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Related papers: Flicker noise pulsar radio spectra

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This thesis focuses on the study of binary radio pulsars, their evolution and some specific use of their properties to investigate fundamental physics such as general relativity and other gravitational theories. The work that we present…

Solar and Stellar Astrophysics · Physics 2009-07-16 Rene P. Breton

Amplification is usually necessary when measuring the frequency instability of microwave signals. In this work, we develop a flicker noise free frequency measurement system based on a common or shared amplifier. First, we show that…

Instrumentation and Detectors · Physics 2012-02-23 Daniel L. Creedon , Michael E. Tobar , Eugene N. Ivanov , John G. Hartnett

We present a census of 100 pulsars, the largest below 100 MHz, including 94 normal pulsars and six millisecond pulsars, with the Long Wavelength Array (LWA). Pulse profiles are detected across a range of frequencies from 26 to 88 MHz,…

High Energy Astrophysical Phenomena · Physics 2025-03-31 Pratik Kumar , Greg B. Taylor , Kevin Stovall , Jayce Dowell , Stephen M. White

The recent massive measurements of pulsar frequency second derivatives have shown that they are 100-1000 times larger than expected for standard pulsar slowdown low. Moreover, the second derivatives as well as braking indices are even…

Astrophysics · Physics 2007-05-23 G. Beskin , A. Biryukov , S. Karpov

We report on X-ray and gamma-ray observations of the millisecond pulsar B1937+21 taken with the Chandra X-ray Observatory, XMM-Newton, and the Fermi Large Area Telescope. The pulsar X-ray emission shows a purely non-thermal spectrum with a…

High Energy Astrophysical Phenomena · Physics 2015-06-19 C. -Y. Ng , J. Takata , G. C. K. Leung , K. S. Cheng , P. Philippopoulos

Continuous gravitational waves from neutron stars could provide an invaluable resource to learn about their interior physics. A common search method involves matched filtering a modeled template against the noisy gravitational-wave data to…

General Relativity and Quantum Cosmology · Physics 2017-09-26 Gregory Ashton , Reinhard Prix , David Ian Jones

The X-ray and gamma-ray spectrum of rotation-powered millisecond pulsars is investigated in a model for acceleration and pair cascades on open field lines above the polar caps. Although these pulsars have low surface magnetic fields, their…

Astrophysics · Physics 2016-08-30 Alice K. Harding , Vladimir V. Usov , Alex G. Muslimov

Using archival as well as freshly acquired data, we assess the X-ray behaviour of the Fermi/LAT gamma-ray pulsars listed in the First Fermi source catalog. After revisiting the relationships between the pulsars' rotational energy losses and…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Martino Marelli , Andrea De Luca , Patrizia A. Caraveo

We present first results from a LOFAR census of non-recycled pulsars. The census includes almost all such pulsars known (194 sources) at declinations ${\rm Dec}> 8^\circ$ and Galactic latitudes $|{\rm Gb}| > 3^\circ$, regardless of their…

The phenomenon of pulsar nulling, observed as the temporary inactivity of a pulsar, remains poorly understood both observationally and theoretically. Most observational studies that quantify nulling employ a variant of Ritchings (1976)'s…

High Energy Astrophysical Phenomena · Physics 2023-09-15 Akash Anumarlapudi , Joseph K. Swiggum , David L. Kaplan , Travis D. J. Fichtenbauer

The Parkes telescope has been monitoring 286 radio pulsars approximately monthly since 2007 at an observing frequency of 1.4 GHz. The wide dispersion measure (DM) range of the pulsar sample and the uniformity of the observing procedure make…

High Energy Astrophysical Phenomena · Physics 2021-01-06 H. Kumamoto , S. Dai , S. Johnston , M. Kerr , R. M. Shannon , P. Weltevrede , C. Sobey , R. N. Manchester , G. Hobbs , K. Takahashi

The observed spectra of 9 pulsars for which multiwavelength data are available from radio to $X$- or $\gamma$-ray bands (Crab, Vela, Geminga, B0656+14, B1055-52, B1509-58, B1706-44, B1929+10, and B1951+32) are compared with the spectrum of…

Astrophysics of Galaxies · Physics 2009-08-11 H. Ardavan , A. Ardavan , J. Singleton , J. Fasel , W. Junor , J. Middleditch , M. R. Perez , A. Schmidt , P. Sengupta , P. Volegov

Frequency metrology outperforms any other branch of metrology in accuracy (parts in $10^{-16}$) and small fluctuations ($<10^{-17}$). In turn, among celestial bodies, the rotation speed of millisecond pulsars (MSP) is by far the most stable…

Data Analysis, Statistics and Probability · Physics 2022-02-04 Siyuan Chen , Francois Vernotte , Enrico Rubiola

We report on a likelihood stacking search for gamma-ray pulsars at 362 high-latitude locations that coincide with known radio pulsar positions. We observe a stacked signal conservatively 2.5$\sigma$ over the background. Stacking their…

High Energy Astrophysical Phenomena · Physics 2023-08-04 Yuzhe Song , Timothy A. D. Paglione , Joshua Tan , Charles Lee-Georgescu , Danisbel Herrera

Pulse-to-pulse profile shape variations introduce correlations in pulsar times of arrival (TOAs) across radio frequency measured at the same observational epoch. This leads to a broadband noise in excess of radiometer noise, which is termed…

High Energy Astrophysical Phenomena · Physics 2024-01-10 A. D. Kulkarni , R. M. Shannon , D. J. Reardon , M. T. Miles , M. Bailes , M. Shamohammadi

We show the results of our analysis of the pulse broadening phenomenon in 25 pulsars at several frequencies using the data gathered with GMRT and Effelsberg radiotelescopes. Twenty two of these pulsars were not studied in that regard before…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Wojciech Lewandowski , Marta Dembska , Jaroslaw Kijak , Magdalena Kowalinska

Millisecond and binary pulsars are the most stable natural frequency standards which admits to introduce modified versions of universal and ephemeris time scales based correspondingly on the intrinsic rotation of pulsar and on its orbital…

Data Analysis, Statistics and Probability · Physics 2007-05-23 Sergei M. Kopeikin , Vladimir A. Potapov

The population of radio pulsars is observed to demonstrate certain polarization properties not explained by the conventional picture of pulsar polarization, namely frequency evolution of polarization, deviations of the linear polarization…

High Energy Astrophysical Phenomena · Physics 2023-08-02 Lucy Oswald , Aris Karastergiou , Simon Johnston

Cyclic spectral analysis is a signal processing technique designed to deal with stochastic signals whose statistics vary periodically with time. Pulsar radio emission is a textbook example of this signal class, known as cyclostationary…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Paul Demorest

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