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1762. FR-0 jetted active galaxies : extending the zoo of candidate sites for UHECR accelerationLukas Merten, Margot Boughelilba, Anita Reimer, Paolo Da Vela, Serguei Vorobiov, Fabrizio Tavecchio, Giacomo Bonnoli, Jon Paul Lundquist, Chiara Righi, 2021, objavljeni znanstveni prispevek na konferenci Opis: Fanaroff-Riley (FR) 0 radio galaxies form a low-luminosity extension to the well-established ultra-high-energy cosmic-ray (UHECR) candidate accelerators FR-1 and FR-2 galaxies. Their much higher number density — up to a factor five times more numerous than FR-1 with z ≤ 0.05 — makes them good candidate sources for an isotropic contribution to the observed UHECR flux.
Here, the acceleration and survival of UHECR in prevailing conditions of the FR-0 environment are discussed.
First, an average spectral energy distribution (SED) is compiled based on the FR0CAT. These photon fields, composed of a jet and a host galaxy component, form a minimal target photon field for the UHECR, which will suffer from electromagnetic pair production, photo-disintegration, photo-meson production losses, and synchrotron radiation. The two most promising acceleration scenarios based on Fermi-I order and gradual shear acceleration are discussed as well as different
escape scenarios.
When an efficient acceleration mechanism precedes gradual shear acceleration, e.g., Fermi-I orothers, FR-0 galaxies are likely UHECR accelerators. Gradual shear acceleration requires a jet
Lorentz factor of Gamma>1.6, to be faster than the corresponding escape. In less optimistic models, a contribution to the cosmic-ray flux between the knee and ankle is expected to be relatively independent of the realized turbulence and acceleration.
Ključne besede: jetted active galaxies, FR-0 radiogalaxies, ultra-high energy cosmic rays, cosmic ray acceleration, cosmic ray energy losses
Objavljeno v RUNG: 16.08.2021; Ogledov: 1966; Prenosov: 3
 Celotno besedilo (1,13 MB) |
1763. Extrapolating FR-0 radio galaxy source properties from propagation of multi-messenger ultra-high energy cosmic raysJon Paul Lundquist, Lukas Merten, Serguei Vorobiov, Margot Boughelilba, Anita Reimer, Paolo Da Vela, Fabrizio Tavecchio, Giacomo Bonnoli, Chiara Righi, 2021, objavljeni znanstveni prispevek na konferenci Opis: Recently, it has been shown that relatively low luminosity Fanaroff-Riley type 0 (FR-0) radio galaxies are a good candidate source class for a predominant fraction of cosmic rays (CR) accelerated to ultra-high energies (UHE, E>10[sup]18 eV). FR-0s can potentially provide a significant fraction
of the UHECR energy density as they are much more numerous in the local universe than more energetic radio galaxies such as FR-1s or FR-2s (up to a factor of ∼5 with z≤0.05 compared to
FR-1s).
In the present work, UHECR mass composition and energy spectra at the FR-0 sources are estimated by fitting simulation results to the published Pierre Auger Observatory data. This fitting is done using a simulated isotropic sky distribution extrapolated from the measured FR-0 galaxy properties and propagating CRs in plausible extragalactic magnetic field configurations using the CRPropa3 framework. In addition, we present estimates of the fluxes of secondary photons and neutrinos created in UHECR interactions with cosmic photon backgrounds during
CR propagation. With this approach, we aim to investigate the properties of the sources with the help of observational multi-messenger data.
Ključne besede: jetted active galaxies, FR-0 radiogalaxies, ultra-high energy cosmic rays, extragalactic magnetic fields, UHECR propagation, UHECR interactions, cosmogenic photons, cosmogenic neutrinos
Objavljeno v RUNG: 16.08.2021; Ogledov: 1945; Prenosov: 3
Celotno besedilo (2,04 MB) |
1764. The Unmanned Systems Research Laboratory (USRL) : a new facility for UAV-based atmospheric observationsMaria Kezoudi, Christos Keleshis, Panayiota Antoniou, George Biskos, Murat Bronz, Christos Constantinides, Maximillien Desservettaz, Ru-Shan Gao, Joe Girdwood, Griša Močnik, 2021, izvirni znanstveni članek Opis: The Unmanned Systems Research Laboratory (USRL) of the Cyprus Institute is a new mobile exploratory platform of the EU Research Infrastructure Aerosol, Clouds and Trace Gases Research InfraStructure (ACTRIS). USRL offers exclusive Unmanned Aerial Vehicle (UAV)-sensor solutions that can be deployed anywhere in Europe and beyond, e.g., during intensive field campaigns through a transnational access scheme in compliance with the drone regulation set by the European Union Aviation Safety Agency (EASA) for the research, innovation, and training. UAV sensor systems play a growing role in the portfolio of Earth observation systems. They can provide cost-effective, spatial in-situ atmospheric observations which are complementary to stationary observation networks. They also have strong potential for calibrating and validating remote-sensing sensors and retrieval algorithms, mapping close-to-the-ground emission point sources and dispersion plumes, and evaluating the performance of atmospheric models. They can provide unique information relevant to the short- and long-range transport of gas and aerosol pollutants, radiative forcing, cloud properties, emission factors and a variety of atmospheric parameters. Since its establishment in 2015, USRL is participating in major international research projects dedicated to (1) the better understanding of aerosol-cloud interactions, (2) the profiling of aerosol optical properties in different atmospheric environments, (3) the vertical distribution of air pollutants in and above the planetary boundary layer, (4) the validation of Aeolus satellite dust products by utilizing novel UAV-balloon-sensor systems, and (5) the chemical characterization of ship and stack emissions. A comprehensive overview of the new UAV-sensor systems developed by USRL and their field deployments is presented here. This paper aims to illustrate the strong scientific potential of UAV-borne measurements in the atmospheric sciences and the need for their integration in Earth observation networks.
Ključne besede: landscape, proximity, still life, COVID-19, domesticity
Objavljeno v RUNG: 16.08.2021; Ogledov: 1690; Prenosov: 147
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1765. Dual in SlovenianFranc Marušič, Rok Žaucer, 2021, samostojni znanstveni sestavek ali poglavje v monografski publikaciji Opis: Slovenian is one of only three contemporary Slavic languages that productively uses the dual. The other two are Upper and Lower Sorbian. In this chapter, we will outline the present-day use of the dual in Slovenian, generally ignoring historical aspects, for which see, i.a., Tesnière (1925a), Belić (1934), Jakop (2008), Olander (2015). Also, the description will primarily be based on standard Slovenian as described/prescribed in Toporišič et al. (2001), mainly ignoring the great variation across different varieties
of Slovenian (cf. Tesnière 1925a,b, Jakop 2008) in the actual forms of dual marking and the extent to which dual forms are distinct from the plural. The paradigms presented in the next section exist in entirety only in few dialects and in the prescribed standard variety. A small number of dialects of the South West, along the border between Italy and Slovenia, and the dialects of the South, along the border with Croatia, are without most of the dual forms and in some cases without the dual altogether, but for the most part, different dialects exhibit different amounts of dual
forms. Central Slovenian dialects and dialects of the North and North-East use dual fully productively (cf. Jakop 2008 and Marušič et al. 2016 for a comprehensive map of the distribution of dual in Slovenian dialects).
Ključne besede: Slovenian, grammatical number, dual, meaning of dual
Objavljeno v RUNG: 13.08.2021; Ogledov: 1718; Prenosov: 0
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