中文
相关论文

相关论文: Fitting Formula for Flux Scintillation of Compact …

200 篇论文

Comparing the asymmetry coefficients and scintillation indices for observed time variations of the intensity of the radiation of extragalactic sources and the predictions of theoretical models is a good test of the nature of the observed…

天体物理学 · 物理学 2009-11-11 V. I. Shishov , T. V. Smirnova , S. A. Tyul'bashev

We demostrate that the measurement of fluctuations of polarization due to the galactic interstellar scintillations may be used to study the structure of the radiation field at compact radio sources. We develop a mathematical formalism and…

天体物理学 · 物理学 2009-10-31 Mikhail V. Medvedev

Interstellar scintillation can be used to probe transverse sizes of radio sources on scales inaccessible to the nominal resolution of any terrestrial telescope, e.g. $\lesssim 10^{-6}$ arc sec. Methodology is presented that exploits this…

天体物理学 · 物理学 2007-05-23 J. M. Cordes

The search for compact components of strong ($S_{int} \ge 5$ Jy at 102.5 MHz) discrete radio sources from the Pushchino catalogue was carried out using the method of interplanetary scintillation. A total of 3620 sources were examined, and…

高能天体物理现象 · 物理学 2022-07-18 S. A. Tyul'bashev , I. V. Chashei , I. A. Subaev , M. A. Kitaeva

A new method for separating intensity variations of a source's radio emission having various physical natures is proposed. The method is based on a joint analysis of the structure function of the intensity variations and the asymmetry…

天体物理学 · 物理学 2009-11-11 V. I. Shishov , T. V. Smirnova

Intraday Variability of compact extragalactic radio sources can be interpreted as quenched scintillation due to turbulent density fluctuations of the nearby ionized interstellar medium. We demonstrate that the statistical analysis of IDV…

天体物理学 · 物理学 2007-05-23 T. Beckert , L. Fuhrmann , G. Cimo , T. P. Krichbaum , A. Witzel , J. A. Zensus

We derive the distribution of flux density of a compact source exhibiting strong diffractive scintillation. Our treatment accounts for arbitrary spectral averaging, spatially-extended source emission, and the possibility of intrinsic…

天体物理仪器与方法 · 物理学 2012-08-09 Michael D. Johnson , Carl R. Gwinn

The search for long-term variability of compact components of radio sources B0821+394 and B1812+412 over an interval of 10 years was carried out. The LPA LPI radio telescope with an operating frequency of 111 MHz was used for observations.…

高能天体物理现象 · 物理学 2025-04-16 S. A. Tyul'bashev , I. V. Chashei , I. A. Grishanova , G. E. Tyul'basheva , I. A. Subaev

Stars twinkle to the eye through atmospheric turbulence, but planets, because of their larger angular size, do not. Similarly, scintillation due to the local interstellar medium will modulate the radio flux of gamma-ray-burst afterglows and…

天体物理学 · 物理学 2011-03-17 Jeremy Goodman

Observations over the last two decades have shown that a significant fraction of all flat-spectrum, extragalactic radio sources exhibit flux density variations on timescales of a day or less at frequencies of several GHz. It has been…

Refractive interstellar scintillation (RISS) is thought to be the cause behind a variety of phenomena seen at radio wavelengths in pulsars and compact radio sources. Though there is substantial observational data to support several…

天体物理学 · 物理学 2009-10-31 N. D. Ramesh Bhat , A. Pramesh Rao , Yashwant Gupta

Intergalactic scintillation of distant quasars is sensitive to free electrons and therefore complements Ly$\alpha$ absorption line experiments probing the neutral intergalactic medium (IGM). We present a new scheme to compute IGM refractive…

宇宙学与河外天体物理 · 物理学 2015-06-16 A. Pallottini , A. Ferrara , C. Evoli

Stars twinkle because their light propagates through the atmosphere. The same phenomenon is expected on a longer time scale when the light of remote stars crosses an interstellar turbulent molecular cloud, but it has never been observed at…

天体物理仪器与方法 · 物理学 2015-06-12 Farhang Habibi , Marc Moniez , Reza Ansari , Sohrab Rahvar

The shape of the curves defined by the counts of radio sources per unit area as a function of their flux density was one of the earliest cosmological probes. Radio source counts continue to be an area of interest, used to study the relative…

宇宙学与河外天体物理 · 物理学 2015-06-15 Ian Heywood , Matt J. Jarvis , James J. Condon

Intraday variability (IDV) of compact extragalactic radio sources is a complex phenomenon and shows a wavelength dependent mixture of refractive interstellar scintillation (RISS) (dominant at long cm-wavelengths) and source-intrinsic…

天体物理学 · 物理学 2007-05-23 Giuseppe Cimò , L. Fuhrmann , T. P. Krichbaum , T. Beckert , A. Kraus , A. Witzel , J. A. Zensus

We study three quasar radio sources (B1257-326, B1519-273, and J1819+385) that show large amplitude intraday and annual scintillation variability produced by the Earth's motion relative to turbulent-scattering screens located within a few…

天体物理学 · 物理学 2009-11-13 Jeffrey L. Linsky , Barney J. Rickett , Seth Redfield

Compact radio sources such as pulsars and FRBs undergo scintillation in the interstellar medium (ISM) when scattered images interfere at the observer. ``Scintillometry'' refers to the range of techniques to extract astrometric information…

高能天体物理现象 · 物理学 2026-01-30 Dylan L. Jow , Delon Shen

Interplanetary scintillation observations of 48 of the 55 Augusto et al. (1998) flat spectrum radio sources were carried out at 111 MHz using the interplanetary scintillation method on the Large Phased Array (LPA) in Russia. Due to the…

天体物理学 · 物理学 2009-11-11 S. A. Tyul'bashev , A. Pedro

Refractive scintillation effects are powerful techniques for discriminating between different models proposed for the electron density fluctuation spectrum in the ISM. Data from our long-term scintillation study of 18 pulsars in the DM…

天体物理学 · 物理学 2009-10-31 N. D. Ramesh Bhat , Yashwant Gupta , A. Pramesh Rao

The propagation of radio waves from distant compact radio sources through turbulent interstellar plasma in our Galaxy causes these sources to twinkle, a phenomenon called interstellar scintillation. Such scintillations are a unique probe of…

‹ 上一页 1 2 3 10 下一页 ›