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Start Over Language Czech Subject astrophysics Type model:article

62. Potentials separable in addition for Chandrasekhar models with axial symmetry

Creator:
Sanz Subirana, Juame and Juan Zornoza, J. Miguel
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
astrophysics, Chandrasekhar models, and axial symmetry
Language:
Czech
Description:
In this work, the potential for a non-stationary stellar system is determinated, under the hypothesis of separability, for a stelar model that verifies the Chandrasekhar postulates, with axial symmetry (non-cylindrical), and with an equatorial plane of symmetry. The obtained results generalize those of the cylindrical case. As in the cylindrical case, it appears a term which can be interpreted as a contribution due to the galactic halo. It also appears - as in the cylindrical case - a term proportional to although its cofficient of proporcionality is now a function of the θ angle and show a singular behavior. Finally, a term due to the non inertiality of the galactic plane, regarded as the plane of symmetry of the stellar system, is obtained.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

63. Projevy kosmologické konstanty v astrofyzice

Creator:
Stuchlík, Zdeněk, Slaný, Petr, and Kovář, Jiří
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
kosmologická konstanta, astrofyzika, cosmological constant, astrophysics, 6, and 53
Language:
Czech and English
Description:
Pestrá škála kosmologických testů ukazuje, že různé vlastnosti našeho vesmíru lze přesvědčivě vysvětlit, pokud je dominantní složkou jeho současného energetického obsahu rovnoměrně rozptýlená substance, jež dostala název temná energie. Jejím základním rysem je kosmická repulze způsobující zrychlené rozpínání prostoru, přičemž hustota temné energie zůstává neměnná; v Einsteinových rovnicích pole ji velmi dobře reprezentuje kosmologická konstanta Λ. Přirozeně, kosmologická konstanta se musí projevovat nejen v evoluci vesmíru, ale též v astrofyzikálních procesech. Představíme některé její astrofyzikální projevy studované opavskou relativistickou skupinou - vliv na pohyb hvězd v gravitačním poli supermasivních černých děr, na pohyb trpasličích galaxií na periferii obřích galaxií, na tvar a vlastnosti toroidálních konfigurací hmoty obíhajících supermasivní černé díry nebo sférických polytropických konfigurací modelujících hala temné hmoty., A wide range of cosmological tests indicates that various properties of the Universe can be well explained by the presence of a uniformly dispersed dominant part of the current energetic content, i.e. so-called dark energy. Its basic feature is expressed by cosmic repulsion, causing an accelerated expansion of space, whereas the density of dark energy remains unchanged; in Einstein field equations, dark energy is well described by the cosmological constant (Λ). Clearly Λ must be defined not only in Universe evolution, but also in astrophysical processes. Here we introduce some of the astrophysical phenomena of Λ studied by the relativistic group in Opava, e.g. its influence on the motion of stars in the gravitational field of supermassive black holes, on the motion of dwarf galaxies at the peripheries of giant galaxies, on the form and properties of toroidal configurations of fluid circling around supermassive black holes, or on polytrophic configurations modelling dark matter halos., Zdeněk Stuchlík, Petr Slaný, Jiří Kovář., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

64. Radial pulsations and vibrational instability of massive stars

Creator:
Kirbiyik, Halil
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
astrophysics, massive stars, and radial pulsation
Language:
Czech
Description:
By taking some evolutionary models of an initially 60 M⊙-star, their radial vibrational stabilities have been investigated. These models, evolving with mass loss, are in the advanced stages of their evolution, and burn He in their cores. Calculations have been performed for the first and second harmonics as well as for the fundemental mode; and some of these models were found to be vibrationally unstable in the fundemental mode.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

65. Radio wave diagnostics of solar active regions: Part I - mm-cm bands, Part II - dm-m bands

Creator:
Karlický, M. and Krüger, A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
astrophysics, solar active regions, and radio spectral observations
Language:
Czech
Description:
Part I of this review considers the outcome of different methods of observation of active regions at mm- and cm-v/aves exploring the source structures and parameters in the chromosphere and corona. Calculations of emission models invoking bremsstrahlung and gyromagnetic radiation are summarlzed applying for a great variety of physical conditions. Diagnostic capacities of different kinds of microwave burst emission are briefly taken into account. Part II of the review considers the dm- and m-radio spectral observations as diagnostic tool for the determination of plasma parameters in the coronal parts of solar active regions. The main attention is devoted to the radio diagnoetics of solar flares. The most important types of dm- and m-radio bursts are presented. the latest theoretical and observational results summarized and their diagnostic aapects briefly discussed.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

66. Raketoplány a jejich přínos pro astrofyziku

Creator:
František Fárník
Format:
print
Type:
article, články, model:article, and TEXT
Subject:
Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce, raketoplány, astrofyzika, spaceplanes, astrophysics, 12, and 00
Language:
Czech
Description:
Another article in this issue, Space Shuttles and their contribution, provides an overview of the Space Shuttle Program (officially called Space Transportation System - STS), which the U.S. established in the late 1960s. The program commenced on April 12, 1981, with the launching of Columbia STS-1 - the first shuttle orbital flight - and concluded with its last mission, STS-135 flown by Atlantis in July 2011, which retired the final shuttle in the fleet. The Space Shuttle program formally ended on August 31, 2011. and František Fárník.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

69. Rentgenová astrofyzika a robotické dalekohledy

Creator:
Blažek, Martin
Format:
print
Type:
article, zprávy, model:article, and TEXT
Subject:
Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce, astrofyzika, konference, astrophysics, conferences, 12, and 00
Language:
Czech
Description:
8th INTEGRAL/BART Workshop was organised by the Astronomical Institute of the ASCR at Karlovy Vary on April 26-29, 2011. The workshop focused on relevant international collaborations in the field of high-energy astrophysics with emphasis on satellite projects and ground-based experiments. and Martin Blažek.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

70. Roboti a družice

Creator:
Blažek, Martin
Type:
article, zprávy, model:article, and TEXT
Subject:
Teoretická astronomie. Nebeská mechanika, kongresy, astrofyzika, umělé družice, dalekohledy, congresses, astrophysics, artificial satellites, telescopes, 6, and 521
Language:
Czech
Description:
7th INTEGRAL/BART Workshop was organised by the Astronomical Institute of the ASCR at Karlovy Vary on April 14-18, 2010. The workshop focused on work performed at the Group of High Energy Astrophysics in Ondřejov (and collaborating Institutes such as CTU and students) and relevant international collaborations in the field of high-energy astrophysics with emphasis on satellite projects and ground-based experiments. and Martin Blažek.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public