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Related papers: The Pc1 geomagnetic pulsations in light of the Cep…

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In this paper we analyzed the open problems in the physics of ultra-low-frequency electromagnetic waves Pc1, which also known as the "pearls" (frequency range 0.2 -5 Hz). A number of theoretical problems arose because the standard model of…

Geophysics · Physics 2014-03-04 A. Guglielmi

Ultra-low-frequency electromagnetic waves Pc1 (0.2-5 Hz), widely known in the literature as pearls, are excited in the outer radiation belt and propagate to the Earth along the geomagnetic field lines in the form of Alfven waves. The study…

Geophysics · Physics 2026-01-06 A. V. Guglielmi , B. V. Dovbnya

We analyse photometry for 138 first overtone Cepheids from the Small Magellanic Cloud, in which Optical Gravitational Lensing Experiment (OGLE) team discovered additional variability with period shorter than first overtone period, and…

Solar and Stellar Astrophysics · Physics 2016-04-05 R. Smolec , M. Sniegowska

A theoretical investigation of the pulsation behavior of so-named ``anomalous'' Cepheids is presented. The study is based on nonlinear convective pulsation models with $Z$=0.0001 and 0.0004, mass in the range 1.3-2.2 Mo and various…

Astrophysics · Physics 2009-04-13 M. Marconi , G. Fiorentino , F. Caputo

The OGLE project led to discovery of earlier unknown forms of multiperiodic pulsation in Cepheids. Often, the observed periods may be explained in terms of simultaneous excitation of two or rarely three radial modes. However, a secondary…

Solar and Stellar Astrophysics · Physics 2012-12-06 W. A. Dziembowski

The pulsational properties of the Cepheid models along the evolutionary tracks from the Padova group (Girardi et al.), as calculated with our turbulent convective pulsation code, are in good agreement with the resonance constraints imposed…

Astrophysics · Physics 2009-11-10 J. Robert Buchler , Zoltan Kollath , Jean-Philippe Beaulieu

In this paper global surface wave modes supported by plasma discontinuities at both the magnetopause and the plasmapause are considered. The ionosphere at the ends of the magnetic field lines of the earth outer magnetosphere is considered…

Space Physics · Physics 2014-11-20 Petko Nenovski

The electromagnetic properties of subwavelength metallic surfaces are due to two kinds of elementary distinct waves, the famous surface plasmon polariton and the quasi-cylindrical wave, which are both scattered by the subwavelength…

Other Condensed Matter · Physics 2012-07-24 Philippe Lalanne , Haitao Liu

The importance of Cepheids is well known in many fields of astronomy. Section 2 introduces the Fourier decomposition, a tool to describe quantitatively the light curves of pulsating stars. Sect. 3 shows how an observational result was…

Astrophysics · Physics 2007-05-23 Ennio Poretti

With periods much longer than the duration of current pulsar timing surveys, gravitational waves in the picohertz (pHz) regime are not detectable in the typical analysis framework for pulsar timing data. However, signatures of these…

High Energy Astrophysical Phenomena · Physics 2026-02-09 Qinyuan Zheng , Chiara M. F. Mingarelli , William DeRocco , Jonathan Nay , Kimberly K. Boddy , Jeff A. Dror

The energy density of relic gravitational waves (GWs) emitted by primordial black holes (PBHs) is calculated. We estimate the intensity of GWs produced at quantum and classical scattering of PBHs, the classical graviton emission from the…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-19 Alexander D. Dolgov , Damian Ejlli

Precursors and postcursors (PPCs) are rare emission components detected in a handful of pulsars that appear beyond the main pulse emission, in some cases far away from it. In this paper we attempt to characterize the PPC emission in…

Astrophysics of Galaxies · Physics 2015-06-23 Rahul Basu , Dipanjan Mitra , Joanna M. Rankin

A hydrodynamical survey of the pulsational properties of first overtone Galactic Cepheids is presented. The goal of this study is to reproduce their observed light- and radial velocity curves. The comparison between the models and the…

Astrophysics · Physics 2009-10-31 Michael Feuchtinger , J. Robert Buchler , Zoltan Kollath

In the present paper a self-consistent theory, explaining shape of the observed phase-averaged radio spectrum in the frequency range from 100MHz to 10GHz is presented. The radio waves are assumed to be generated near the light cylinder…

High Energy Astrophysical Phenomena · Physics 2015-06-19 George Machabeli , Nino Chkheidze

We investigate the generation of gravitational waves from the rotation of an orthogonal pulsar magnetosphere in flat space time. We calculate the first order metric perturbation due to the rotation of the non-axisymmetric distribution of…

General Relativity and Quantum Cosmology · Physics 2023-12-20 Ioannis Contopoulos , Demosthenes Kazanas , Demetrios B. Papadopoulos

Soon after the discovery of radio pulsars in 1967, the pulsars are identified as strongly magnetic (typically $10^{12}$G) rapidly rotating ($\sim 10^{2}-0.1$ Hz) neutron stars. However, the mechanism of particle acceleration in the pulsar…

Astrophysics · Physics 2008-11-26 Tomohide Wada , Shinpei Shibata

As primary anchors of the distance scale, Cepheid stars play a crucial role in our understanding of the distance scale of the Universe because of their period-luminosity relation. Determining precise and consistent parameters (radius,…

The LHAASO Collaboration has observed ultrahigh-energy photons up to $1.4$PeV from $12$ $\gamma$-ray Galactic sources. In particular, the $\gamma$-ray spectra of the sources J2226+6057, J1908+0621, J1825-1326 have been published. We…

High Energy Astrophysical Phenomena · Physics 2022-09-21 Zhe Chang , Xukun Zhang , Jing-Zhi Zhou

The nature of the radio-wave radiation generated by particle cascades in both the Earth's atmosphere and dense media such as ice has, historically, been much debated. This situation changed in the early 2010's, with the community converging…

High Energy Astrophysical Phenomena · Physics 2022-01-26 Clancy W. James

Radio observations from normal pulsars indicate that the coherent radio emission is excited by curvature radiation from charge bunches. In this review we provide a systematic description of the various observational constraints on the radio…

High Energy Astrophysical Phenomena · Physics 2024-06-03 Dipanjan Mitra , Rahul Basu , George I Melikizde
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