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相关论文: Parametrization of Crab pulsar spectrum

200 篇论文

We present a modified outer gap model to study the phase-resolved spectra of the Crab pulsar. A theoretical double peak profile of the light curve containing the whole phase is shown to be consistent with the observed light curve of the…

天体物理学 · 物理学 2009-06-23 J. J. Jia , Anisia P. S. Tang , J. Takata , H. K. Chang , K. S. Cheng

Using the high speed 2-d TRIFFID photometer, we have obtained phase resolved photometry of the Crab pulsar in UBV that allows us to flux the unpulsed light curve component. Following de-extinction, weighted least-square fitting indicates a…

天体物理学 · 物理学 2007-05-23 Aaron Golden , Andy Shearer , Gregory Beskin

We present updated hard X-ray polarization measurements of the Crab pulsar and nebula obtained with the balloon-borne polarimeter XL-Calibur in the ~19-64 keV energy range. During the flight, intermittent GPS-failure resulted in poorly…

We present results from a NuSTAR observation of the Crab made at a large off-axis angle of 1.5\degree. At these angles X-rays do not pass through the optics, but rather illuminate the detectors directly due to incomplete baffling. Due to…

高能天体物理现象 · 物理学 2017-05-31 Kristin K. Madsen , Karl Forster and , Brian W. Grefenstette , Fiona A. Harrison , Daniel Stern

We investigate polarization of high-energy emissions from the Crab pulsar in the frame work of the outer gap accelerator, following previous works of Cheng and coworkers. The recent version of the outer gap, which extends from inside the…

天体物理学 · 物理学 2016-08-31 J. Takata , H. -K. Chang , K. S. Cheng

We analyze the effect of polarized diffuse emission in the calibration of wide-beam mm-wave polarimeters, when using the Crab Nebula as a reference source for both polarized brightness and polarization angle. We show that, for CMB…

We use four observations with the European VLBI network to measure the first precise radio parallax of the Crab Pulsar. We found two in-beam extragalactic sources just outside the Crab Nebula, with one bright enough to use as a background…

高能天体物理现象 · 物理学 2023-08-02 Rebecca Lin , Marten H. van Kerkwijk , Franz Kirsten , Ue-Li Pen , Adam T. Deller

We have analyzed 16 years of observations dedicated to the Crab (pulsar + nebula) with the INTEGRAL SPI instrument to investigate its polarization properties. We find that the source presents a substantially polarized emission (PF = 24%) in…

高能天体物理现象 · 物理学 2019-09-25 E. Jourdain , J. P. Roques

We interpret $\gamma$-ray flares from the Crab Nebula as the signature of turbulence in the pulsar's electromagnetic outflow. Turbulence is triggered upstream by dynamical instability of the wind's oscillating magnetic field, and…

高能天体物理现象 · 物理学 2016-06-01 Jonathan Zrake

We have measured the linear polarisation of hard X-ray emission from the Crab in a previously unexplored energy interval, 20-120 keV. The introduction of two new observational parameters, the polarisation fraction and angle stands to…

Our high time resolution observations of individual pulses from the Crab pulsar show that the main pulse and interpulse differ in temporal behavior, spectral behavior, polarization and dispersion. The main pulse properties are consistent…

天体物理学 · 物理学 2009-06-23 J. A. Eilek , T. H. Hankins

We present a multicomponent model to explain the features of the pulsed emission and spectrum of the Crab Pulsar, on the basis of X and gamma-ray observations obtained with BeppoSAX, INTEGRAL and CGRO. This model explains the evolution of…

天体物理学 · 物理学 2007-05-23 E. Massaro , R. Campana , G. Cusumano , T. Mineo

Eclipsing binaries provide one of the most direct mechanisms for measuring stellar properties such as mass and radius, but historically, determining these properties has been non-trivial and computationally prohibitive. As such, only a…

The sum of independent, but not necessary identically distributed, exponential random variables follows hypoexponential distribution. We focus on a particular case when all, but one rate parameters of the exponential variables are…

概率论 · 数学 2023-04-04 George Yanev

Time-resolved polarisation measurements of pulsars offer an unique insight into the geometry of their emission regions. Such measure\ ments provide observational constraints on the different models proposed for the pulsar emission…

We apply a synchro-curvature spectral emission model based on characterizing the dynamics of magnetospheric particles to fit the phase-average spectra of the most extended database for the non-thermal spectra of pulsars. We consider 36…

高能天体物理现象 · 物理学 2019-09-25 Diego F. Torres , Daniele Vigano , Francesco Coti Zelati , Jian Li

The Crab Nebula is an astrophysical system that exhibits complex morphological patterns at different observing frequencies. We carry out a systematic investigation of the structural complexity of the nebula using publicly available imaging…

适应与自组织系统 · 物理学 2024-02-20 Athokpam Langlen Chanu , Pravabati Chingangbam , Fazlu Rahman , R. K. Brojen Singh , Preeti Kharb

Context: The Crab pulsar is a bright $\gamma$-ray source detected at photon energies up to $\sim$1 TeV. Its phase-averaged and phase-resolved $\gamma$-ray spectra below 10 GeV exhibit exponential cutoffs while those above 10 GeV apparently…

高能天体物理现象 · 物理学 2021-05-05 Paul K. H. Yeung

We present a phase-dependent analysis of the polarized emission from the Crab pulsar based on three sets of observations by the Imaging X-ray Polarimetry Explorer (IXPE). We found that a phenomenological model involving a simple linear…

One of the most intriguing results from the gamma-ray instruments in orbit has been the detection of powerful flares from the Crab Nebula. These flares challenge our understanding of pulsar wind nebulae and models for particle acceleration.…