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Many models for the pulsar radio and $\gamma$-ray emissions have been developed. The tests for these models using observational data are very important. Tests for the pulsar radio emission models using frequency-altitude relation are…

Astrophysics · Physics 2008-11-26 G. J. Qiao , K. J. Lee , H. G. Wang , R. X. Xu , B. Zhang

Measurements of the polarization of radio emission are subject to a number of depolarization effects such as bandwidth depolarization, which is caused by the averaging effect of a finite channel bandwidth combined with the…

Instrumentation and Methods for Astrophysics · Physics 2023-02-08 Maxwell A. Fine , Cameron L. Van Eck , Luke Pratley

We have embarked on a survey for pulsars and fast transients using the 13-beam Multibeam receiver on the Parkes radio telescope. Installation of a digital backend allows us to record 400 MHz of bandwidth for each beam, split into 1024…

Polarization of electromagnetic waves carries a large amount of information about their astrophysical emitters and the media they passed through, and hence is crucial in various aspects of astronomy. Here we demonstrate an important but…

High Energy Astrophysical Phenomena · Physics 2024-09-20 Ze-Lin Zhang , Ruo-Yu Liu

In this paper the anomalous intense pulse of the PSR J0953+0755 was studied in decametre wavelength range. For this pulse two scales of fine structure were discovered. The long-scale structure consists of four components, where the visible…

High Energy Astrophysical Phenomena · Physics 2015-11-11 O. M. Ulyanov , A. O. Skoryk , A. I. Shevtsova , M. S. Plakhov , O. O. Ulyanova

We develop the theory of interstellar scintillation as caused by an irregular plasma having a power-law spatial density spectrum with a spectral exponent of 4 corresponding to a medium with abrupt changes in its density. An ``outer scale''…

Astrophysics · Physics 2009-10-31 Hendrik Lambert , Barney Rickett

A search for pulse signals was carried out in a new sky area included in the monitoring program for the search for pulsars and transients. Processing of several months data recorded in six frequency channels with a total bandwidth of 2.5…

High Energy Astrophysical Phenomena · Physics 2022-07-20 V. A. Samodurov , S. A. Tyul'bashev , M. O. Toropov , S. V. Logvinenko

In this paper we present a blind deconvolution scheme based on statistical wavelet estimation. We assume no prior knowledge of the wavelet, and do not select a reflector from the signal. Instead, the wavelet (ultrasound pulse) is…

Other Computer Science · Computer Science 2015-06-01 Roberto H. Herrera , Zhaorui Liu , Natasha Raffa , Paul Christensen , Adrianus Elvers

In binary radio pulsar system J0737-3039, slow pulsar B shows orbital modulations of intensity, being especially bright at two short orbital phases. We propose that these modulations are due to distortion of pulsar B magnetosphere by pulsar…

Astrophysics · Physics 2009-11-10 Maxim Lyutikov

A variety of pulsar studies, ranging from high precision astrometry to tests for theories of gravity, require high time resolution data. Few such observations at more than two frequencies below 1 GHz are available. Giant Meterwave Radio…

Astrophysics · Physics 2007-05-23 Bhal Chandra Joshi , Sunil Ramakrishna

We investigate, through simulation, the evolution of polarization states during atmospheric propagation of high power, ultrashort laser pulses. A delayed rotational response model handling arbitrary, transverse polarization couples both the…

Optics · Physics 2015-06-16 J. P. Palastro

Spatial resolution improvement from an acquired measurement using long pulse is developed for Brillouin optical time domain analysis (BOTDA) systems based on the total variation deconvolution algorithm. The frequency dependency of Brillouin…

Signal Processing · Electrical Eng. & Systems 2021-04-07 Li Shen , Zhiyong Zhao , Can Zhao , Hao Wu , Chao Lu , Ming Tang

Established image recovery methods in fast ultrasound imaging, e.g. delay-and-sum, trade the image quality for the high frame rate. Cutting-edge inverse scattering methods based on compressed sensing (CS) disrupt this tradeoff via a priori…

Medical Physics · Physics 2019-03-15 Martin F. Schiffner

Freely oriented small anisotropic grains and molecules depolarize radiation both in single scattering and in the process of multiple scattering. Especially large depolarization occurs for resonant scattering corresponding to the electron…

Solar and Stellar Astrophysics · Physics 2015-06-17 N. A. Silant'ev , G. A. Alekseeva , V. V. Novikov

Timing pulses of pulsars has proved to be a most powerful technique useful to a host of research areas in astronomy and physics. Importantly, the precision of this timing is not only affected by radiometer noise, but also by intrinsic pulse…

High Energy Astrophysical Phenomena · Physics 2015-05-28 K. Liu , J. P. W. Verbiest , M. Kramer , B. W. Stappers , W. van Straten , J. M. Cordes

Pulsars are the fast rotating neutron stars with strong magnetic field, that emit over a wide frequency range. In spite of the efforts during 40 years after the discovery of pulsars, the mechanism of their radio emission remains to be…

Solar and Stellar Astrophysics · Physics 2015-03-19 V. M. Kontorovich , A. B. Flanchik

Decades of work on beam deformation on reflection, and especially on lateral shifts, have spread the idea that a reflected beam is larger than the incident beam. However, when the right conditions are met, a beam reflected by a multilayered…

We develop a novel algorithm for large-scale holographic reconstruction of 3D particle fields. Our method is based on a multiple-scattering beam propagation method (BPM) combined with sparse regularization that enables recovering dense 3D…

Optics · Physics 2021-05-24 Hao Wang , Waleed Tahir , Jiabei Zhu , Lei Tian

Identification of time-varying linear systems, which introduce both time-shifts (delays) and frequency-shifts (Doppler-shifts), is a central task in many engineering applications. This paper studies the problem of identification of…

Information Theory · Computer Science 2018-03-06 Waheed U. Bajwa , Kfir Gedalyahu , Yonina C. Eldar

Interstellar scintillation analysis of pulsars allows us to probe the small-scale distribution and inhomogeneities of the ionized interstellar medium. Our priority is to present the data set and the basic measurements of scintillation…

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