208 research outputs found

    African small mammals = Petits mammifères africains

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    KiDS0239-3211: A new gravitational quadruple lens candidate

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    We report the discovery of a candidate to quadrupole gravitationally lensed system KiDS0239-3211 based on the public data release 3 of the KiDS survey and machine learning techniques

    A Revised Checklist of Mongolian Mammal Species

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    A revised annotated checklist of Mongolian mammals is presented, supplemented with comments on modifications in species- and genus-level taxonomy introduced over the last 30 years. The checklist includes 140 species compared to 124 species recognized three decades ago by SOKOLOV & ORLOV (1980). Since then, four species were newly described; seven species were registered for the first time on Mongolian territory. Names for more than 20 taxa have changed, on most occasions this change occurred not for purely nomenclatural reasons but rather as a result of taxonomic revisions at the species level which have elevated the rank of many nominal taxa treated previously as subspecies. Recent molecular studies have shown that many widespread Central Asian species, in fact, consist of several highly divergent phylogenetic lineages the taxonomic status of which is yet unclear. Therefore, further updates to our knowledge of mammal biodiversity in Mongolia are expected

    A Dipole Vortex Model of Obscuring Tori in Active Galaxy Nuclei

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    The torus concept as an essential structural component of active galactic nuclei (AGN) is generally accepted. Here, the situation is discussed when the torus "twisting" by the radiation or wind transforms it into a dipole toroidal vortex which in turn can be a source of matter replenishing the accretion disk. Thus emerging instability which can be responsible for quasar radiation flares accompanied by matter outbursts is also discussed. The "Matreshka" scheme for an obscuring vortex torus structure capable of explaining the AGN variability and evolution is proposed. The model parameters estimated numerically for the luminosity close to the Eddington limit agree well with the observations.Comment: 17 pages, 11 figures, version of this paper is published in Astronomy Report

    Self-education as a factor of sustainable professional growth specialist

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    The article is devoted to the problem of self-education of specialist in organization of new information. Information society is characterized as a knowledge society, where the key ones are access to information, ability to work with it and transform it into knowledge. Presents the recommendations for improving the effectiveness of the process of self-education for specialists and management of the organizations interested in the formation of highly qualified personnelРассматривается проблема самообразования специалистов организации в новых информационных условиях. Представлены рекомендации по повышению эффективности процесса самообразования для специалистов и руководства организаций, заинтересованного в формировании высококвалифицированного персонал

    KiDS-SQuaD: The KiDS Strongly lensed Quasar Detection project

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    New methods have been recently developed to search for strong gravitational lenses, in particular lensed quasars, in wide-field imaging surveys. Here, we compare the performance of three different, morphology- and photometry- based methods to find lens candidates over the Kilo-Degree Survey (KiDS) DR3 footprint (440 deg2^2). The three methods are: i) a multiplet detection in KiDS-DR3 and/or Gaia-DR1, ii) direct modeling of KiDS cutouts and iii) positional offsets between different surveys (KiDS-vs-Gaia, Gaia-vs-2MASS), with purpose-built astrometric recalibrations. The first benchmark for the methods has been set by the recovery of known lenses. We are able to recover seven out of ten known lenses and pairs of quasars observed in the KiDS DR3 footprint, or eight out of ten with improved selection criteria and looser colour pre-selection. This success rate reflects the combination of all methods together, which, taken individually, performed significantly worse (four lenses each). One movelty of our analysis is that the comparison of the performances of the different methods has revealed the pros and cons of the approaches and, most of all, the complementarities. We finally provide a list of high-grade candidates found by one or more methods, awaiting spectroscopic follow-up for confirmation. Of these, KiDS 1042+0023 is to our knowledge the first confirmed lensed quasar from KiDS, exhibiting two quasar spectra at the same source redshift at either sides of a red galaxy, with uniform flux-ratio f1.25f\approx1.25 over the wavelength range 0.45μm<λ<0.75μm.0.45\mu\mathrm{m}<\lambda<0.75\mu\mathrm{m}.Comment: 12 pages, 4 figures, 4 tables, accepted for publication in MNRA
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