中文
相关论文

相关论文: Interstellar Plasma Turbulence Spectrum Toward the…

200 篇论文

Our analysis of archival VLBI data of PSR 0834+06 revealed that its scintillation properties can be precisely modelled using the inclined sheet model (Pen & Levin 2014), resulting in two distinct lens planes. These data strongly favour the…

太阳与恒星天体物理 · 物理学 2016-02-17 Siqi Liu , Ue-Li Pen , J-P Macquart , Walter Brisken , Adam Deller

The circumgalactic medium (CGM) is poorly constrained at the sub-parsec scales relevant to turbulent energy dissipation and regulation of multi-phase structure. Fast radio bursts (FRBs) are sensitive to small-scale plasma density…

星系天体物理 · 物理学 2025-07-25 S. K. Ocker , M. Chen , S. P. Oh , P. Sharma

Using new techniques based on the polarimetric fluctuation spectrum, the fluctuation behaviour of the polarization of individual pulses is examined in three pulsars that show drifting subpulses, allowing various aspects of the fluctuations…

天体物理学 · 物理学 2009-11-10 R. T. Edwards

(Abridged) This paper reports new Very Large Array (VLA) and Very Long Baseline Array (VLBA) observations of the extragalactic source B1849+005 at frequencies between 0.33 and 15 GHz and the re-analysis of archival VLA observations at 0.33,…

天体物理学 · 物理学 2009-11-10 Joseph Lazio

We report the B band optical observations of an old (17.5 Myr) radiopulsar PSR B0950+08 obtained with the Suprime-Cam at the Subaru telescope. We detected a faint object, B=27.07(16). Within our astrometrical accuracy it coincides with the…

A new technique has been developed to remove the ionosphere's distorting effects from low frequency VLBI data. By fitting dispersive and non-dispersive components to the phases of multi-frequency data, the ionosphere can be effectively…

Understanding the evolution of pulsar dispersion measures is vital to high precision timing experiments, as well as astrometric experiments to determine pulsar positions and proper motions. In this work, we present a novel approach to…

高能天体物理现象 · 物理学 2025-08-22 Daniel Baker , Ue-Li Pen

We investigated HI absorption toward a single pulsar, PSR J1644$-$4559, and its variability over timescales from days to years, using Murriyang, CSIRO's Parkes Radio Telescope. Our 19 epochs of spectral observations, spanning 1.2 years with…

Individual radio pulses from a pulsar are directly linked to the underlying emission processes and the associated magnetic field geometry within its magnetosphere. Thus, single-pulse studies across frequencies can provide crucial insights…

高能天体物理现象 · 物理学 2026-01-27 Shyam S. Sharma , Tetsuya Hashimoto , Tomotsugu Goto , Sanjay Kudale , Sujin Eie , Simon C. -C. Ho

We present multi-frequency scatter broadening evolution of 29 pulsars observed with the LOw Frequency ARray (LOFAR) and Long Wavelength Array (LWA). We conducted new observations using LOFAR Low Band Antennae (LBA) as well as utilized the…

高能天体物理现象 · 物理学 2019-06-26 M. A. Krishnakumar , Yogesh Maan , Bhal Chandra Joshi , P. K. Manoharan

The dynamic spectrum of a radio pulsar is an in-line digital hologram of the ionised interstellar medium. It has previously been demonstrated that such holograms permit image reconstruction, in the sense that one can determine an…

天体物理学 · 物理学 2009-11-13 Mark Walker , Leon Koopmans , Dan Stinebring , Willem van Straten

The remarkable rapid variations in radio flux density and polarization of the quasar PKS 0405-385 observed in 1996 are subject to a correlation analysis, from which characteristic time scales and amplitudes are derived. The variations are…

天体物理学 · 物理学 2009-11-07 Barney J. Rickett , Lucyna Kedziora-Chudczer , David L. Jauncey

The mode switching phenomenon of PSR B0329+54 is investigated based on the long-term monitoring from September 2003 to April 2009 made with the Urumqi 25m radio telescope at 1540 MHz. At that frequency, the change of relative intensity…

太阳与恒星天体物理 · 物理学 2015-05-28 J. L. Chen , H. G. Wang , N. Wang , A. Lyne , Z. Y. Liu , A. Jessner , J. P. Yuan , M. Kramer

Turbulent dynamics generate random fluctuations in density and velocity in the Interstellar Medium (ISM) of spiral and dwarf galaxies. Observationally, H~{\sc i} 21-cm radiation provides a good probe of these stochastic processes and helps…

星系天体物理 · 物理学 2018-05-30 Meera Nandakumar

The long-term rotational evolution of the old, isolated pulsar, PSR B0950+08 is intriguing in that its spin-down rate displays sinusoidal-like oscillations due to alternating variations, both in magnitude and sign, of the second time…

高能天体物理现象 · 物理学 2022-12-15 Erbil Gügercinoğlu , Elif Köksal , Tolga Güver

HI spatial power spectra (PS) were determined for a sample of 24 nearby dwarf irregular galaxies selected from the LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes - The HI Nearby Galaxy Survey) sample. The two-dimensional…

宇宙学与河外天体物理 · 物理学 2015-06-05 Hong-Xin Zhang , Deidre A. Hunter , Bruce G. Elmegreen

We have surveyed 68 deg^2 along the Galactic Plane for single, dispersed radio pulses. Each of 3027 independent pointings was observed for 68 s using the Arecibo telescope at 430 MHz. Spectra were collected at intervals of 0.5 ms and…

天体物理学 · 物理学 2009-10-30 D. J. Nice

We report on a Hubble Space Telescope detection of the nearby, old pulsar B0950+08 ($d\simeq 262$ pc, spin-down age 17.5 Myr) in two far-ultraviolet (FUV) bands. We measured the mean flux densities $\bar{f}_\nu = 109\pm 6$ nJy and $83\pm…

高能天体物理现象 · 物理学 2017-12-06 G. G. Pavlov , B. Rangelov , O. Kargaltsev , A. Reisenegger , S. Guillot , C. Reyes

We observed the young ($\sim 1700$ yrs) pulsar PSR B0540-69 in the near-ultraviolet (UV) for the first time with the Space Telescope Imaging Spectrograph (STIS) aboard the {\em Hubble Space Telescope}. Imaging observations with the NUV- and…

The rare and conspicuous flux density variations of some radio sources (extragalactic and pulsars) for periods of weeks to months have been denoted Extreme Scattering Events (ESE's) by Fiedler et al. (1987). Presently, there is no…

天体物理学 · 物理学 2009-11-13 Murad Hamidouche , Jean-Francois Lestrade