31. The Cherenkov transparency coefficient for the atmospheric monitoring and array calibration at the Cherenkov Telescope Array SouthStanislav Stefanik, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Opis: Reconstruction of energies of very-high-energy γ–rays observed by imaging atmospheric Cherenkov telescopes is affected by changes in the atmospheric conditions and the performance of telescope components. Reliable calibration schemes aimed at these effects are necessary for the forthcoming Cherenkov Telescope Array (CTA) to achieve its goals on the maximally allowed systematic uncertainty of the global energy scale. A possible means of estimating the atmospheric attenuation of Cherenkov light is the method of the Cherenkov transparency coefficient (CTC). The CTC is calculated using the telescope detection rates, dominated by the steady cosmic ray background, while properly correcting for the hardware and observational conditions.
The coefficient can also be used to relatively calibrate the optical throughput of telescopes on the assumption of homogeneous atmospheric transparency above the array. Using Monte Carlo simulations, we investigate here the potential of the CTC method for the atmospheric monitoring and telescope cross-calibration at the CTA array in the southern hemisphere. We focus on the feasibility of the method for the array of telescopes of three sizes in different observation configurations and under various levels of atmospheric attenuation.
Ključne besede: very-high-energy gamma-ray astronomy, Cherenkov Telescope Array (CTA) Observatory, imaging atmospheric Cherenkov telescopes (IACTs), atmospheric monitoring, IACT calibration
Objavljeno v RUNG: 14.11.2024; Ogledov: 287; Prenosov: 4
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32. Two-dimensional BC tracer model to distinguish between primary and secondary OC : lecture at The European Aerosol Conference 2024, 25. 8.-30. 8. 2024, Tampere, FinlandMatic Ivančič, Asta Gregorič, Gašper Lavrič, Bálint Alföldy, Irena Ježek, Iasonas Stavroulas, Martin Rigler, 2024, prispevek na konferenci brez natisa Opis: In this work, we propose an extension of this method. Using the Aethalometer model (Sandradewi et al., 2008), BC as a tracer for primary emitted aerosols can be successfully divided into two components – BCff related to the usage of fossil fuels and BCbb emitted from biomass burning. Because the OC/BC ratio is expected to be different for fossil fuels and biomass burning, we can similarly introduce the two components of POC – a fossil fuel-related POCff and a biomass-burning-related POCbb.
Ključne besede: BC tracer model, secondary organic carbon, black carbon
Objavljeno v RUNG: 14.11.2024; Ogledov: 298; Prenosov: 1
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33. Using muon rings for the optical throughput calibration of the Cherenkov Telescope ArrayMarkus Gaug, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Opis: Muon ring images observed with Imaging Atmospheric Cherenkov Telescopes (IACTs) provide a powerful means to calibrate the optical throughput of IACTs and monitor their optical point spread function. We investigate whether muons ring images can be used as the primary optical throughput calibration method for the telescopes of the future Cherenkov Telescope Array (CTA) and find several additional systematic effects in comparison to previous works. To ensure that the method achieves the accuracy required by CTA, these systematic effects need to be taken into account and minor modifications to the hardware and analysis are necessary. We derive analytic estimates for the expected muon data rates to be used for optical throughput calibration, monitoring of the optical point spread function, with achievable statistical and systematic uncertainties, and explore the potential of muon ring images as a secondary method of camera pixel flat-fielding.
Ključne besede: very-high-energy gamma-ray astronomy, Cherenkov Telescope Array (CTA) Observatory, Imaging Atmospheric Cherenkov Telescopes, IACT optical throughput calibration, IACT camera pixel flat-fielding, IACT optical point spread function (PSF), muon ring images
Objavljeno v RUNG: 13.11.2024; Ogledov: 275; Prenosov: 5
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34. Status and performance results from NectarCAM : a camera for CTA medium sized telescopesThomas Tavernier, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Opis: The Cherenkov Telescope Array (CTA) will be the first ground-based observatory for gamma-ray astronomy. With more than a hundred of 4th generation of Imaging Atmospheric Cherenkov Telescopes (IACTs) distributed in two large arrays, CTA will reach unprecedented sensitivity, angular resolution, and spectral coverage. Three classes of IACTs – 40 Medium-Sized Telescopes (MSTs), 8 Large-Sized Telescopes (LSTs) and 70 Small-Sized Telescopes (SSTs) – are required to cover the full CTA energy range (20 GeV to 300 TeV).
NectarCAM is a Cherenkov camera which is designed to equip medium sized telescopes of CTA, covering the central energy range from 100 GeV to 30 TeV, with a field of view of 8 degrees. It is based on a modular design with data channels using the NECTAr chip, which is equipped with both GHz sampling Switched Capacitor Array and 12-bit Analog to Digital Converter (ADC). The camera will comprise 265 modules, each consisting of 7 photomultiplier Tubes (PMTs) and a Front-End Board performing the data capture, sending the data over the Ethernet after the trigger decision at rates up to 10 kHz.
This contribution provides an overview of the status of the first NectarCAM camera currently under integration in CEA Paris-Saclay (France). Furthermore, we will discuss the calibration strategies and present performance results from the CEA Paris-Saclay test bench and from the first data taken under a real sky on the prototype of medium sized telescope (MST) structure in Adlershof (Germany).
Ključne besede: very-high-energy gamma-ray astronomy, Cherenkov Telescope Array (CTA) Observatory, Imaging Atmospheric Cherenkov Telescopes, medium-sized telescopes, NectarCAM IACT camera
Objavljeno v RUNG: 13.11.2024; Ogledov: 317; Prenosov: 4
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35. Lahko v Sloveniji ostanemo brez določenih vinskih sort?2024, intervju Opis: Podnebne spremembe slovenskim vinarjem povzročajo velike preglavice. Ob toplih pomladih trte vzbrstijo vse bolj zgodaj, na mlade poganjke pa nato preži pozeba. Če ji vinogradi uidejo, je nato pred njimi burno poletje s sušo in vročino na eni ter neurji in točo na drugi strani. Kako vse skupaj vpliva na kakovost vina in kakšni so obeti za slovenske vinarje? Odgovarjata Guillaume Antalick in Jan Reščič s fakultete za vinogradništvo in vinarstvo Univerze v Novi Gorici.
Ključne besede: podnebne spremembe, vinogradništvo, vinska trta, prilagajanje
Objavljeno v RUNG: 13.11.2024; Ogledov: 226; Prenosov: 1
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36. The transient program of the Cherenkov Telescope ArrayFabian Schűssler, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Opis: The Cherenkov Telescope Array (CTA) is the next generation high-energy gamma-ray
observatory. It will improve the sensitivity of current instruments up to an order of magnitude, while providing energy coverage for photons from 20 GeV to at least 300 TeV to reach high redshifts and extreme accelerators and will give access to the shortest time-scale phenomena. CTA is thus a uniquely powerful instrument for the exploration of the violent and variable universe.
The ability to probe short timescales at the highest energies will allow CTA to explore the
connection between accretion and ejection phenomena surrounding compact objects, investigate the processes occurring in relativistic outflows, and open up significant phase space for serendipitous discoveries. Aiming at playing a central role in the era of multi-messenger astrophysics, the CTA Transient program includes follow-up observations of a broad range of multi-wavelength and multi-messenger alerts, ranging from Galactic compact object binary systems to novel phenomena like Fast Radio Bursts. A promising case is that of gamma-ray bursts (GRBs), where CTA will for the first time enable high-statistics measurements above ∼ 10 GeV, probing new spectral components and shedding light on the physical processes at work in these systems. Dedicated programs searching for very-high-energy (VHE) gamma-ray counterparts to gravitational waves and high-energy neutrinos complete the CTA transients program.
This contribution will introduce and outline the CTA Transients program. We will provide an overview of the various science topics and discuss the links to multi-messenger and
multi-wavelength observations.
Ključne besede: very-high-energy (VHE) gamma rays, the Cherenkov Telescope Array (CTA) Observatory, transient astrophysical phenomena, relativistic outflows, gamma-ray bursts
Objavljeno v RUNG: 12.11.2024; Ogledov: 242; Prenosov: 4
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37. The Cherenkov Telescope Array view of the Galactic Center regionAion Viana, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Opis: Among all the high-energy environments of our Galaxy, the Galactic Center (GC) region is
definitely the richest. It harbors a large amount of non-thermal emitters, including the closest supermassive black hole, dense molecular clouds, regions with strong star forming activity, multiple supernova remnants and pulsar wind nebulae, arc-like radio structures, as well as the base of what may be large-scale Galactic outflows, possibly related to the Fermi Bubbles. It also
contains a strong diffuse TeV gamma-ray emission along the Galactic ridge, with a disputed origin, including the presence of a possible Pevatron, unresolved sources, and an increased relevance of the diffuse sea of cosmic rays. This very rich region will be one of the key targets for the next generation ground-based observatory for gamma-ray astronomy, the Cherenkov Telescope Array (CTA). Here we review the CTA science case for the study of the GC region, and present the planned survey strategy. These observations are simulated and we assess CTA’s potential to better characterize the origin and nature of a selection of gamma-ray sources in the region.
Ključne besede: Galactic Center (GC) region, the Cherenkov Telescope Array (CTA) Observatory, supermassive black hole, molecular clouds, star forming regions
Objavljeno v RUNG: 12.11.2024; Ogledov: 253; Prenosov: 4
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38. Slovenka na Japonskem : pogovor v oddaji Z ljudmi na poti na Radiu Ognjišče, 10. 11. 2024Tina Škorjanc, 2024, radijski ali tv dogodek Opis: Pogledali smo na Japonsko, kjer približno leto dni živi in raziskuje dr. Tina Škorjanc. Sogovornica je Slovenijo za daljše obdobje prvič zapustila že pri svojih osemnajstih, ko se je odpravila na študij v Združene arabske emirate. Pozneje je študirala in raziskovalno delovala še v Argentini in Združenih državah Amerike, za krajše obdobje pa tudi v Šanghaju in Sydneyu. V oddaji je spregovorila o življenju v tujini, japonskih mestih in naravi ter njenih prebivalcih.
Ključne besede: pogovor, izobraževanje, Japonska, raziskovalno delo, Japonci, Kjoto
Objavljeno v RUNG: 12.11.2024; Ogledov: 227; Prenosov: 1
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39. Na Japonskem je tatu tabu : Globalna Vas2023, radijska ali televizijska oddaja, podkast, intervju, novinarska konferenca Opis: December je prazničen mesec, zato ga bomo preživeli "v ožjem družinskem krogu" – kot se spodobi. No, v kontekstu oddaje Globalna vas ta "ožji krog" pomeni ves planet, pridevnik "družinski" pa se nanaša na razvejeno mrežo naših gostov, ki smo jih spoznali skozi leta. V posebni seriji oddaj V ožjem družinskem krogu tako kličemo že davno pridružene člane naše globalnovaške družine, s katerimi se nismo slišali že leta, ter preverjamo, kje in kako so danes. V prvi oddaji se pogovarjamo s Tino Škorjanc, ki je prav v času svojega prvega gostovanja pri nas pred dobrimi sedmimi leti New York zamenjala za Abu Dabi, danes pa živi v Kjotu na Japonskem.
Ključne besede: Japonska, Slovenci v tujini, Kjoto
Objavljeno v RUNG: 11.11.2024; Ogledov: 187; Prenosov: 2
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40. Postnatal dynamics of Zeb2 expression in rat brain : analysis of novel 3′ UTR sequence reveals a miR-9 interacting siteKlara Kropivšek, Jasmine Pickford, David A. Carter, 2014, izvirni znanstveni članek Opis: ZEB2 is a transcription factor with established roles in neurogenesis but no defined function in postnatal brain despite extensive neuronal expression in telencephalic structures. Multiple, incompletely annotated transcripts derive from the Zeb2 locus; the purpose of the present study was to structurally characterize rat brain Zeb2 transcripts with respect to 3′ untranslated (UTR) sequence in order to understand Zeb2 transcript regulation including possible interactions with regulatory molecules such as neuronal miRNAs. We cloned a 5054-nucleotide Zeb2 3′ UTR that is included in the most abundant Zeb2 transcript in neonatal rat brain. Unique features of the distal 3′ UTR region included a number of brain-specific miRNA target sites; a highly conserved miR-9 target site at 3′ UTR position 4097 was selected for functional verification in transfection experiments. Parallel analysis of Zeb2 transcript, ZEB2 protein and miR-9 levels across postnatal brain cortical development revealed a significant accumulation of ZEB2 protein levels only between postnatal days P2 and P5 that was associated with an acute loss of postnatal miR-9 expression in cortex. These studies demonstrate novel features of Zeb2 gene expression in postnatal rat brain and highlight the importance of full transcript annotation for identifying the complement of potential transcript-interacting regulators.
Ključne besede: transcription factor, RNA, untranslated region, miRNA, brain, rat
Objavljeno v RUNG: 11.11.2024; Ogledov: 190; Prenosov: 3
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