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Related papers: Redeveloping a CLEAN Deconvolution Algorithm for S…

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In axion models, interactions between axions and electromagnetic waves induce frequency-dependent time delays determined by the axion mass and decay constant. These small delays are difficult to detect, limiting the effectiveness of…

High Energy Astrophysical Phenomena · Physics 2025-10-29 Haihao Shi , Zhenyang Huang , Qiyu Yan , Jun Li , Guoliang Lü , Xuefei Chen

Deconvolution is essential for radio interferometric imaging to produce scientific quality data because of finite sampling in the Fourier plane. Most deconvolution algorithms are based on CLEAN which uses a grid of image pixels, or clean…

Instrumentation and Methods for Astrophysics · Physics 2016-11-18 Sarod Yatawatta

Free electrons in the ionosphere lead to significant group delay dispersion for signals in the megahertz and low gigahertz range. A novel microwave filter is presented that is capable of compensating for the non-linear ionospheric…

Instrumentation and Methods for Astrophysics · Physics 2013-05-03 Paul Roberts

Radio emission propagating over an Earth-pulsar line of sight provides a unique probe of the intervening ionized interstellar medium (ISM). Variations in the integrated electron column density along this line of sight, or dispersion measure…

High Energy Astrophysical Phenomena · Physics 2020-04-08 M. T. Lam , T. J. W. Lazio , T. Dolch , M. L. Jones , M. A. McLaughlin , D. R. Stinebring , M. Surnis

Qiao and his collaborators recently proposed an inverse Compton Scattering (ICS) model to explain radio emission of pulsars. In this paper, we investigate the polarization properties of pulsar emission in the model. First of all, using the…

Astrophysics · Physics 2009-10-31 R. X. Xu , J. F. Liu , J. L. Han , G. J. Qiao

Future high spectral resolution telescopes will enable us to place tight constraints on turbulence in the intra-cluster medium through the line widths of strong emission lines. At the same time, these bright lines are the most prone to be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Cien Shang , S. Peng Oh

Dispersion scan is a self-referenced measurement technique for ultrashort pulses. Similar to frequency-resolved optical gating, the dispersion scan technique records the dependence of nonlinearly generated spectra as a function of a…

Instrumentation and Detectors · Physics 2018-02-14 Esmerando Escoto , Tamas Nagy , Ayhan Tajalli , Günter Steinmeyer

A point-spread function describes the optics of an imaging system and can be used to correct collected images for instrumental effects. The state of the art for deconvolving images with the point-spread function is the Richardson-Lucy…

Instrumentation and Methods for Astrophysics · Physics 2024-05-07 Stefan Johann Hofmeister

We observed the scintillation pattern of nine bright pulsars at 324 MHz and three at 1.68 GHz and analyzed the wavenumber spectrum which is related to electron density variations of the plasma turbulence of the interstellar medium. For all…

Astrophysics of Galaxies · Physics 2022-12-21 N. Bartel , M. S. Burgin , E. N. Fadeev , M. V. Popov , N. Ronaghikhameneh , T. V. Smirnova , V. A. Soglasnov

Humans will launch spacecraft that travel at an appreciable fraction of the speed of light. Spacecraft traffic will be tracked by radar. Scattering of pulsed electromagnetic fields by an object in uniform translational motion at…

Fast radio bursts are radio transients observed mainly around 1.5 GHz. Their peak frequency decreases at a rate of 100 ~ 500 MHz/s and some of them have a broader pulse with an exponentially decaying tail. Common assumptions for fast radio…

High Energy Astrophysical Phenomena · Physics 2017-08-30 Qiwu Song , Yu Huang , Hengqiang Feng , Lei Yang , Tuanhui Zhou , Qingyu Luo , Tengfei Song , Xuefei Zhang , Yu Liu , Guangli Huang

The possibility of a polarization sounding of the pulsar magnetosphere is examined, using intrinsic pulsar emission as a probe signal, for modern radio telescopes operating in the meter and decameter wavelength range. Different models of…

Astrophysics of Galaxies · Physics 2015-06-11 O. M. Ulyanov , A. I. Shevtsova , A. A. Seredkina

Effect of the induced Compton and Raman scattering on short, bright radio pulses is investigated. It is shown that when a single pulse propagates through the scattering medium, the effective optical depth is determined by the duration of…

Astrophysics · Physics 2009-11-13 Yuri Lyubarsky

Pulsar radio emission and its polarization are observed to evolve with frequency. This frequency dependence is key to the emission mechanism and the structure of the radio beam. With the new Ultra-Wideband receiver (UWL) on the Parkes radio…

High Energy Astrophysical Phenomena · Physics 2020-06-17 Lucy Oswald , Aris Karastergiou , Simon Johnston

In 2004, McLaughlin et al. discovered a phenomenon in the radio emission of PSR J0737-3039B (B) that resembles drifting sub-pulses. The repeat rate of the sub-pulses is equal to the spin frequency of PSR J0737-3039A (A); this led to the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 P. C. C. Freire , N. Wex , M. Kramer , D. R. Lorimer , M. A. McLaughlin , I. H. Stairs , R. Rosen , A. G. Lyne

In a cycle of papers, starting with the present one, a fundamental possibility of the polarization sounding of a pulsar magnetosphere using pulsar self-radiation as a test signal will be considered. The main idea of such a sounding is based…

Astrophysics of Galaxies · Physics 2014-11-25 O. M. Ulyanov , A. I. Shevtsova , A. O. Skoryk

The frequency dependence of radio pulse arrival times provides a probe of structures in the intervening media. Demorest et al. 2013 was the first to show a short-term (~100-200 days) reduction in the electron content along the line of sight…

This paper provides an analysis of radio wave scattering for frequencies ranging from the microwave to the Terahertz band (e.g., 1 GHz - 1 THz), by studying the scattering power reradiated from various types of materials with different…

Ultrasound is widely used in medical diagnostics allowing for accessible and powerful imaging but suffers from resolution limitations due to diffraction and the finite aperture of the imaging system, which restricts diagnostic use. The…

Computer Vision and Pattern Recognition · Computer Science 2024-08-08 Felix Duelmer , Walter Simson , Mohammad Farid Azampour , Magdalena Wysocki , Angelos Karlas , Nassir Navab

Fast radio bursts (FRBs) are millisecond-timescale radio transients, the origins of which are predominantly extragalactic and likely involve highly magnetized compact objects. FRBs undergo multipath propagation, or scattering, from electron…

High Energy Astrophysical Phenomena · Physics 2022-12-14 S. K. Ocker , J. M. Cordes , S. Chatterjee , D. Li , C. H. Niu , J. W. McKee , C. J. Law , R. Anna-Thomas