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相关论文: On gigahertz spectral turnovers in pulsars

200 篇论文

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…

高能天体物理现象 · 物理学 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…

高能天体物理现象 · 物理学 2018-02-07 Rahul Basu , Karolina Rożko , Jarosław Kijak , Wojciech Lewandowski

The radio continuum spectra of pulsars (PSRs) exhibit a wide variety of shapes, that are interpreted as pure and broken power laws, power laws with turnovers or cut-offs, and logarithmic-parabolic profiles. A notable fraction of these have…

星系天体物理 · 物理学 2025-11-24 Mario G. Abadi , Gabriela Castelletti , Namir E. Kassim

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…

星系天体物理 · 物理学 2011-06-30 J. Kijak , W. Lewandowski , O. Maron , Y. Gupta , A. Jessner

Pulsar timing arrays provide a unique means to detect nanohertz gravitational waves through long-term measurements of pulse arrival times from an ensemble of millisecond pulsars. After years of observations, some timing array pulsars have…

高能天体物理现象 · 物理学 2020-07-30 Boris Goncharov , Xing-Jiang Zhu , Eric Thrane

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…

天体物理学 · 物理学 2009-11-11 J. Kijak , Y. Gupta , K. Krzeszowski

We present a model that explains the observed deviation of the spectra of some pulsars and magnetars from the power-law spectra which are seen in the bulk of the pulsar population. Our model is based on the assumption that the observed…

高能天体物理现象 · 物理学 2015-08-06 Wojciech Lewandowski , Karolina Rożko , Jarosław Kijak , George I. Melikidze

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…

高能天体物理现象 · 物理学 2025-04-14 K. Rożko , J. Kijak , R. Basu , P. Dabhade , W. Lewandowski

The North Polar Spur (NPS) is a giant structure that is clearly visible in both radio and X-ray all-sky maps. We analyzed broadband radio observations covering a range between 22 MHz and 70 GHz to systematically analyze the…

星系天体物理 · 物理学 2023-10-17 Iwashita Ryoji , Kataoka Jun , Sofue Yoshiaki

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…

太阳与恒星天体物理 · 物理学 2015-06-15 Samuel D. Bates , Duncan R. Lorimer , Joris P. W. Verbiest

We report the detailed spectral measurements over a wide frequency range of three pulsars: J1741-3016, J1757-2223 and J1845-0743, using the Giant Metrewave Radio Telescope, which allowed us to identify them as a new gigahertz-peaked spectra…

高能天体物理现象 · 物理学 2022-01-11 K. Rożko , R. Basu , J. Kijak , W. Lewandowski

We present the first direct evidence for turn-over in pulsar radio spectra at high frequencies. Two pulsars are now shown to have a turn-over frequency > 1GHz. We also find some evidence that the peak frequency of turn-over in pulsar…

天体物理学 · 物理学 2007-05-23 J. Kijak , Y. Gupta , K. Krzeszowski

Recently published results \citep{kijak2011b} indicated the evidence for a new aspect in radio pulsars spectra. We studied the radio spectrum of PSR B1259-63 in an unique binary with Be star LS 2883 and showed that this pulsar undergoes a…

星系天体物理 · 物理学 2012-12-06 M. Dembska , J. Kijak , W. Lewandowski

We studied the radio spectrum of PSR B1259-63 in an unique binary with Be star LS 2883 and showed that the shape of the spectrum depends on the orbital phase. We proposed a qualitative model which explains this evolution. We considered two…

太阳与恒星天体物理 · 物理学 2015-06-12 Marta Dembska , Jarosław Kijak , Wojciech Lewandowski

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…

高能天体物理现象 · 物理学 2016-02-22 Rahul Basu , Karolina Rożko , Wojciech Lewandowski , Jarosław Kijak , Marta Dembska

The X-ray and gamma-ray spectrum of rotation-powered millisecond pulsars is investigated in a model for acceleration and pair cascades on open field lines above the polar caps. Although these pulsars have low surface magnetic fields, their…

天体物理学 · 物理学 2016-08-30 Alice K. Harding , Vladimir V. Usov , Alex G. Muslimov

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…

天体物理学 · 物理学 2007-05-23 A. von Hoensbroech , J. Kijak , A. Krawczyk

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…

天体物理学 · 物理学 2010-05-19 F. V. Prigara

We have explored, in the general framework of the ``young source'' scenario, evolutionary models for GHz Peaked Spectrum (GPS) galaxies and quasars which reproduce the observed counts, redshift and peak frequency distributions of currently…

天体物理学 · 物理学 2007-05-23 G. De Zotti , G. L. Granato , L. Silva , D. Maino , L. Danese

This study presents a comprehensive analysis of the spectral properties of 886 pulsars across a wide frequency range from 20MHz to 343.5GHz, including a total of 86 millisecond pulsars. The majority of the pulsars exhibit power-law behavior…

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