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Related papers: Interstellar Holography

200 papers

In a previous paper, we discussed an original solution to improve the performances of coronagraphs by adding, in the optical scheme, an adaptive hologram removing most of the residual speckle starlight. In our simulations, the detection…

Instrumentation and Methods for Astrophysics · Physics 2011-02-17 Davide Ricci , Hervé Le Coroller , Antoine Labeyrie , Pierre Piron

The ionospheric scattering of pulses emitted by PSR B0950+08 is measured using the 10-m RadioAstron Space Radio Telescope, the 300-m Arecibo Radio Telescope and the 14x25-m Westerbork Synthesis Radio Telescope (WSRT) at a frequency band…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 V. I. Zhuravlev , Yu. I. Yermolaev , A. S. Andrianov

Discoverable interstellar communication signals are expected to exhibit al least one signal characteristic clearly distinct from random noise. A hypothesis is proposed that radio telescope received signals may contain transmitted delta-t…

Signal Processing · Electrical Eng. & Systems 2022-02-28 William J. Crilly

Context. The spatially coherent multipath propagation of pulsar radiation leads to a temporal and spectral interference patterns called scintillation. It is caused by density variations in the ionized interstellar medium, which often take…

High Energy Astrophysical Phenomena · Physics 2026-05-15 Tim Sprenger , Xun Shi , Olaf Wucknitz , Robert A. Main

Pulsars are the only cosmic radio sources known to be sufficiently compact to show diffractive interstellar scintillations. Images of the variance of radio signals in both time and frequency can be used to detect pulsars in large-scale…

Instrumentation and Methods for Astrophysics · Physics 2016-08-17 S. Dai , S. Johnston , M. E. Bell , W. A. Coles , G. Hobbs , R. D. Ekers , E. Lenc

We have examined data from pulsars B0950+08 and B0329+54 for evidence of temporally coherent radiation using the modified coherence function (MCF) technique of Jenet et al. (2001). We consider the influence of both instrumental bandpass and…

Astrophysics · Physics 2009-11-07 J. M. Smits , B. W. Stappers , J-P. Macquart , R. Ramachandran , J. Kuijpers

Long-term studies of binary millisecond pulsars (MSPs) provide precise tests of strong-field gravity and can be used to measure neutron-star masses. PSR~J1909$-$3744, a binary MSP has been the subject of several pulsar timing analyses. The…

High Energy Astrophysical Phenomena · Physics 2022-11-09 Jacob Askew , Daniel Reardon , Ryan Shannon

Cosmic ray electrons and positrons are tracers of particle propagation in the interstellar medium (ISM). A recent measurement performed using H.E.S.S. extends the all-electron (electron+positron) spectrum up to 20TeV, probing very local…

High Energy Astrophysical Phenomena · Physics 2019-01-08 R. López-Coto , R. D. Parsons , J. A. Hinton , G. Giacinti

B-type stars are promising targets for asteroseismic modelling, since their frequency spectrum is relatively simple. We deduce and summarise observational constraints for the hybrid pulsator, HD50230, earlier reported to have deviations…

Radio telescopes are used to accurately measure the time of arrival (ToA) of radio pulses in pulsar timing experiments that target mostly millisecond pulsars (MSPs) due to their high rotational stability. This allows for detailed study of…

Instrumentation and Methods for Astrophysics · Physics 2015-09-09 Griffin Foster , Aris Karastergiou , Remi Paulin , Tobia Carozzi , Simon Johnston , Willem van Straten

Recent technological advances could make interstellar travel possible, using ultra-lightweight sails pushed by lasers or solar photon pressure, at speeds of a few percent the speed of light. Obtaining remote observational data from such…

Instrumentation and Methods for Astrophysics · Physics 2017-11-17 Michael Hippke

Holographic representations of data encode information in packets of equal importance that enable progressive recovery. The quality of recovered data improves as more and more packets become available. This progressive recovery of the…

Information Theory · Computer Science 2021-03-01 Alfred Marcel Bruckstein , Martianus Frederic Ezerman , Adamas Aqsa Fahreza , San Ling

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

Holographic MIMO is a spatially-constrained MIMO system with a massive number of antennas, possibly thought of, in its ultimate form, as a spatially-continuous electromagnetic aperture. Accurate and tractable channel modeling is critical to…

Information Theory · Computer Science 2020-12-15 Andrea Pizzo , Thomas Marzetta , Luca Sanguinetti

The interference of the directly emitted photoelectron wave and the wave scattered coherently by neighboring atoms gives holographic fringes in the photoelectron emission intensity $I(\hat{\bf R})$. In the electron emission holography…

Condensed Matter · Physics 2016-08-31 Eddy Timmermans , G. T. Trammell , J. P. Hannon

We have explored the optimal frequency of interstellar photon communications and benchmarked other particles as information carriers in previous papers of this series. We now compare the latency and bandwidth of sending probes with…

Instrumentation and Methods for Astrophysics · Physics 2018-05-22 Michael Hippke , Paul Leyland , John G. Learned

Prior work using synchronized, geographically spaced radio telescopes, and a radio interferometer, suggests that narrow-bandwidth polarized pulse pair measurements repeatedly falsify a noise-cause hypothesis, given a prior celestial…

Signal Processing · Electrical Eng. & Systems 2024-12-10 William J. Crilly

In this paper we present recent Low Frequency Array (LOFAR) observations of the pulsar J1740+1000. We confirm that its spectrum has a turnover at 260 MHz, which is unusual for a typical pulsar. We argue that in this case interferometric…

High Energy Astrophysical Phenomena · Physics 2021-04-02 K. Rozko , J. Kijak , K. Chyzy , W. Lewandowski , T. Shimwell , S. S. Sridhar , M. Curylo , A. Krankowski , L. Blaszkiewicz

Interstellar radio wave scattering leads to flux density fluctuations and pulse broadening of pulsar signals. However, Galactic distribution and the structure of the scattering medium are still poorly understood. Pulsar pulse broadening…

Astrophysics of Galaxies · Physics 2023-12-19 Qiuyi He , Xun Shi

An observer, situated several thousand light-years away from a radio pulsar, finds himself embedded in the diffraction pattern resulting from the propagation of the radio waves through the irregular interstellar medium. The observer's…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Redouane Fakir