Five Years of Pulsar Flux Density Monitoring: Refractive Scintillation and the Interstellar Medium

Stinebring, Daniel R.; Smirnova, T. V.; Hankins, T. H.; Hovis, Jennifer S.; Kaspi, V. M.; Kempner, Joshua C.; Myers, E.; Nice, D. J.

doi:10.1086/309201

Cited by 99 publications

(123 citation statements)

References 30 publications

Supporting

Mentioning

111

Contrasting

Order By: Relevance

“…For this pulsar, Stinebring et al (1996) studied the refractive scintillation properties in detail, observing flux density variations at 610 MHz of about 30%. This is consistent with the results obtained by Stinebring et al (2000) and those by Bhat et al (1999a) at 327 MHz who also obtained measurements for PSR B1133+16. For the latter pulsar, we estimate ∆t RISS ∼ 80 min at 1412 MHz which is the same as our observing time for this pulsar.…”

Section: Estimated and Observed Parameterssupporting

confidence: 93%

See 1 more Smart Citation

Simultaneous single-pulse observations of radio pulsars

Krämer

Karastergiou

Gupta

et al. 2003

A&A

View full text Add to dashboard Cite

Abstract.In this paper we demonstrate that a large, unexplored reservoir of information about pulsar emission exists, that is directly linked to the radiating particles and their radiation process: We present a study of flux density measurements of individual pulses simultaneously observed at four different frequencies. Correcting for effects caused by the interstellar medium, we derive intrinsic flux density spectra of individual radio pulses observed at several frequencies for the first time. Pulsar B0329+54 was observed at 238, 626, 1412 and 4850 MHz, while observations of PSR B1133+16 were made at 341, 626, 1412 and 4850 MHz. We derive intrinsic pulse-to-pulse modulation indices which show a minimum around 1 GHz. Correlations between the flux densities of different frequency pairs worsen as the frequency separation widens and also tend to be worse for outer profile components. The single pulse spectra of PSR B0329+54 resemble the spectra of the integrated profile. However, the spectral index distributions for the single pulses of PSR B1133+16 show significant deviations from a Gaussian. This asymmetry is caused by very strong pulses with flux densities exceeding the mean value by more than a factor of ten. These strong pulses occur preferentially at the trailing edge of the leading component and appear to be broadband in most cases. Their properties are similar to those of so-called giant pulses, suggesting that these phenomena are related.

show abstract

Section: Estimated and Observed Parameterssupporting

confidence: 93%

“…For the latter pulsar, we estimate ∆t RISS ∼ 80 min at 1412 MHz which is the same as our observing time for this pulsar. Based on the results by Stinebring et al (1996Stinebring et al ( , 2000, Bhat et al (1999b) …”

Section: Estimated and Observed Parametersmentioning

confidence: 99%

Simultaneous single-pulse observations of radio pulsars

Krämer

Karastergiou

Gupta

et al. 2003

A&A

View full text Add to dashboard Cite

show abstract

“…For others, variations could be due to a cloud or gradient along the LOS. Scintillation parameters and fluxes could indicate whether variations were due to clumps, refraction, scattering variability, or local increases in electron density (such as solar wind; Stinebring & Condon 1990;Clegg et al 1998;Stinebring et al 2000;Lentati et al 2017). Future work may result in some determination, particularly if scintillation parameters over time are available and incorporated.…”

Section: Discussionmentioning

confidence: 99%

The NANOGrav Nine-year Data Set: Measurement and Analysis of Variations in Dispersion Measures

Jones

McLaughlin

Lam

et al. 2017

ApJ

View full text Add to dashboard Cite

We analyze dispersion measure (DM) variations of 37 millisecond pulsars in the nine-year North American Nanohertz Observatory for Gravitational Waves (NANOGrav) data release and constrain the sources of these variations. DM variations can result from a changing distance between Earth and the pulsar, inhomogeneities in the interstellar medium, and solar effects. Variations are significant for nearly all pulsars, with characteristic timescales comparable to or even shorter than the average spacing between observations. Five pulsars have periodic annual variations, 14 pulsars have monotonically increasing or decreasing trends, and 14 pulsars show both effects. Of the four pulsars with linear trends that have line-of-sight velocity measurements, three are consistent with a changing distance and require an overdensity of free electrons local to the pulsar. Several pulsars show correlations between DM excesses and lines of sight that pass close to the Sun. Mapping of the DM variations as a function of the pulsar trajectory can identify localized interstellar medium features and, in one case, an upper limit to the size of the dispersing region of 4 au. Four pulsars show roughly Kolmogorov structure functions (SFs), and another four show SFs less steep than Kolmogorov. One pulsar has too large an uncertainty to allow comparisons. We discuss explanations for apparent departures from a Kolmogorov-like spectrum, and we show that the presence of other trends and localized features or gradients in the interstellar medium is the most likely cause.

show abstract

“…A generally accepted point of view at the present time is that scattering as well as diffractive and refractive interstellar scintillation effects are caused by electron density fluctuations in the interstellar medium (ISM) (Scheuer 1968;Rickett 1969;Sieber 1982;Rickett et al 1984;Armstrong et al 1995;Stinebring et al 2000). It could be shown that for the different kinds of pulsar observations connected with the propagation through the interstellar plasma, a composite structure function of phase fluctuations can be constructed and that this structure function follows a power law over a very wide range of scales (10 6 to 10 13 m).…”

Section: Introductionmentioning

confidence: 99%

Measurements of the interstellar turbulent plasma spectrum of PSR B0329+54 using multi-frequency observations of interstellar scintillation

Shishov

Smirnova

Sieber

et al. 2003

A&A

View full text Add to dashboard Cite

Abstract. Interstellar scintillation multi-frequency observations of PSR 0329+54 in the frequency range from 102 MHz to 5 GHz were analysed to estimate the spectrum of interstellar plasma inhomogeneities in the direction of this pulsar. Based on the theory of diffractive scintillation, the composite structure function of phase fluctuations covering a large range of turbulence scales was constructed. We found that the spectrum is well described by a power law with n = 3.5 for scales from 10 6 to 10 9 m, which differs from the value known for a Kolmogorov spectrum. We can, however, within the accuracy of our data not exclude a Kolmogorov spectrum. It became also clear that angular refraction of emission must be taken into account to fit the data points at all observing frequencies. The size of the irregularities responsible for the angular refraction is estimated to be about 3 × 10 13 m. They can be identified with clouds of neutral hydrogen that can be considered as holes of electron density.

show abstract

Five Years of Pulsar Flux Density Monitoring: Refractive Scintillation and the Interstellar Medium

Cited by 99 publications

References 30 publications

Simultaneous single-pulse observations of radio pulsars

Simultaneous single-pulse observations of radio pulsars

The NANOGrav Nine-year Data Set: Measurement and Analysis of Variations in Dispersion Measures

Measurements of the interstellar turbulent plasma spectrum of PSR B0329+54 using multi-frequency observations of interstellar scintillation

Contact Info

Product

Resources

About