Calculations Of Radio Emission Research Articles

Development of the radio astronomical method of cosmic particle detection for extremely high-energy cosmic ray physics and neutrino astronomy

The proposal to use ground based radio telescopes for detection of Askaryan radio pulses from particle cascades arising when extremely high-energy (EHE > 1020 eV) cosmic rays (including neutrinos) interact with the lunar regolith of multi gigaton mass was made at the end of 1980s in the framework of the Russian (Soviet) DUMAND Program. During more than a quarter of century a number of lunar experiments were carried out mainly in the 1–3 GHz frequency range using the large radio telescopes of Australia, USA, Russia and other countries but these experiments only put upper limits to the EHE cosmic rays fluxes. For this reason, it would be of great interest to search for nanosecond radio pulses from the Moon in a wider interval of frequencies (including lower ones of 100–350 MHz) with larger radio detectors – for example the giant radio telescope SKA (Square Kilometer Array) which is constructed in Australia, New Zealand and South Africa. In this paper possibilities are discussed to use one of the most sensitive meter-wavelength (∼ 110 MHz) Large Phased Array (LPA) of 187 × 384 m2 and the wide field of view meter-wavelength array of the Pushchino Radio Astronomy Observatory as prototypes of low frequency radio detectors for lunar experiments. The new scheme for fast simulation of ultrahigh and extremely high-energy cascades in dense media is also suggested. This scheme will be used later for calculations of radio emission of cascades in the lunar regolith with energies up to 1020 eV and higher in the wide frequency band of 0.1− a few GHz.

Analytic Calculation of Radio Emission from Extensive Air Showers subjected to Atmospheric Electric Fields

We have developed a code that semi-analytically calculates the radio footprint (intensity and polarization) of an extensive air shower subject to atmospheric electric fields. This can be used to reconstruct the height dependence of atmospheric electric field from the measured radio footprint. The various parameterizations of the spatial extent of the induced currents are based on the results of Monte-Carlo shower simulations. The calculated radio footprints agree well with microscopic CoREAS simulations.

Macroscopic calculation of air shower radio emission

Two patterns of calculation of radio emission from extensive air showers (EAS), the so-called microapproach and macroapproach, are considered. The predictions of these approaches are compared by calculating the spatial distribution of the 40 MHz radio emission at the EAS energy 1016 eV.

Infrared-Line Emission from Planetary Nebulae

view Abstract Citations (52) References (49) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Infrared-Line Emission from Planetary Nebulae Delmer, Thomas N. ; Gould, Robert J. ; Ramsay, William Abstract The general physical processes are considered which determine the intensities of infrared emission lines resulting from magnetic dipole transitions between fine-structure levels in certain abundant ions. Ionization equilibrium and fine-structure level population are discussed. Radiative recombination is treated in some detail in an appendix where general results are given for averaged recombination Gaunt factors and for approximate intensities of helium recombination line intensities. By means of the quantum defect method, some important collision strengths for fine structure transitions are calculated. On the basis of optical data, estimates are given of the expected infrared-line intensities from nine bright planetary nebulae. There are a number of lines from these planetaries which should have intensities in the range of 10- -16 W/cm2 and which should be observable from below the atmosphere through the 8-14- and 17-24- windows. Improved estimates are given of the expected thermal bremsstrahlung radio emission from these nebulae, with the assumption that they are optically thin to radio radiation; comparison with radio observations indicates generally satisfactory agreement with these calculations of radio emission. Publication: The Astrophysical Journal Pub Date: September 1967 DOI: 10.1086/149281 Bibcode: 1967ApJ...149..495D full text sources ADS | data products SIMBAD (9)