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Opis: The Cherenkov Telescope Array (CTA) is the next generation ground-based observatory for γ-ray astronomy at energies above 30 GeV. Thanks to its unique capabilities, CTA observations will address a plethora of open questions in astrophysics, ranging from the origin of cosmic messengers to the exploration of the frontiers of physics. In this note, we present a comprehensive sensitivity study to assess the potential of CTA to measure the γ-ray absorption on the extragalactic background light (EBL), to constrain or detect intergalactic magnetic fields (IGMFs), and probe physics beyond the standard model such as axion-like particles (ALPs) and Lorentz invariance violation (LIV), which could modify the γ-ray spectra features expected from EBL absorption. Our results suggest that CTA will have unprecedented sensitivity to detect IGMF signatures and will probe so-far unexplored regions of the LIV and ALP parameter space. Furthermore, an indirect measurement of the EBL and of its evolution will be performed with unrivaled precision.
Ključne besede: very-high-energy gamma rays, the Cherenkov Telescope Array (CTA) Observatory, extragalactic background light (EBL), intergalactic magnetic fields (IGMFs), axion-like particles (ALPs), Lorentz invariance violation (LIV)
Objavljeno v RUNG: 07.11.2024; Ogledov: 291; Prenosov: 4
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Opis: Context. We present the results of the reverberation monitoring of the Mg II broad line and Fe II pseudocontinuum for the luminous quasar CTS C30.10 (z = 0.90052) with the Southern African Large Telescope in 2012–2021. Aims. We aimed at disentangling the Mg II and UV Fe II variability and the first measurement of UV Fe II time delay for a distant quasar. Methods. We used several methods for the time-delay measurements and determined the Fe II and Mg II time delays. We also performed a wavelength-resolved time delay study for a combination of Mg II and Fe II in the 2700–2900 Å rest-frame wavelength range. Results. We obtain a time delay for Mg II of 275.5−19.5+12.4 days in the rest frame, and we have two possible solutions of 270.0−25.3+13.8 days and 180.3−30.0+26.6 in the rest frame for Fe II. Combining this result with the old measurement of Fe II UV time delay for NGC 5548, we discuss for first time the radius-luminosity relation for UV Fe II with the slope consistent with 0.5 within the uncertainties. Conclusions. Because the Fe II time delay has a shorter time-delay component but the lines are narrower than Mg II, we propose that the line-delay measurement is biased toward the part of the broad line region (BLR) facing the observer. The bulk of the Fe II emission may arise from the more distant BLR region, however, the region that is shielded from the observer.
Ključne besede: accretion, accretion disks / quasars: emission lines / quasars: individual: CTS C30.10 / techniques: spectroscopic / techniques: photometric
Objavljeno v RUNG: 13.11.2023; Ogledov: 1816; Prenosov: 5
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Ključne besede: lidar, remote sensing, CTA, CTAO, Cumbre Vieja, atmospheric monitoring, volcano
Objavljeno v RUNG: 13.02.2023; Ogledov: 1900; Prenosov: 22
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Ključne besede: organic/inorganic hybrid solar cells, conjugated polymer, ZnO nanorod array
Objavljeno v RUNG: 16.01.2017; Ogledov: 5462; Prenosov: 0
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