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Related papers: Turn-over in pulsar spectra above 1 GHz

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The main aim is to investigate the possibility of a high frequency turn-over in the radio spectrum of pulsars. Using the GMRT, multi-frequency flux density measurements of several candidate pulsars have been carried out and their spectra…

Astrophysics · Physics 2009-11-11 J. Kijak , Y. Gupta , K. Krzeszowski

We investigate a high frequency turn-over effect in radio spectra for pulsars with positive or flat spectral index. Using GMRT and Effelsberg observatory, we estimated the flux density to reconstruct pulsar spectra. We find objects that…

Astrophysics of Galaxies · Physics 2011-06-30 J. Kijak , W. Lewandowski , O. Maron , Y. Gupta , A. Jessner

Pulsars are known to emit non-thermal radio emission that is generally a power-law function of frequency. In some cases, a turnover is seen at frequencies around 100~MHz. Kijak et al. have reported the presence of a new class of ''Gigahertz…

High Energy Astrophysical Phenomena · Physics 2015-11-11 Kaustubh Rajwade , Duncan R Lorimer , Loren D Anderson

We have collected pulsar flux density observations and compiled spectra of 281 objects. The database of Lorimer et al. (\cite{lorimer}) has been extended to frequencies higher than 1.4 GHz and lower than 300 MHz. Our results show that above…

Astrophysics · Physics 2009-10-31 Olaf Maron , Jaroslaw Kijak , Michael Kramer , Richard Wielebinski

The behaviour of the pulsar spectrum at high radio frequencies can provide decisive information about the nature of the radio emission mechanism. We report recent observations of a selected sample of pulsars at lambda=9mm (32 GHz) with the…

Astrophysics · Physics 2009-11-13 O. Loehmer , A. Jessner , M. Kramer , R. Wielebinksi , O. Maron

The analytical expression for frequency of the maximum of radio emission intensity in pulsars with free electron emission from the stellar surface has been found. We have explained the correlation, known from observations, between the…

Solar and Stellar Astrophysics · Physics 2015-06-11 V. M. Kontorovich , A. B. Flanchik

We report the flux measurement of the Vela like pulsar B1800-21 at the low radio frequency regime over multiple epochs spanning several years. The spectrum shows a turnover around the GHz frequency range and represents a typical example of…

High Energy Astrophysical Phenomena · Physics 2016-02-22 Rahul Basu , Karolina Rożko , Wojciech Lewandowski , Jarosław Kijak , Marta Dembska

We have analyzed the polarization properties of pulsars at an observing frequency of 4.9 GHz. Together with low frequency data, we are able to trace polarization profiles over more than three octaves into an interesting frequency regime. At…

Astrophysics · Physics 2007-05-23 A. von Hoensbroech , J. Kijak , A. Krawczyk

In their catalogue of pulsars' radio spectra, Swainston et al. (2022, PASA, 39, e056) distinguish between five different forms of these spectra: those that can be fitted with (i) a simple power law, (ii) a broken power law, (iii) a…

High Energy Astrophysical Phenomena · Physics 2024-03-29 Houshang Ardavan

In this paper we present the first observations of a large sample of millisecond pulsars at frequencies of 2.7 GHz and 4.9 GHz. Our new flux measurements extend the known spectra for millisecond pulsars to the highest frequencies to date.…

Astrophysics · Physics 2009-10-31 M. Kramer , C. Lange , D. R. Lorimer , D. C. Backer , K. M. Xilouris , A. Jessner , R. Wielebinski

Detecting and studying pulsars above a few GHz in the radio band is challenging due to the typical faintness of pulsar radio emission, their steep spectra, and the lack of observatories with sufficient sensitivity operating at high…

High Energy Astrophysical Phenomena · Physics 2018-06-29 Pablo Torne

Motivated by recent results on the location of the radio emission in pulsar magnetospheres, we have developed a model which can account for the large diversity found in the average profile shapes of pulsars. At the centre of our model lies…

Astrophysics · Physics 2009-11-13 A. Karastergiou , S. Johnston

We report the measurements of low radio frequency spectra of fourteen gigahertz-peaked spectra (GPS) pulsar candidates, between 300~MHz and 700~MHz, using the upgraded Giant Meterwave Radio Telescope. Combining newly collected measurements…

High Energy Astrophysical Phenomena · Physics 2025-04-14 K. Rożko , J. Kijak , R. Basu , P. Dabhade , W. Lewandowski

The flux density spectra of radio pulsars are known to be steep and, to first order, described by a power-law relationship of the form S_{\nu} \propto \nu^{\alpha}, where S_{\nu} is the flux density at some frequency \nu and \alpha is the…

Solar and Stellar Astrophysics · Physics 2015-06-15 Samuel D. Bates , Duncan R. Lorimer , Joris P. W. Verbiest

At present three pulsars are known which clearly show a strongly increasing degree of circular polarization with frequency. As this is accompanied by a smooth decrease of linear polarization, we investigate, if this observation can be…

Astrophysics · Physics 2007-05-23 Alexis von Hoensbroech , Harald Lesch

We present the results of our radio interferometric observations of pulsars at 325 MHz and 610 MHz using the Giant Metrewave Radio Telescope (GMRT). We used the imaging method to estimate the flux densities of several pulsars at these radio…

High Energy Astrophysical Phenomena · Physics 2017-05-24 J. Kijak , R. Basu , W. Lewandowski , K. Rozko , M. Dembska

We have carried out a detailed study of the spectral nature of six pulsars surrounded by Pulsar wind nebulae (PWN). The pulsar flux density were estimated using the interferometric imaging technique of the Giant Metrewave Radio Telescope at…

High Energy Astrophysical Phenomena · Physics 2018-02-07 Rahul Basu , Karolina Rożko , Jarosław Kijak , Wojciech Lewandowski

Pulsars are famed for their rotational clock-like stability and their highly-repeatable pulse shapes. However, it has long been known that there are unexplained deviations (often termed "timing noise") from the rate at which we predict…

Astrophysics of Galaxies · Physics 2010-06-29 Andrew Lyne , George Hobbs , Michael Kramer , Ingrid Stairs , Ben Stappers

We have observed a total of 67 pulsars at five frequencies ranging from 243 to 3100 MHz. Observations at the lower frequencies were made at the Giant Metre Wave Telescope in India and those at higher frequencies at the Parkes Telescope in…

Astrophysics · Physics 2009-11-13 Simon Johnston , Aris Karastergiou , Dipanjan Mitra , Yashwant Gupta

On the basis of the unified model of compact radio sources, the dependence of a turnover frequency in the smoothed radio spectrum of a pulsar upon the ratio of the dispersion measure to the period of a pulsar is obtained. This relation is…

Astrophysics · Physics 2010-05-19 F. V. Prigara
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