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200 papers

We introduce a novel framework that incorporates multiple scattering for large-scale 3D particle-localization using single-shot in-line holography. Traditional holographic techniques rely on single-scattering models which become inaccurate…

Signal Processing · Electrical Eng. & Systems 2019-06-19 Waleed Tahir , Ulugbek S. Kamilov , Lei Tian

We use the Five-hundred-meter Aperture Spherical radio Telescope to observe the bright millisecond pulsar PSR B1937+21 (J1939+2134) and record the data in the band from 1.0 to 1.5 GHz. We measure the neutral hydrogen (HI) emission and…

High Energy Astrophysical Phenomena · Physics 2025-07-31 Jinchen Jiang , Shunshun Cao , Kejia Lee , Bojun Wang , Heng Xu , Siyuan Chen , Yanjun Guo , Peng Jiang , Weicong Jing , Jiguang Lu , Jiangwei Xu , Renxin Xu , Zihan Xue

It is demonstrated that an object distribution can be successfully retrieved from its diffraction pattern or hologram, even if some of the measured intensity samples are missing. The maximum allowable number of missing values depends on the…

Image and Video Processing · Electrical Eng. & Systems 2019-08-28 Tatiana Latychevskaia

We use a publicly available numerical wave-propagation simulation of Hartlep et al. 2011 to test the ability of helioseismic holography to detect signatures of a compact, fully submerged, 5% sound-speed perturbation placed at a depth of 50…

Solar and Stellar Astrophysics · Physics 2015-06-11 Douglas C. Braun

A joint action of depth and bandwidth depolarization in the interstellar medium is considered using a model of N homogeneous synchrotron layers with Faraday rotation. The bandwidth depolarization can be used in multifrequency polarimetric…

Astrophysics · Physics 2007-05-23 E. N. Vinyajkin

Protonated molecular species have been proven to be abundant in the interstellar gas. This class of molecules is also pivotal for the determination of important physical parameters for the ISM evolution (e.g. gas ionisation fraction) or as…

Radio pulsars allow the study of the ionised interstellar medium and its dispersive effects, a major noise source in gravitational wave searches using pulsars. In this paper, we compare the functionality and reliability of three commonly…

High-precision timing of millisecond pulsars (MSPs) over years to decades is a promising technique for direct detection of gravitational waves at nanohertz frequencies. Time-variable, multi-path scattering in the interstellar medium is a…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Anne M. Archibald , Vladislav I. Kondratiev , Jason W. T. Hessels , Daniel R. Stinebring

The presence of a scattering medium in the imaging path between an object and an observer is known to severely limit the visual acuity of the imaging system. We present an approach to circumvent the deleterious effects of scattering, by…

As one of the major components of the interstellar medium, the ionized gas in our Milky Way, especially the low-density diffuse component, has not been extensively observed in the radio band. The Galactic Plane Pulsar Snapshot (GPPS) survey…

Astrophysics of Galaxies · Physics 2022-12-01 L. G. Hou , J. L. Han , Tao Hong , X. Y. Gao , Chen Wang

Since 2013 round-the-clock monitoring of the sky is carried out simultaneously in 96 space beams using the high-sensitivity radio telescope of LPA (Large Phased Array) at the frequency 110.25 MHz. These observations are made under the…

High Energy Astrophysical Phenomena · Physics 2018-08-15 V. M. Malofeev , S. A. Tyul'bashev

Pulsating subdwarf B stars oscillate in short-period $p$-modes or long-period $g$-modes. HS 0702 + 6043 is one of currently three objects known to show characteristics of both types and hence is classified as hybrid pulsator. We briefly…

Astrophysics · Physics 2008-12-31 R. Lutz , S. Schuh , R. Silvotti , R. Kruspe , S. Dreizler

We present new periodograms that are effective in distinguishing Doppler shift from spectral shape variability in astronomical spectra. These periodograms, building upon the concept of partial distance correlation, separate the periodic…

Instrumentation and Methods for Astrophysics · Physics 2022-04-06 Avraham Binnenfeld , Sahar Shahaf , Richard I. Anderson , Shay Zucker

One of the major challenges for pulsar timing array (PTA) experiments is the mitigation of the effects of the turbulent interstellar medium (ISM) from timing data. These can potentially lead to measurable delays and/or distortions in the…

Pulsating stars in eclipsing binary systems are powerful tools to test stellar models. Binarity enables to constrain the pulsating component physical parameters, whose knowledge drastically improves the input physics for asteroseismic…

Solar and Stellar Astrophysics · Physics 2015-06-12 C. Maceroni , J. Montalbán , D. Gandolfi , K. Pavlovski , M. Rainer

Radio emission has been detected from all the stages of stellar evolution across the HR Diagram. Its presence reveals both astrophysical phenomena and stellar activity which, otherwise, would not be detectable by other means. The…

Astrophysics · Physics 2009-11-10 Josep M. Paredes

By a proper arrangement of a digital holography setup, that combines off-axis geometry with phase-shifting recording conditions, it is possible to reach the theoretical shot noise limit, in real-time experiments.We studied this limit, and…

Optics · Physics 2012-06-11 Frédéric Verpillat , Fadwa Joud , Michael Atlan , Michel Gross

We conduct a small-scale pathfinding survey designed to identify the average polarization properties of the diffuse ISM locally at the lowest dust content regions. We perform deep optopolarimetric surveys within three $\sim 15' \times 15'$…

Astrophysics of Galaxies · Physics 2018-08-15 R. Skalidis , G. V. Panopoulou , K. Tassis , V. Pavlidou , D. Blinov , I. Komis , I. Liodakis

Observations of pulsar scintillation are among the few astrophysical probes of very small-scale ($\lesssim$ au) phenomena in the interstellar medium (ISM). In particular, characterization of scintillation arcs, including their curvature and…

High Energy Astrophysical Phenomena · Physics 2023-11-28 S. K. Ocker , J. M. Cordes , S. Chatterjee , D. R. Stinebring , T. Dolch , V. Pelgrims , J. W. McKee , C. Giannakopoulos , D. J. Reardon

This review describes the observational properties of radio pulsars, fast rotating neutron stars, emitting radio waves. After the introduction we give a list of milestones in pulsar research. The following chapters concentrate on pulsar…

High Energy Physics - Phenomenology · Physics 2009-09-29 John H. Seiradakis , Richard Wielebinski
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