English

A very rapid Extreme Scattering Event in the IDV source 0954+658

Astrophysics 2009-11-07 v1

Abstract

Extreme Scattering Events (ESEs) are dramatic variations of the flux density at Gigahertz frequencies caused by ray path distortions within an isolated inhomogeneity ("plasma lens") in the interstellar medium. These events are characterized by a deep flux density minimum in the light curve with, in some cases, surrounding maxima. The variability time scales range from weeks to months. These phenomena show a strong frequency dependence, in which the variability amplitudes increase with wavelength. During an Intraday Variability (IDV) monitoring project (March 2000), a feature resembling an ESE-like event appeared in the variable light curve of 0954+658, however with a time scale of less than two days. We will discuss this effect and its implications for a better description of the interstellar medium.

Keywords

Cite

@article{arxiv.astro-ph/0110527,
  title  = {A very rapid Extreme Scattering Event in the IDV source 0954+658},
  author = {G. Cimò and T. Beckert and T. P. Krichbaum and L. Fuhrmann and A. Kraus and A. Witzel and J. A. Zensus},
  journal= {arXiv preprint arXiv:astro-ph/0110527},
  year   = {2009}
}

Comments

6 pages, 7 PS files. Accepted for publication in PASA; based on a talk given at the workshop: "AGN variability across the Electromagnetic Spectrum", Sydney 2001