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相关论文: Nanoarcsecond single-dish imaging of the Vela puls…

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We describe measurements of the size of the Vela pulsar via scintillation, using both fits to the distribution of intensity and measurements of the modulation index. We briefly discuss systematic effects other than source size that can…

I use a method based on interstellar scintillations for discerning information about source sizes on scales less than one micro-arc sec. I use a comprehensive model for a pulsar signal, scintillated amplitude modulated noise, that includes…

天体物理学 · 物理学 2007-05-23 J. M. Cordes

Using a novel technique, we achieve ~100 picoarcsecond resolution and set an upper bound of less than 4 km for the characteristic size of the Vela pulsar's emission region. Specifically, we analyze flux-density statistics of the Vela pulsar…

太阳与恒星天体物理 · 物理学 2012-09-20 Michael D. Johnson , Carl R. Gwinn , Paul Demorest

We derive the distribution of flux density of a compact source exhibiting strong diffractive scintillation. Our treatment accounts for arbitrary spectral averaging, spatially-extended source emission, and the possibility of intrinsic…

天体物理仪器与方法 · 物理学 2012-08-09 Michael D. Johnson , Carl R. Gwinn

We use interstellar scattering of the Vela pulsar to determine the size of its emission region. From interferometric phase variations on short baselines, we find that radio-wave scattering broadens the source by 3.4+/-0.3 milliarcseconds…

Aims. To investigate the flux density modulation from pulsars and the existence of specific behaviour of modulation index versus frequency. Methods. Several pulsars have been observed with the Effelsberg radio telescope at 8.35 GHz. Their…

太阳与恒星天体物理 · 物理学 2015-06-15 O. Maron , M. Serylak , J. Kijak , K. Krzeszowski , D. Mitra , A. Jessner

We present measurements of the size of the Vela pulsar in 3 gates across the pulse, from observations of the distribution of intensity. We calculate the effects on this distribution of noise in the observing system, and measure and remove…

We present the results of flux density monitoring of PSR B0329+54 at the frequency of 4.8 GHz using the 32-meter TCfA radiotelescope. The observations were conducted between 2002 and 2005. The main goal of the project was to find…

星系天体物理 · 物理学 2015-05-28 Wojciech Lewandowski , Jaroslaw Kijak , Yashwant Gupta , Krzysztof Krzeszowski

Polarisation measurements of pulsars offer an unique insight into the geometry of the emission regions in the neutron star magnetosphere. Therefore, they provide observational constraints on the different models proposed for the pulsar…

高能天体物理现象 · 物理学 2014-09-08 P. Moran , R. P. Mignani , A. Shearer

Refractive scintillation effects are powerful techniques for discriminating between different models proposed for the electron density fluctuation spectrum in the ISM. Data from our long-term scintillation study of 18 pulsars in the DM…

天体物理学 · 物理学 2009-10-31 N. D. Ramesh Bhat , Yashwant Gupta , A. Pramesh Rao

The high sensitivity and wide frequency coverage of the Murchison Widefield Array allow for the measurement of the spectral scaling of the pulsar scattering timescale, $\alpha$, from a single observation. Here we present three case studies…

高能天体物理现象 · 物理学 2019-04-17 F. Kirsten , N. D. R. Bhat , B. W. Meyers , J. -P. Macquart , S. E. Tremblay , S. M. Ord

Quasi-continuous observations of PSR B03239+54 over 20 days using the Nanshan 25-m telescope at 1540 MHz have been used to study the effects of refractive scintillation on the pulsar flux density and diffractive scintillation properties.…

天体物理学 · 物理学 2009-11-13 N. Wang , Z. Yan , R. N. Manchester , H. X. Wang

We demostrate that the measurement of fluctuations of polarization due to the galactic interstellar scintillations may be used to study the structure of the radiation field at compact radio sources. We develop a mathematical formalism and…

天体物理学 · 物理学 2009-10-31 Mikhail V. Medvedev

We present high time resolution observations of single pulses from the Vela pulsar (PSR B0833-45) made with a baseband recording system at observing frequencies of 660 and 1413 MHz. We have discovered two startling features in the 1413 MHz…

天体物理学 · 物理学 2009-11-06 Simon Johnston , Willem van Straten , Michael Kramer , Matthew Bailes

We present results of the analysis of interstellar scintillation in PSR B0823+26. Observations were conducted at a frequency of 1.7 GHz using the 32-m Torun Centre for Astronomy radio telescope. More than 50 observing sessions, lasting on…

高能天体物理现象 · 物理学 2013-10-31 M. Daszuta , W. Lewandowski , J. Kijak

We studied the turbulence spectrum of the local interstellar plasma in the direction of PSR J0437-4715, on the basis of our observations and those reported earlier by others. We combine these data to form a structure function for the…

天体物理学 · 物理学 2009-11-11 T. V. Smirnova , C. R. Gwinn , V. I. Shishov

We compare the noise in interferometric measurements of the Vela pulsar from ground- and space-based antennas with theoretical predictions. The noise depends on both the flux density and the interferometric phase of the source. Because the…

In this work we present a revised measurement of the phase-averaged optical polarisation of the Vela pulsar (PSR B0833-45), for which only one value has been published so far (Wagner & Seifert 2000). Our measurement has been obtained…

天体物理学 · 物理学 2009-11-13 R. P. Mignani , S. Bagnulo , J. Dyks , G. Lo Curto , A. Slowikowska

We apply a theory of wave propagation through a turbulent medium to the scattering of radio waves in pulsar magnetospheres. We find that under conditions of strong density modulation the effects of magnetospheric scintillations in…

天体物理学 · 物理学 2009-10-31 Maxim Lyutikov , Anuj Parikh
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