Article
Astronomy & Astrophysics
Tao Wang, J. L. Han, C. Wang, P. F. Wang, D. J. Zhou
Summary: The bright pulsar PSR B0329+54 has two emission modes, with the newly identified core-weak mode showing a weakening of the central component of the pulse profile. Observations indicate that individual pulse components, including the core and leading and trailing peaks, exhibit related variations forming a regular pattern in the phase-time plot. This pattern lasts for several periods, involving changes in intensity and phase of the core and other components.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Z. Y. Tu, R. Yuen, Z. G. Wen, N. Wang, W. M. Yan, J. P. Yuan, J. L. Chen, H. G. Wang
Summary: This study investigates the properties of the low emission mode in PSR B0329+54, and finds that it is characterized by a drop in intensity in the central component. The low mode is related to the two emission modes, and the integrated profile of the low mode is unique. The occurrence rate of low modes is higher in the normal emission mode, and the intensity drop in the central component is separated from the emission of the other two components.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Daniel J. Reardon, William A. Coles
Summary: Density fluctuations in the ionized interstellar medium affect radio pulsar observations, but a new technique using dynamic spectrum of intensity scintillations can recover variations in dispersive delays. This technique requires knowledge of pulsar velocity and scattering region. It can be used to search for extreme scattering events and distinguish true dispersion variations from pulse shape changes. The technique is successfully demonstrated by recovering an extreme scattering event in PSR J1603-7202.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Itzhak Goldman
Summary: This paper examines the observational structure function of the scintillations of the radio pulsar PSR B0950+08 and proposes that the deviations observed are consistent with both Kolmogorov turbulence and compressive turbulence, which differ in terms of the depth of turbulent regions. The estimates support the presence of extremely thin, ionized scattering screens in the local interstellar cloud, as proposed a decade ago.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Ziwei Wu, William A. Coles, Joris P. W. Verbiest, Krishnakumar Moochickal Ambalappat, Caterina Tiburzi, Jean-Mathias Griessmeier, Robert A. Main, Yulan Liu, Michael Kramer, Olaf Wucknitz, Nataliya Porayko, Stefan Oslowski, Ann-Sofie Bak Nielsen, Julian Y. Donner, Matthias Hoeft, Marcus Brueggen, Christian Vocks, Ralf-Juergen Dettmar, Gilles Theureau, Maciej Serylak, Vladislav Kondratiev, James W. McKee, Golam M. Shaifullah, Ihor P. Kravtsov, Vyacheslav V. Zakharenko, Oleg Ulyanov, Olexandr O. Konovalenko, Philippe Zarka, Baptiste Cecconi, Leon V. E. Koopmans, Stephane Corbel
Summary: Interstellar scattering is used to probe the ionized interstellar medium and can cause corruptions in pulsar timing experiments. Intensity scintillation and pulse broadening are two types of ISS phenomena caused by small-scale electron density fluctuations. While the Kolmogorov spectral exponent can model the electron density power spectrum, the inhomogeneity in the scattering region affects the pulse broadening behavior.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Fang Xi Lin, Hsiu-Hsien Lin, Jing Luo, Robert Main, James McKee, Ue-Li Pen, Dana Simard, Marten H. van Kerkwijk
Summary: Propagation effects and intrinsic profile changes can lead to timing variability in pulsars. The pulsar PSR J1713+0747 has experienced two 'dip' events in its dispersion measure (DM) series, which are consistent and show transient pulse profile variations. However, these variations are different from what is expected from lensing due to a corrugated sheet, suggesting the need for higher resolution data for further study.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Yonghua Xu, Xun Shi, Kejia Lee, Longfei Hao, Zhixuan Li, Min Wang, Jianping Yuan, Heng Xu, Ziwei Wu, Jinchen Jiang, Yuxiang Huang, Bojun Wang, Faxin Shen, Shuo Cao
Summary: By studying the scintillation phenomena of pulsar PSR J0835-4510, this paper reveals the existence of parabolic arc structures in the secondary spectrum and proposes an anisotropic scattering screen model to explain their morphology and time variation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
J. Askew, D. J. Reardon, R. M. Shannon
Summary: Long-term studies of binary millisecond pulsars (MSPs) provide precise tests of strong-field gravity and measure neutron-star masses. The scintillation of PSR J1909-3744 was studied using observations from the 64-m Parkes Radio Telescope over a 13-year period. The statistics of the ionized interstellar medium (IISM) remained constant, and a slightly anisotropic model was preferred.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Stefan Oslowski, Mark A. Walker
Summary: A pulsar dynamic spectrum is a digital hologram that encodes information on the propagation paths of signals. We present a new method, called H-FISTA, for phase retrieval in pulsar spectroscopy using the Fast Iterative Shrinkage Thresholding Algorithm. Our algorithm obtains sparse models of the wavefield in a hierarchical approach, leading to a fully dense model that allows the discovery of faint signals. The performance of our method is demonstrated on synthetic test cases and real data.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
L. S. Oswald, A. Karastergiou, S. Johnston
Summary: The conventional model of pulsar polarization fails to explain certain properties observed in the population of radio pulsars, such as frequency evolution of polarization, deviations in linear polarization angles, and presence of circular polarization features. To address this, the partial-coherence model is presented as an explanation for the co-occurrence of these features and a source of circular polarization in radio pulsar profiles. The mathematical principles and its ability to explain observed features on both population and individual pulsar level are described, highlighting its importance in understanding pulsar geometries and radio emission.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
E. Gugercinoglu, M. Y. Ge, J. P. Yuan, S. Q. Zhou
Summary: This study presents timing solutions from observations of gamma-ray pulsars, identifying new glitches, analyzing their properties, and obtaining important information about the structure of neutron stars. The observed results are in qualitative agreement with the theoretical predictions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Bobakov, A. Karpova, S. Zharikov, A. Yu Kirichenko, Yu A. Shibanov, D. A. Zyuzin
Summary: This article presents the optical spectroscopy results of three binary millisecond pulsars, showing that the companions of J0621+2514 and J2317+1439 are DA-type white dwarfs with relatively high temperatures of 8600 +/- 200 and 9600 +/- 2000 K, respectively, while the companion of J2302+4442 is a cooler DA-type white dwarf with a temperature below 6000 K.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
J. Dyks
Summary: Radio pulsars display unexplained phenomena in their pulse profiles, such as the core-cone structure and frequency evolution. The author proposes that these phenomena can be explained through the geometric properties of inverse Compton scattering. The observed bifurcated components can be interpreted as magnified microbeams of curvature radiation that have been upshifted in frequency and preserved in width by beam-copying scattering.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
J. Dyks
Summary: This study reveals that the complex behavior of single radio pulses from pulsars is mainly a result of the sector structure of the observed relatively simple radio beam, leading to a diversity of pulsation modes and nulling. The research also demonstrates that the classical drift-period-folded patterns are caused by the slow drift of the sector beam.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Lorenzo Iorio
Summary: This study discusses the method of using the Lense-Thirring effect to measure or constrain the moment of inertia in a double pulsar system. The research results show that the effects can be accurately tested by determining subtle variations at different scales.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Z. G. Wen, R. Yuen, N. Wang, Z. Y. Tu, Z. Yan, J. P. Yuan, W. M. Yan, J. L. Chen, H. G. Wang, Z. Q. Shen, Z. Wang, W. J. Yang, X. F. Duan, Y. F. Zhang, Y. B. Wang, J. W. Mao
Summary: This study reports detection of bright pulses from PSR B0031-07, revealing specific distribution patterns of peak flux density and interval times, as well as well-defined quasi-periodicities in some of the detected pulses.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Zhichen Pan, Lei Qian, Xiaoyun Ma, Kuo Liu, Lin Wang, Jintao Luo, Zhen Yan, Scott Ransom, Duncan Lorimer, Di Li, Peng Jiang
Summary: The discovery of 24 pulsars in 15 globular clusters using FAST includes the first detections in M2, M10, and M14. Most of these pulsars are confirmed or likely members of binary systems, with only a few isolated. These findings contribute important data for studying pulsars within clusters.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Astronomy & Astrophysics
J. L. Han, Chen Wang, P. F. Wang, Tao Wang, D. J. Zhou, Jing-Hai Sun, Yi Yan, Wei-Qi Su, Wei-Cong Jing, Xue Chen, X. Y. Gao, Li-Gang Hou, Jun Xu, K. J. Lee, Na Wang, Peng Jiang, Ren-Xin Xu, Jun Yan, Heng-Qian Gan, Xin Guan, Wen-Jun Huang, Jin-Chen Jiang, Hui Li, Yun-Peng Men, Chun Sun, Bo-Jun Wang, H. G. Wang, Shuang-Qiang Wang, Jin-Tao Xie, Heng Xu, Rui Yao, Xiao-Peng You, D. J. Yu, Jian-Ping Yuan, Rai Yuen, Chun-Feng Zhang, Yan Zhu
Summary: The GPPS survey, utilizing the sensitive FAST radio telescope, aims to discover pulsars within the Galactic plane with a focus on inner Galaxy regions. The survey has successfully discovered 201 pulsars, including faint ones undetectable by other telescopes and those challenging current models for Galactic electron density distribution.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Zhichen Pan, Xiao-Yun Ma, Lei Qian, Lin Wang, Zhen Yan, Jin-Tao Luo, Scott M. Ransom, Duncan R. Lorimer, Peng Jiang
Summary: Researchers have discovered three new pulsars in the globular cluster NGC 6517 using the FAST telescope, with slightly different spin periods and dispersion measures compared to previously known pulsars. They have also updated the timing solutions of known isolated pulsars in the cluster, showing that these new pulsars are close to each other on the sky and near the optical core of NGC 6517. The discoveries were made possible by the high sensitivity of FAST and a new algorithm for identifying candidate signals.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2021)
Article
Environmental Sciences
Lue Chen, Jinsong Ping, Jianfeng Cao, Xiang Liu, Na Wang, Zhen Wang, Ping Zhu, Mei Wang, Haijun Man, Fei Fan, Weitao Lu, Jing Sun, Songtao Han
Summary: A novel method based on local correlation of segmented modeling is proposed for retrieving high accuracy radio Doppler frequency from an open-loop radio link signal. Simulations confirm the validity of this method, showing better accuracy than the digital baseband receiver at CDSS. The proposed method benefits Chinese deep space exploration missions and planetary radio science experiments.
Review
Astronomy & Astrophysics
Jun Li, Na Wang, Zhiyong Liu, Yining Song, Ning Li, Lingming Xu, Jili Wang
Summary: The control system is the central control unit of the radio telescope for high-precision astronomical observation. The architecture of the control system is crucial for stability and maintainability, and the middleware framework can provide valuable reference for design of other radio telescope control systems.
ADVANCES IN ASTRONOMY
(2021)
Article
Astronomy & Astrophysics
Yining Song, Zhiyong Liu, Na Wang, Jun Li, Rai Yuen
Summary: The PPSD algorithm is proposed to mitigate transient radio frequency interference in pulsar observations by identifying pulsar phase and extracting pulse profile. It sets a threshold based on statistics to label transient RFI and substitute it with white Gaussian noise, resulting in improved signal-to-noise ratio of pulsar observations.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Z. Wang, Z. G. Wen, J. P. Yuan, N. Wang, J. L. Chen, W. M. Yan, R. Yuen, X. F. Duan, B. B. Xiang, D. L. He
Summary: A detailed study of single-pulse emission from pulsar J2048-1616 was conducted using the Parkes 64 m radio telescope at different frequencies, revealing the presence of nulling, subpulse drifting, and quasiperiodic modulations. The pulsar exhibits well-resolved emission components and periodic modulations, which are significantly dependent on time.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Zhen Yan, Zhi-chen Pan, Scott M. Ransom, Duncan R. Lorimer, Lei Qian, Pei Wang, Zhi-qiang Shen, Di Li, Peng Jiang, Jin-Tao Luo, Jie Liu, Zhi-peng Huang
Summary: The discovery of the first radio pulsar associated with NGC 6712, an eclipsing black widow pulsar, J1853-0842A, shows a low mass companion and pulsar signal eclipsing. Follow-up timing observations confirmed the association between the pulsar and NGC 6712.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
S. Q. Wang, J. B. Wang, N. Wang, J. M. Yao, G. Hobbs, S. Dai, F. F. Kou, C. C. Miao, D. Li, Y. Feng, S. J. Dang, D. H. Wang, P. Wang, J. P. Yuan, C. M. Zhang, L. Zhang, S. B. Zhang, W. W. Zhu
Summary: In this study, we reported an exceptionally bright observation of PSR J1720-0533 using FAST, revealing quasi-periodic pulse emission variations during the eclipse that may be caused by plasma lensing. Additionally, we found that the linear polarization of the pulsar disappears before the eclipse, and pulse scattering may play a significant role in the eclipse of PSR J1720-0533.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Astronomy & Astrophysics
Jie Liu, Hong-Guang Wang, Zhi-Qiang Shen, Zhen Yan, Hao Tong, Zhi-Peng Huang, Ru-Shuang Zhao
Summary: This paper reports two new glitches of PSR B1822-09 detected at the Shanghai Tian Ma Radio Telescope, and analyzes the changes in the integrated mean pulse profiles before and after the glitches, as well as the relationship between glitch sizes and waiting times.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Zhi-Peng Huang, Zhen Yan, Zhi-Qiang Shen, Hao Tong, Jian-Ping Yuan, Lin Lin, Rong-Bing Zhao, Ya-Jun Wu, Jie Liu, Rui Wang, Xiao-Wei Wang
Summary: In this study, we conducted 926 days of observations on XTE J1810-197 using the Shanghai Tian Ma Radio Telescope, and found changes in its integrated profiles and spin frequency. By using the piecewise fitting method, we obtained the spin frequency and spin-frequency derivatives, and observed changes in flux densities. We also discovered a correlation between the emission heights of XTE J1810-197 and the degree of magnetic field twisting.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Dong Zhang, Rong-Bing Zhao, Zhen Yan, Wei-Hua Shang-Guan, Qian Ye, Zhi-Qiang Shen, Qing-Hui Liu, Jin-Qing Wang, Li Fu, Chu-Yuan Zhang, Dong-Fang Song, Si-Yu Liu
Summary: This paper describes the design and implementation of the TMRT Active Surface System Control Software (TASCS), which enables real-time automated adjustment of the primary reflector through remote centralized control. TASCS has been successfully deployed on the TMRT and played a crucial role in Event Horizon Telescope observations.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Rukiye Rejep, N. Wang, W. M. Yan, Z. G. Wen
Summary: This paper investigates the emission properties of PSR J1727-2739, which shows both nulling and subpulse drifting. The study reveals two distinct drift modes with vertical drift band separations consistent with earlier studies. PSR J1727-2739 exhibits changes in drift periodicity and drift rate variations between components, providing a unique opportunity to investigate the physical mechanism responsible for these phenomena.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Xiang-Han Cui, Cheng-Min Zhang, Shuang-Qiang Wang, Jian-Wei Zhang, Di Li, Bo Peng, Wei-Wei Zhu, Na Wang, Richard Strom, Chang-Qing Ye, De-Hua Wang, Yi-Yan Yang
Summary: The study demonstrates that repeating and non-repeating FRBs exhibit statistical differences, suggesting different origins. By using pulse width and radio luminosity as statistical variables, it is possible to infer that the two classes of FRBs have distinct origins.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)