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Related papers: Parametrization of Crab pulsar spectrum

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We consider parameterized exponential integrals coming from the time evolution of the probability distribution of Brownian motion on globally subanalytic sets. We establish definability results and asymptotic expansions.

Classical Analysis and ODEs · Mathematics 2017-10-20 Tobias Kaiser , Julia Ruppert

The asymptotic iteration method is applied, to calculate the angular spheroidal eigenvalues $\lambda^{m}_{\ell}(c)$ with arbitrary complex size parameter $c$. It is shown that, the obtained numerical results of $\lambda^{m}_{\ell}(c)$ are…

Quantum Physics · Physics 2009-11-13 T. Barakat , K. Abodayeh , B. Abdallah , O. M. Al-Dossary

Besides the relation between the wave vector $\bm k$ and the complex frequency $\omega$, wave polarization is useful for characterizing the properties of a plasma wave. The polarization of the electromagnetic fields, $\delta \bm E$ and…

Plasma Physics · Physics 2021-03-31 Hua-sheng Xie , Richard Denton , Jin-song Zhao , Wen Liu

We present the results of a new, comprehensive investigation of the radio spectral index of the Crab Nebula supernova remnant. New data at 74 MHz are combined with data at 327 MHz, 1.5 GHz and 5 GHz. In contrast to previous claims, little…

Astrophysics · Physics 2009-10-30 M. F. Bietenholz , N. Kassim , D. A. Frail , R. A. Perley , W. C. Erickson , A. R. Hajian

The Crab Nebula is used by many instruments as a calibration source, in particular at high energy, where it is one of the brightest celestial object. The spectrometer INTEGRAL SPI (20 keV - 8 MeV), in operation since October 2002, offers a…

High Energy Astrophysical Phenomena · Physics 2020-09-02 E. Jourdain , J. P. Roques

Using the Westerbork Synthesis Radio Telescope (WSRT), we obtained high-time-resolution measurements of the full (linear and circular) polarization of the Crab pulsar. Taken at a resolution of 1/8192 of the 34-ms pulse period (i.e.,…

We analyzed four epochs of beamformed EVN data of the Crab Pulsar at 1658.49 MHz. With the high sensitivity resulting from resolving out the Crab Nebula, we are able to detect even the faint high-frequency components in the folded profile.…

High Energy Astrophysical Phenomena · Physics 2023-09-18 Rebecca Lin , Marten H. van Kerkwijk

The angular broadening of compact radio sources observed through a medium having turbulent density irregularities is usually estimated using the phase structure function. We employ an exact formulation for the phase structure function that…

Solar and Stellar Astrophysics · Physics 2014-06-23 Madhusudan Ingale , Prasad Subramanian , Iver H. Cairns

Of the current known pulsars, the Crab pulsar (B0531+21) is one of the most promising sources of gravitational waves. The relatively large timing noise of the Crab causes its phase evolution to depart from a simple spin-down model. This…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Matthew Pitkin , Graham Woan

We discuss the recent detection of pulsed gamma-ray emission from the Crab Pulsar above 100 GeV with the VERITAS array of atmospheric Cherenkov telescopes. Gamma-ray emission at theses energies is not expected in present pulsar models. We…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Andrew McCann

A pulsar timing system has been operating in the 18-cm band at the Urumqi Astronomical Observatory 25-m telescope since mid-1999. Frequency resolution allowing dedispersion of the pulsar signals is provided by a 2X128X2.5 MHz…

Astrophysics · Physics 2009-11-07 N. Wang , R. N. Manchester , J. Zhang , X. J. Wu , A. Yusup , A. G. Lyne , K. S. Cheng , M. Z. Chen

A finite sum of exponential functions may be expressed by a linear combination of powers of the independent variable and by successive integrals of the sum. This is proved for the general case and the connection between the parameters in…

Data Analysis, Statistics and Probability · Physics 2007-05-23 Bernhard Kaufmann

Previously unseen profile components of the Crab pulsar have been discovered in a study of the frequency-dependent behavior of its average pulse profile between 0.33 and 8.4 GHz. One new component, 36 degrees ahead of the main pulse at 1.4…

Astrophysics · Physics 2009-10-28 D. A. Moffett , T. H. Hankins

Polarisation measurements of pulsars and of their pulsar wind nebulae (PWNe) are uniquely able to provide deep insights into the highly magnetised relativistic environment of young, rotation-powered isolated neutron stars (INSs). Besides…

Astrophysics of Galaxies · Physics 2009-04-14 R. P. Mignani

The linear polarisation fraction and angle of the hard X-ray emission from the Crab provide unique insight into high energy radiation mechanisms, complementing the usual imaging, timing and spectroscopic approaches. Results have recently…

High Energy Astrophysical Phenomena · Physics 2018-03-14 M. Chauvin , H. -G. Florén , M. Friis , M. Jackson , T. Kamae , J. Kataoka , T. Kawano , M. Kiss , V. Mikhalev , T. Mizuno , H. Tajima , H. Takahashi , N. Uchida , M. Pearce

Owing to the dramatic evolution of telescopes as well as optical detectors in the last 20 yrs, we are now able to measure anew the proper motion of the Crab pulsar, after the classical result of Wyckoff and Murray (1977) in a time span 40…

Astrophysics · Physics 2007-05-23 PATRIZIA A. CARAVEO , ROBERTO MIGNANI

The Crab Pulsar has exhibited numerous glitches accompanied by persistent shifts in its spin-down rate. The explanation of the observed persistent shifts remain a challenge. We perform a detailed Bayesian analysis to compare four…

High Energy Astrophysical Phenomena · Physics 2024-09-30 Chun Huang , Xiao-Ping Zheng

One-bit quantization has garnered significant attention in recent years for various signal processing and communication applications. Estimating model parameters from one bit quantized data can be challenging, particularly when the…

Signal Processing · Electrical Eng. & Systems 2025-04-01 Nadav E. Rosenthal , Joseph Tabrikian

The quest for primordial gravitational waves enclosed in the Cosmic Microwave Background (CMB) polarization B-modes signal motivates the development of a new generation of high sensitive experiments (e.g. CMB-S4, LiteBIRD) that would allow…

We examined the spatially resolved polarization variations in the Crab Nebula over 2 yr, using observational data from the Imaging X-ray Polarimetry Explorer, and offer key insights into its magnetic field structures and evolution. The…

High Energy Astrophysical Phenomena · Physics 2025-04-15 Chao Zuo , Fei Xie , Mingyu Ge , Wei Deng , Kuan Liu , Fabio La Monaca , Alessandro Di Marco , Wenhao Wei , Wei Chen