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82. 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, original scientific article Found in: ključnih besedah
Keywords: active galactic nuclei, galactic winds, gamma-rays
Published: 17.02.2022; Views: 858; Downloads: 64
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83. 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, original scientific article Found in: ključnih besedah
Summary of found: ...solar flares, solar gamma-ray emission, gamma-ray sources, gamma-ray telescopes, catalogs...
Keywords: solar flares, solar gamma-ray emission, gamma-ray sources, gamma-ray telescopes, catalogs
Published: 17.02.2022; Views: 962; Downloads: 69
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85. 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, original scientific article Found in: ključnih besedah
Summary of found: ...high energy astrophysics, active galactic nuclei, gamma-ray bursts, solar flares, solar gamma-ray emission...
Keywords: high energy astrophysics, active galactic nuclei, gamma-ray bursts, solar flares, solar gamma-ray emission
Published: 17.02.2022; Views: 848; Downloads: 26
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86. 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, original scientific article Found in: ključnih besedah
Keywords: gamma rays, astroparticle physics, data analysis
Published: 17.02.2022; Views: 737; Downloads: 4
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87. 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, published scientific conference contribution Abstract: 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.
Found in: ključnih besedah
Summary of found: ...cosmic phenomena, multi-messenger astrophysical studies, cosmic rays, gamma-rays, neutrinos, Pierre Auger Observatory...
Keywords: high-energy cosmic phenomena, multi-messenger astrophysical studies, cosmic rays, gamma-rays, neutrinos, Pierre Auger Observatory
Published: 06.05.2022; Views: 652; Downloads: 0
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89. Dark matter search in dwarf irregular galaxies with the Fermi Large Area TelescopePaolo Salucci, Miguel Sánchez-Conde, Ekaterina Karukes, Mattia di Mauro, Javier Coronado-Blázquez, Viviana Gammaldi, Judit Pérez-Romero, 2021, original scientific article Abstract: 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.
Found in: ključnih besedah
Summary of found: ...for the indirect search of DM with gamma rays. The galaxies represent interesting cases with...
Keywords: Dark matter, gamma-ray astronomy, galaxies, astronomical masses and mass distributions
Published: 26.01.2023; Views: 178; Downloads: 0
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90. Spatial extension of dark subhalos as seen by Fermi-LAT and the implications for WIMP constraintsAlejandra Aguirre-Santaella, Judit Pérez-Romero, Miguel Sánchez-Conde, Javier Coronado-Blázquez, 2022, original scientific article Abstract: Spatial extension has been hailed as a “smoking gun” in the gamma-ray search of dark galactic subhalos, which would appear as unidentified sources for gamma-ray telescopes. In this work, we study the sensitivity of the Fermi-LAT to extended subhalos using simulated data based on a realistic sky model. We simulate spatial templates for a set of representative subhalos, whose parameters were derived from our previous work with N-body cosmological simulation data. We find that detecting an extended subhalo and finding an unequivocal signal of angular extension requires, respectively, a flux 2 to 10 times larger than in the case of a pointlike source. By studying a large grid of models, where parameters such as the WIMP mass, annihilation channel, or subhalo model are varied significantly, we obtain the response of the LAT as a function of the product of annihilation cross-section times the J-factor. Indeed, we show that spatial extension can be used as an additional “filter” to reject subhalos candidates among the pool of unidentified LAT sources, as well as a smoking gun for positive identification. For instance, typical angular extensions of a few tenths of a degree are expected for the considered scenarios. Finally, we also study the impact of the obtained LAT sensitivity to such extended subhalos on the achievable dark matter constraints, which are a few times less constraining than comparable point-source limits.
Found in: ključnih besedah
Summary of found: ...hailed as a “smoking gun” in the gamma-ray search of dark galactic subhalos, which would...
Keywords: dark matter, cosmic rays and astroparticles, gamma-ray astronomy, particle astrophysics, particle dark matter
Published: 26.01.2023; Views: 195; Downloads: 0
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