Daily observations of interstellar scintillation in PSR B0329+54

Wang, N.; Yan, Zhen; Manchester, R. N.; Wang, H. X.

doi:10.1111/j.1365-2966.2008.12864.x

Cited by 23 publications

(20 citation statements)

References 33 publications

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“…5, Wang et al 2008) leads to the conclusion that even a slight change of m RISS , and in turn the saturation level D sat , could lead to timescale even a half an order of magnitude higher than the 8 h they quote, and we think that is exactly what happened. In Wang et al (2008) defense we may note that we had one session in our data that is coincident with their March 2004 observations, as we performed a 38-h observation between March 15 and 17 of 2004, and our structure function did not saturate as well, which may suggest that the fluctuations of the flux density were untypical during that period.…”

Section: Scintillation Parametersmentioning

confidence: 94%

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Diffractive and refractive timescales at 4.8 GHz in PSR B0329+54

Lewandowski

Kijak

Gupta

et al. 2011

A&A

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Aims. We present the results of flux density monitoring of PSR B0329+54 at the frequency of 4.8 GHz using the 32-m TCfA radiotelescope. The observations were conducted between 2002 and 2005. The main goal of the project was to find interstellar scintillation (ISS) parameters for the pulsar at the frequency at which it was never studied in detail. To achieve this, the 20 observing sessions consisted of 3-min integrations, which on average lasted 24 h. This gave us sufficient sensitivity to all types of flux density variations over a wide range of timescales. The character of the observations makes our project unique amongst other ISS oriented observing programs, at least at high frequency. Methods. Flux density time series obtained for each session were analysed using structure functions. For some of the individual sessions as well as for the general average structure function we were able to identify two distinctive timescales present, the timescales of diffractive and refractive scintillations. To the best of our knowledge, this is the first case when both scintillation timescales, t DISS = 42.7 min and t RISS = 305 min, were observed simultaneously in a uniform data set and estimated using the same method. Results. The obtained values of the ISS parameters combined with the data found in the literature allowed us to study the frequency dependence of these parameters over a wide range of observing frequencies, which is crucial for understanding the ISM turbulence. We found that the Kolmogorov spectrum is not best suited for describing the density fluctuations of the ISM, and a power-law spectrum with β = 4 seems to fit better with our results. We were also able to estimate the transition frequency (transition from strong to weak scintillation regimes) as ν c = 10.1 GHz, much higher than was previously predicted. We were also able to estimate the strength of scattering parameter u = 2.67 and the Fresnel scale as r F = 6.7 × 10 8 m.

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Section: Scintillation Parametersmentioning

confidence: 94%

“…by Wang et al (2008), which are represented by triangles in their respective plots. These points stray by much from the rest of the data, and contradict the earlier estimates at the same frequency (1540 MHz) given by Wang et al (2005).…”

Section: Scintillation Parametersmentioning

confidence: 99%

Diffractive and refractive timescales at 4.8 GHz in PSR B0329+54

Lewandowski

Kijak

Gupta

et al. 2011

A&A

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“…Its scintillation has been observed by many authors (see Table 2) in a range of frequencies from 327 MHz to more than 10 GHz. Although the decorrelation bandwidths and scintillation time scales have somehow different values from many observations even at one given band (e.g., Stinebring et al 1996;Wang et al 2008), the scintillation parameters clearly follow a power law with observational frequencies (Cordes et al 1985;Lewandowski et al 2011), which we discuss in Sect. 4.1.…”

Section: Psr B0329+54mentioning

confidence: 89%

Jiamusi pulsar observations

Wang

Han²,

Zhang

et al. 2018

A&A

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Context. Pulsars scintillate. Dynamic spectra show brightness variation of pulsars in the time and frequency domain. Secondary spectra demonstrate the distribution of fluctuation power in the dynamic spectra. Aims. Dynamic spectra strongly depend on observational frequencies, but were often observed at frequencies lower than 1.5 GHz. Scintillation observations at higher frequencies help to constrain the turbulence feature of the interstellar medium over a wide frequency range and can detect the scintillations of more distant pulsars. Methods. Ten pulsars were observed at 2250 MHz (S-band) with the Jiamusi 66 m telescope to study their scintillations. Their dynamic spectra were first obtained, from which the decorrelation bandwidths and timescales of diffractive scintillation were then derived by autocorrelation. Secondary spectra were calculated by forming the Fourier power spectra of the dynamic spectra. Results. Most of the newly obtained dynamic spectra are at the highest frequency or have the longest time span of any published data for these pulsars. For PSRs B0540 + 23, B2324 + 60, and B2351 + 61, these were the first dynamic spectra ever reported. The frequency dependence of the scintillation parameters indicates that the intervening medium can rarely be ideally turbulent with a Kolmogorov spectrum. The thin-screen model worked well at S-band for the scintillation of PSR B1933 + 16. Parabolic arcs were detected in the secondary spectra of three pulsars, PSRs B0355 + 54, B0540 + 23, and B2154 + 40, all of which were asymmetrically distributed. The inverted arclets of PSR B0355 + 54 were seen to evolve along the main parabola within a continuous observing session of 12 h, from which the angular velocity of the pulsar was estimated. This was consistent with the measurement by very long baseline interferometry.

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“…Several authors have measured the pulse broadening caused by multipath propagation through the interstellar medium to investigate the LOS ISM effects and to model the ionized content of the ISM (Bhat et al 2004;Taylor and Cordes 1993;Bhat and Gupta 2002;Lazio 2002, 2003). Other authors have considered the flux density variations (Rickett and Lyne 1990;LaBrecque et al 1994;Esamdin et al 2000Esamdin et al , 2004Wang et al 2005) and the measurement of DISS parameters to derive the scattering strength and scintillation speeds (Gupta et al 1994;Stinebring et al 1996;Bhat et al 1999a;Wang et al 2001Wang et al , 2008. Recently, Stinebring et al (2000) monitored the radio flux density of 21 pulsars at 610 MHZ for five years and presented the structure functions of flux density time series.…”

Section: Introductionmentioning

confidence: 97%

Two-component scattering model and the electron density spectrum

Zhou

Tan

Esamdin

et al. 2009

Astrophys Space Sci

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In this paper, we discuss a rigorous treatment of the refractive scintillation caused by a two-component interstellar scattering medium and a Kolmogorov form of density spectrum. It is assumed that the interstellar scattering medium is composed of a thin-screen interstellar medium (ISM) and an extended interstellar medium. We consider the case that the scattering of the thin screen concentrates in a thin layer represented by a δ function distribution and that the scattering density of the extended irregular medium satisfies the Gaussian distribution. We investigate and develop equations for the flux density structure function corresponding to this two-component ISM geometry in the scattering density distribution and compare our result with the observations. We conclude that the refractive scintillation caused by this two-component ISM scattering gives a more satisfactory explanation for the observed flux density variation than does the single extended medium model. The level of refractive scintillation is strongly sensitive to the distribution of scattering material along the line of sight (LOS). The theoretical modulation indices are comparatively less sensitive to the scattering strength of the thin-screen medium, but they critically depend on the distance from the observer to the thin screen. The logarithmic slope of the structure function is sensitive to the scattering strength of the thin-screen medium, but is relatively insensitive to the thin-screen location. Therefore, the proposed model can be applied to interpret the structure functions of flux density observed in pulsar PSR B2111 + 46 and PSR B0136 + 57. The result suggests that the medium consists of a discontinuous distribution of plasma turbulence embedded in the interstellar medium. Thus our work provides some insight into the distribution of the scattering along the LOS to the pulsar PSR B2111 + 46 and PSR B0136 + 57.

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Daily observations of interstellar scintillation in PSR B0329+54

Cited by 23 publications

References 33 publications

Diffractive and refractive timescales at 4.8 GHz in PSR B0329+54

Diffractive and refractive timescales at 4.8 GHz in PSR B0329+54

Jiamusi pulsar observations

Two-component scattering model and the electron density spectrum

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