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Your search keyword '"Zhou, D J"' showing total 7 results
Start Over Author "Zhou, D J" Journal monthly notices of the royal astronomical society
7 results on '"Zhou, D J"'

2. Polarized radio emission of RRAT J1854+0306.

Author

Guo, Qi, Kong, Minzhi, Wang, P F, Yan, Y, and Zhou, D J

Subjects
PULSARS, ROTATIONAL motion, TELESCOPES, MORPHOLOGY, ANGLES
Abstract

Polarized radio emission of RRAT J1854+0306 is investigated with single pulses using Five-hundred-meter Aperture Spherical Telescope. Its emission is characterized by nulls, narrow and weak pulses, and occasional wide and intense bursts with a nulling fraction of 53.2 per cent. Its burst emission is typically of one rotation, and occasionally of two or three or even five rotations at the most, but without significant periodicity. The integrated pulse profile has an 'S'-shaped position angle curve that is superposed with orthogonal modes, from which geometry parameters are obtained. Individual pulses exhibit diverse profile morphology with single, double, or multiple peaks. The intensity and width of these pulses are highly correlated, and bright pulses generally have wide profiles with multiple peaks. These nulling behaviours, profile morphology, and polarization demonstrate that a rotating radio transient has the same physical origins as the normal pulsars. [ABSTRACT FROM AUTHOR]

Published
2024
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3. The FAST Galactic Plane Pulsar Snapshot Survey – III. Timing results of 30 newly discovered pulsars

Author

Su, W Q, primary, Han, J L, additional, Wang, P F, additional, Yuan, J P, additional, Wang, Chen, additional, Zhou, D J, additional, Wang, Tao, additional, Yan, Yi, additional, Jing, W C, additional, Yang, Z L, additional, Cai, N N, additional, Chen, Xue, additional, Xu, Jun, additional, Xie, Lang, additional, Wang, H G, additional, Xu, R X, additional, and You, X P, additional

Published
2023
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5. Jiamusi pulsar observations – IV. The core-weak pattern of PSR B0329+54

Author

Wang, Tao, Han, J. L., Wang, C., Wang, P. F., and Zhou, D. J.

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

The bright pulsar PSR B0329+54 was previously known for many years to have two emission modes. Sensitive observations of individual pulses reveal that the central component of pulse profile, which is called core component, is found to be very weakened occasionally for some periods and then recovered. This is the newly identified core-weak mode. Based on our long observations of PSR B0329+54 by the Jiamusi 66-m telescope at 2250 MHz, we report here that the profile components of individual pulses, including these for the core and the leading and trailing peaks, are relatedly varying over some periods even before and after the core-weak mode, forming a regular pattern in the phase-vs-time plot for a train of period-folded pulses. The pattern has a similar structure for the core-weak mode with a time scale of 3 to 14 periods. It starts with an intensity brightening at the trailing phase of the core component, and then the core intensity declines to a very low level, as if the core component is drifting out from the normal radiation window within one or two periods. Then the intensity for the trailing components is enhanced, and then the leading component appears at an advanced phase. Such a core-weak mode lasts for several periods. Finally, the core-weak mode ends up with an enhanced intensity at the leading phase for the core component, as if the core gradually comes back and finally stays at the phase of the profile center as it used to., Comment: 10 pages, 9 figures, accepted for publication in MNRAS

Published
2023

7. Radio frequency interference mitigation based on the asymmetrically reweighted penalized least squares and SumThreshold method.

Author

Zeng, Qingguo, Chen, Xue, Li, Xiangru, Han, J L, Wang, Chen, Zhou, D J, and Wang, Tao

Subjects
RADIO interference, LEAST squares, RADIO telescopes, RADIO astronomy, ALGORITHMS
Abstract

As radio telescopes become more sensitive, radio frequency interference (RFI) is becoming more important for interesting signals of radio astronomy. There is a demand for developing an automatic, accurate and efficient RFI mitigation method. Therefore, we have investigated an RFI detection algorithm. First, we introduce an asymmetrically reweighted penalized least squares (ArPLS) method to estimate the baseline more accurately. After removing the estimated baseline, several novel strategies were proposed based on the SumThreshold algorithm for detecting different types of RFI. The threshold parameter in SumThreshold can be determined automatically and adaptively. The adaptiveness is essential for reducing human intervention and for the online RFI processing pipeline. Applications to data from the Five-hundred-meter Aperture Spherical Telescope (FAST) show that the proposed scheme based on ArPLS and SumThreshold is superior to some typically available methods for RFI detection with respect to efficiency and performance. [ABSTRACT FROM AUTHOR]

Published
2021
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