Joint Observation of the Galactic Center with MAGIC and CTA-LST-1

MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes (IACTs), designed to detect very-high-energy gamma rays, and is operating in stereoscopic mode since 2009 at the Observatorio del Roque de Los Muchachos in La Palma, Spain. In 2018, the prototype IACT of the Large-Sized Telescope (LST-1) for the Cherenkov Telescope Array, a next-generation ground-based gamma-ray observatory, was inaugurated at the same site, at a distance of approximately 100 meters from the MAGIC telescopes. Using joint observations between MAGIC and LST-1, we developed a dedicated analysis pipeline and established the threefold telescope system via software, achieving the highest sensitivity in the northern hemisphere. Based on this enhanced performance, MAGIC and LST-1 have been jointly and regularly observing the Galactic Center, a region of paramount importance and complexity for IACTs. In particular, the gamma-ray emission from the dynamical center of the Milky Way is under debate. Although previous measurements suggested that a supermassive black hole Sagittarius A* plays a primary role, its radiation mechanism remains unclear, mainly due to limited angular resolution and sensitivity. The enhanced sensitivity in our novel approach is thus expected to provide new insights into the question. We here present the current status of the data analysis for the Galactic Center joint MAGIC and LST-1 observations

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* * Izvorni nau�ni rad (Original scientific paper

Original scientific paper

The effect of reversing current deposition on the apparent density of electrolytic copper powde

Original scientific paper Spectrophotometric investigation of the Fe(III)–disulphonated hydroquinone complex

Abstract: Iron(III) form an indigo-blue complex with the disulphonated product of hydroquinone (K2S2Hy) in acid media with an absorption maxima at 600 nm. The time stability of the complex, dependence of the complex absorbance on pH and the influence of temperature and solvent were followed on the basis of spectrophotometric measurements. Using the Job, mole ratio and Henry–Franck–Ostwald methods, the composition and relative stability constant of this complex, in 80 vol. % ethanol as solvent, were determined (1:1; log � ’ 293 = 3.37). A new spectrophotometric method for the determination of iron has been developed and the calibration curve is linear in the concentrationrangefrom0.65to6.45�gcm-3. The effects of foreign ions on the determination of iron were investigated in order to assess the selectivity of the method. The method was applied for the determination of Fe(III) in the natural juice of beet

cheto-smectite of the black marl

Abstract: The Cretaceus-Tertiary (KT) boundary at Stevns Klint (the Højerup succession), Fiskeler, consists of a thin red clay layer overlain by a thick one of black marl. These two layers are made up mainly from cheto-smectite and biogenic calcite. The black marl shows an enhanced concentration of Ni (655 ppm) within its smectite fraction. Additionally, its carbonate fraction also shows an enhanced concentration of Ni (245 ppm). It is reasoned that these enrichments represent a sudden and rapid input of high amounts of Ni into the late Cretaceus seawater at Stevns Klint. The ultimate source of Ni in both the carbonate and smectite fractions of the black marl was probably impact fallout, produced by the KT asteroidal impact, deposited on the nearby soil and leached by the (acid) surface waters. The geochemistry of the Ni supports the hypothesis that the smectite of this marl most likely has a local (marine or terrestrial) provenance and was probably redeposited, after its formation, from the original site to its present location at the KT boundary

Original scientific paper Geochemistry of the Cretaceous-Tertiary boundary (Fish Clay) at Stevns Klint (Denmark): Ir, Ni and Zn in kerogen

Abstract: Geochemical analyses of trace metals (Ir, Ni and Zn) in the kerogen of the black marl of the Cretaceous-Tertiary boundary succession (Fish Clay) at Stevns Klint (H�jerup Church) were undertaken. The data for this kerogen were in accordance with a previous hypothesis1 that this (insoluble) geoorganic polymer was derived from humic substances (mainly humic acids) of a nearshore soil. Substantial proportions of Ir, Ni and Zn within the kerogen structure were probably contained in these substances arriving at the sedimentary site. It is proposed that these humics were probably transported by acid surface waters (induced by the KT asteroid impact) into the shallow marine basin of Stevns Klint. It is also suggested that local leaching/weathering of the asteroidal impact fallout on the land near these waters played an important role in providing Ir, Ni and Zn for these substances. Apparently, Ir, Ni and Zn of the kerogen were created by the chondritic component of the impact ejecta fallout

Speech/Gesture Interface to a Visual Computing Environment for Molecular Biologists

Recent progress in 3-D, immersive display and virtual reality (VR) technologies has made possible many exciting applications, for example, interactive visualization of complex scientific data. To fully exploit this potential there is a need for "natural" interfaces that allow the manipulation of such displays without cumbersome attachments. In this paper we describe the use of visual hand gesture analysis and speech recognition for developing a speech/gesture interface for controlling a 3-D display. The interface enhances an existing application, VMD, which is a VR visual computing environment for molecular biologists. The free hand gestures are used for manipulating the 3-D graphical display together with a set of speech commands. We describe the visual gesture analysis and the speech analysis techniques used in developing this interface. The dual modality of speech/gesture is found to greatly aid the interaction capability. 1 Introduction Although there has been tremendous progres..