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The dynamic spectra of pulsars frequently exhibit diverse interference patterns, often associated with parabolic arcs in the Fourier-transformed (secondary) spectra. Our approach differs from previous ones in two ways: first, we extend…

High Energy Astrophysical Phenomena · Physics 2024-05-28 Tobias Kramer , Daniel Waltner , Eric J. Heller , Dan R. Stinebring

For a flat $\Lambda$CDM universe, the dipole of the luminosity distance can be utilized to measure the Hubble parameter. It is here shown that this is not the case in more general settings where curvature and cosmic backreaction is…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-14 S. M. Koksbang

Space-based photometry has substantially increased the number of pulsating stars found in binary systems by more than four orders of magnitude. Combined with high-resolution spectroscopy, high-precision photometry offers model-independent…

Instrumentation and Methods for Astrophysics · Physics 2025-12-18 Ema Šipková , Alex Kemp , Dario Fritzewski , Andrew Tkachenko , Dominic M. Bowman , Conny Aerts , Jasmine Vrancken

HST observations have contributed significantly to our knowledge on the behaviour of Isolated Neutron Stars (INSs) as optical emitters. First, HST has been instrumental both to discover new optical counterparts (PSR B1055-52, PSR B1929+10,…

Astrophysics · Physics 2009-09-25 P. A. Caraveo , R. P. Mignani , G. G. Pavlov , G. F. Bignami

We investigate the effects of gravitational lensing in the binary pulsar system J0737-3039. Current measurement of the orbital inclination allows the millisecond pulsar (A) to pass very close (at R_{min}=4000 km) in projection to the…

Astrophysics · Physics 2009-11-10 Dong Lai , Roman R. Rafikov

In long-baseline interferometry, bandwidth smearing of an extended source occurs at finite bandwidth when its different components produce interference packets that only partially overlap. In this case, traditional model fitting or image…

Instrumentation and Methods for Astrophysics · Physics 2013-08-07 Régis Lachaume , Jean-Philippe Berger

We have made observations of 98 low-Galactic-latitude pulsars to measure pulse broadening caused by multipath propagation through the interstellar medium. Data were collected with the 305-m Arecibo telescope at four radio frequencies…

The emission geometries, e.g. the emission region height, the beam shape, and radius-to-frequency mapping, are important predictions of pulsar radiation model. The multi-band radio observations carry such valuable information. In this…

High Energy Astrophysical Phenomena · Physics 2017-05-31 L. H. Shang , J. G. Lu , Y. J. Du , L. F. Hao , D. Li , K. J. Lee , Bin Li , L. X. Li , G. J. Qiao , Z. Q. Shen , D. H. Wang , M. Wang , X. J. Wu , Y. J. Wu , R. X. Xu , Y. L. Yue , Z. Yan , Q. J. Zhi , R. B. Zhao , R. S. Zhao

The observing signals from pulsar are always influenced by the interstellar medium (ISM) scattering. In the lower frequency observation, the intensity profiles are broadened and the plane of polarization angle (PPA) curves are flattened by…

Solar and Stellar Astrophysics · Physics 2015-06-16 Abdujappar Rusul , Ali Esamdin , Xiao-Ping Zheng , Jian-Ping Yuan

The diverse polarization properties in pulsars are in conflict with applying a unique emission mechanism to the population. The polarization position angle (PPA) traverse in most pulsars shows a S-shaped curve that can be interpreted using…

High Energy Astrophysical Phenomena · Physics 2023-03-01 Dipanjan Mitra , George I. Melikidze , Rahul Basu

Spider millisecond pulsars are, along with some eclipsing post-common envelope systems and cataclysmic variables, part of an expanding category of compact binaries with low-mass companions for which puzzling timing anomalies have been…

High Energy Astrophysical Phenomena · Physics 2019-12-10 Guillaume Voisin , René Breton , Charlotte Summers

Annual variations of interstellar scintillation can be modelled to constrain parameters of the ionized interstellar medium. If a pulsar is in a binary system, then investigating the orbital parameters is possible through analysis of the…

Radio pulsar polarization exhibits a number of complex phenomena that are classified into the realm of `beyond the rotating vector model' (RVM). It is shown that these effects can be understood in geometrical terms, as a result of coherent…

High Energy Astrophysical Phenomena · Physics 2019-06-26 J. Dyks

The ubiquitous presence of filamentary structures in the interstellar medium asks for an unbiased characterization of their properties including a stability analysis. We propose a novel technique to measure the spectrum of filaments in any…

Astrophysics of Galaxies · Physics 2018-12-19 Volker Ossenkopf-Okada , Rodion Stepanov

Previous INTEGRAL/IBIS observations have shown that the gamma-ray radiation of the Crab Nebula is highly polarised and remarkably aligned along the axis of rotation of the pulsar (Forot et al. 2008). Their study was based on the first four…

High Energy Astrophysical Phenomena · Physics 2013-02-18 Paul Moran , Andy Shearer , Christian Gouiffes , Philippe Laurent

The paper presents the timing and spectral analysis of several observations of the Crab pulsar performed with INTEGRAL in the energy range 3-500 keV. All these observations, when summed together provide a high statistics data set which can…

Astrophysics · Physics 2009-11-11 T. Mineo , C. Ferrigno , L. Foschini , A. Segreto , G. Cusumano , G. Malaguti , G. Di Cocco , C. Labanti

Precision measurements are reported of the cross-spectrum of rotationally-induced differential position displacements in a pair of colocated 39 m long, high power Michelson interferometers. One arm of each interferometer is bent…

This paper indicates that the sensitivity and accuracy of an infrared radiometer for emissivity measurements depends not only on its design and the measurement method, but also on the spurious radiation. This spurious radiation must be…

We discuss how the curvature of the universe can be robustly measured employing only the gross features of the CMB anisotropy spectrum. Though the position of the first peak is not robust, uncertainties in the model for structure formation…

Astrophysics · Physics 2007-05-23 Wayne Hu , Martin White

Just as the ordinary Doppler effect serves as a tool to measure radial velocities of celestial objects, so can the relativistic Doppler effect be implemented to measure a combination of radial and transverse velocities by using recent…

Astrophysics · Physics 2016-01-13 Leonid M. Ozernoy