy astrophysics, active galactic nuclei, gamma-ray bursts, solar flares, solar gamma-ray emission Objavljeno v RUNG: 17.02.2022; Ogledov: 1755; Prenosov: 40 Povezava na celotno besedilo Gradivo ima več datotek! Več... |
46. First Fermi-LAT solar flare catalogM. Ajello, L. Baldini, D. Bastieri, R. Bellazzini, A. Berretta, E. Bissaldi, R. D. Blandford, R. Bonino, P. Bruel, Gabrijela Zaharijas, 2021, izvirni znanstveni članek Ključne besede: solar flares, solar gamma-ray emission, gamma-ray sources, gamma-ray telescopes, catalogs Objavljeno v RUNG: 17.02.2022; Ogledov: 2181; Prenosov: 112 Povezava na celotno besedilo Gradivo ima več datotek! Več... |
47. Gamma rays from fast black-hole windsM. Ajello, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, R. Bellazzini, A. Berretta, E. Bissaldi, R. D. Blandford, E. D. Bloom, Gabrijela Zaharijas, 2021, izvirni znanstveni članek Ključne besede: active galactic nuclei, galactic winds, gamma-rays Objavljeno v RUNG: 17.02.2022; Ogledov: 1772; Prenosov: 111 Povezava na celotno besedilo Gradivo ima več datotek! Več... |
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50. Multi-messenger astrophysics with THESEUS in the 2030sRiccardo Ciolfi, Giulia Stratta, Marica Branchesi, Bruce Gendre, Stefan Grimm, Jan Harms, Gavin Paul Lamb, Antonio Martin-Carrillo, Ayden McCann, Andreja Gomboc, 2021, izvirni znanstveni članek Ključne besede: multi-messenger astrophysics, Gamma-ray bursts, compact binary merger, Kilonova Objavljeno v RUNG: 02.11.2021; Ogledov: 1802; Prenosov: 0 Gradivo ima več datotek! Več... |