相关论文: Low-frequency pulse profile variation in PSR B2217…

LOFAR offers the unique capability of observing pulsars across the 10-240 MHz frequency range with a fractional bandwidth of roughly 50%. This spectral range is well-suited for studying the frequency evolution of pulse profile morphology…

Interstellar scattering is known to broaden distant objects spatially and temporally. The latter aspect is difficult to analyse, unless the signals carry their own time stamps. Pulsars are so kind to do us this favour. Typically the…

Interstellar scattering (ISS) of radio pulsar emission can be used as a probe of the ionised interstellar medium (IISM) and causes corruptions in pulsar timing experiments. Two types of ISS phenomena (intensity scintillation and pulse…

Radio emission propagating over an Earth-pulsar line of sight provides a unique probe of the intervening ionized interstellar medium (ISM). Variations in the integrated electron column density along this line of sight, or dispersion measure…

We present the highest-quality polarisation profiles to date of 16 non-recycled pulsars and four millisecond pulsars, observed below 200 MHz with the LOFAR high-band antennas. Based on the observed profiles, we perform an initial…

Refraction of pulsar radiation by electron density irregularities in the interstellar medium sometimes produces multiple imaging of pulsars which can lead to periodic oscillations of intensity in pulsar dynamic spectra records. Such events…

Radio pulsars emit regular bursts of radio radiation that propagate through the interstellar medium (ISM), the tenuous gas and plasma between the stars. Previously known dispersive properties of the ISM cause low frequency pulses to be…

Propagation effects in the interstellar medium and intrinsic profile changes can cause variability in the timing of pulsars, which limits the accuracy of fundamental science done via pulsar timing. One of the best timing pulsars, PSR…

Low-frequency spectral studies of radio pulsars represent a key method for uncovering their emission mechanisms, magnetospheric structure, and signal interactions with the surrounding interstellar medium (ISM). In recent years, more…

We report the detection of 48 millisecond pulsars (MSPs) out of 75 observed thus far using the LOFAR in the frequency range 110-188 MHz. We have also detected three MSPs out of nine observed in the frequency range 38-77 MHz. This is the…

We give a new numerical model of pulsar pulse radiation through the interstellar medium (ISM) considering the propagation effects. It explains the deficit of a scattering measure at the decameter range of frequencies that leads to the…

We report here on variable propagation effects in over twenty years of multi-frequency timing analysis of pulsar PSR B1937+21 that determine small-scale properties of the intervening plasma as it drifts through the sight line. The phase…

Scintillation of pulsar radio signals caused by the interstellar medium can in principle be used for interstellar interferometry. Changes of the dynamic spectra as a function of pulsar longitude were in the past interpreted as having…

We report on the detection of the millisecond pulsar PSR J0437-4715 with the Murchison Widefield Array (MWA) at a frequency of 192 MHz. Our observations show rapid modulations of pulse intensity in time and frequency that arise from…

Pulsar timing at low frequencies offers a powerful tool for studying the interstellar medium. Additionally, pulsar observations in the ecliptic enables us to study the effects of the solar wind which becomes much more prominent at low radio…

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…

In this paper we present recent Low Frequency Array (LOFAR) observations of the pulsar J1740+1000. We confirm that its spectrum has a turnover at 260 MHz, which is unusual for a typical pulsar. We argue that in this case interferometric…

Pulsar radio emission undergoes dispersion due to the presence of free electrons in the interstellar medium (ISM). The dispersive delay in the arrival time of pulsar signal changes over time due to the varying ISM electron column density…

The quasi-periodic feature of 1-10 years exhibited in pulsar timing noise has not been well understood since 1980. The recently demonstrated correlation between timing noise and variation of pulse profile motivates us to further investigate…

One of the major challenges for pulsar timing array (PTA) experiments is the mitigation of the effects of the turbulent interstellar medium (ISM) from timing data. These can potentially lead to measurable delays and/or distortions in the…