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83. The Western South Slavic verbal suffix -nV/-neEma Štarkl, Stefan Milosavljević, Marko Simonović, Boban Arsenijević, 2025, complete scientific database of research data Keywords: Western South Slavic, suffix -n, verbal morphology, semelfactive, diminution, theme vowel
Published in RUNG: 06.03.2025; Views: 490; Downloads: 5
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85. The diversity of strongly interacting Type IIn supernovaeI. Salmaso, E. Cappellaro, L. Tartaglia, J. P. Anderson, S. Benetti, Mateusz Bronikowski, Y.-Z. Cai, P. Charalampopoulos, W. T. Chen, E. Concepcion, Tanja Petrushevska, 2025, original scientific article Abstract: Context. At late stages, massive stars experience strong mass-loss rates, losing their external layers and thus producing a dense H-rich circumstellar medium (CSM). After the explosion of a massive star, the collision and continued interaction of the supernova (SN) ejecta with the CSM power the SN light curve through the conversion of kinetic energy into radiation. When the interaction is strong, the light curve shows a broad peak and high luminosity that lasts for several months. For these SNe, the spectral evolution is also slower compared to non-interacting SNe. Notably, energetic shocks between the ejecta and the CSM create the ideal conditions for particle acceleration and the production of high-energy (HE) neutrinos above 1 TeV.
Aims. We study four strongly interacting Type IIn SNe, 2021acya, 2021adxl, 2022qml, and 2022wed, in order to highlight their peculiar characteristics, derive the kinetic energy of their explosion and the characteristics of the CSM, infer clues on the possible progenitors and their environment, and relate them to the production of HE neutrinos.
Methods. We analysed spectro-photometric data of a sample of interacting SNe to determine their common characteristics and derive the physical properties (radii and masses) of the CSM and the ejecta kinetic energies and compare them to HE neutrino production models.
Results. The SNe analysed in this sample exploded in dwarf star-forming galaxies, and they are consistent with energetic explosions and strong interaction with the surrounding CSM. For SNe 2021acya and 2022wed, we find high CSM masses and mass-loss rates, linking them to very massive progenitors. For SN 2021adxl, the spectral analysis and less extreme CSM mass suggest a stripped-envelope massive star as a possible progenitor. SN 2022qml is marginally consistent with being a Type Ia thermonuclear explosion embedded in a dense CSM. The mass-loss rates for all the SNe are consistent with the expulsion of several solar masses of material during eruptive episodes in the last few decades before the explosion. Finally, we find that the SNe in our sample are marginally consistent with HE neutrino production.
Keywords: astronomy, neutrinos, supernovae
Published in RUNG: 04.03.2025; Views: 493; Downloads: 8
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86. Eruptive mass loss less than a year before the explosion of superluminous supernovae : I. The cases of SN 2020xga and SN 2022xgcA. Gkini, C. Fransson, Ragnhild Lunnan, S. Schulze, F. Poidevin, N. Sarin, R. Könyves-Tóth, Jesper Sollerman, Mateusz Bronikowski, Tanja Petrushevska, 2025, original scientific article Abstract: We present photometric and spectroscopic observations of SN 2020xga and SN 2022xgc, two hydrogen-poor superluminous supernovae (SLSNe-I) at z = 0.4296 and z = 0.3103, respectively, which show an additional set of broad Mg II absorption lines, blueshifted by a few thousands kilometer second−1 with respect to the host galaxy absorption system. Previous work interpreted this as due to resonance line scattering of the SLSN continuum by rapidly expanding circumstellar material (CSM) expelled shortly before the explosion. The peak rest-frame g-band magnitude of SN 2020xga is −22.30 ± 0.04 mag and of SN 2022xgc is −21.97 ± 0.05 mag, placing them among the brightest SLSNe-I. We used high-quality spectra from ultraviolet to near-infrared wavelengths to model the Mg II line profiles and infer the properties of the CSM shells. We find that the CSM shell of SN 2020xga resides at ∼1.3 × 1016 cm, moving with a maximum velocity of 4275 km s−1, and the shell of SN 2022xgc is located at ∼0.8 × 1016 cm, reaching up to 4400 km s−1. These shells were expelled ∼11 and ∼5 months before the explosions of SN 2020xga and SN 2022xgc, respectively, possibly as a result of luminous-blue-variable-like eruptions or pulsational pair instability (PPI) mass loss. We also analyzed optical photometric data and modeled the light curves, considering powering from the magnetar spin-down mechanism. The results support very energetic magnetars, approaching the mass-shedding limit, powering these SNe with ejecta masses of ∼7 − 9 M⊙. The ejecta masses inferred from the magnetar modeling are not consistent with the PPI scenario pointing toward stars > 50 M⊙ He-core; hence, alternative scenarios such as fallback accretion and CSM interaction are discussed. Modeling the spectral energy distribution of the host galaxy of SN 2020xga reveals a host mass of 107.8 M⊙, a star formation rate of 0.96−0.26+0.47 M⊙ yr−1, and a metallicity of ∼0.2 Z⊙.
Keywords: eruptive mass, loss, supernovae
Published in RUNG: 04.03.2025; Views: 556; Downloads: 7
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87. Characterization of brown carbon absorption in different European environments through source contribution analysisHector Navarro-Barboza, Jordi Rovira, Vincenzo Obiso, Andrea Pozzer, Marta Via, Andrés Alastuey, Xavier Querol, Jesús Yus-Díez, Matic Ivančič, Martin Rigler, 2025, original scientific article Abstract: Brown carbon (BrC) is a fraction of organic aerosol (OA) that absorbs radiation in the ultraviolet and short visible wavelengths. Its contribution to radiative forcing is uncertain due to limited knowledge of its imaginary refractive index (k). This study investigates the variability of k for OA from wildfires, residential, shipping, and traffic emission sources over Europe. The Multiscale Online Nonhydrostatic Atmosphere Chemistry (MONARCH) model simulated OA concentrations and source contributions, feeding an offline optical tool to constrain k values at 370 nm. The model was evaluated against OA mass concentrations from aerosol chemical speciation monitors (ACSMs) and filter sample measurements, as well as aerosol light absorption measurements at 370 nm derived from an Aethalometer™ from 12 sites across Europe. Results show that MONARCH captures the OA temporal variability across environments (regional, suburban, and urban background). Residential emissions are a major OA source in colder months, while secondary organic aerosol (SOA) dominates in warmer periods. Traffic is a minor primary OA contributor. Biomass and coal combustion significantly influence OA absorption, with shipping emissions also notable near harbors. Optimizing k values at 370 nm revealed significant variability in OA light absorption, influenced by emission sources and environmental conditions. Derived k values for biomass burning (0.03 to 0.13), residential (0.008 to 0.13), shipping (0.005 to 0.08), and traffic (0.005 to 0.07) sources improved model representation of OA absorption compared to a constant k. Introducing such emission source-specific constraints is an innovative approach to enhance OA absorption in atmospheric models.
Keywords: aerosols, brown carbon, source contribution analysis
Published in RUNG: 04.03.2025; Views: 564; Downloads: 6
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88. Algebraic structures and graph theoryscientific monograph Keywords: groups, ring, field, lattice, hypergroups, hyperring, hyperfield, graph, hypergraph, equivalence relation, operation, hyperoperation
Published in RUNG: 04.03.2025; Views: 490; Downloads: 5
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