2001/10/24 by G. Cimò, Giuseppe Cimò, T. Beckert +5 · 1 citation
Chemistry · Physics and Astronomy · #Amplitude #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Chemistry #Computational physics #Event (particle physics) #Flux (metallurgy) #Interstellar medium #Light curve #Materials science #Maxima #Optics #Path length #Physics #Range (aeronautics) #Scattering #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies #Wavelength #astro-ph
paper · pdf · doi:10.1071/as01097
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
arxiv created 2001/10/24 · openalex publication_date 2002/01/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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 characterised 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.