Serendipitous VLBI detection of rapid, large-amplitude, intraday variability in QSO 1156 295 - AstrophysicsReportar como inadecuado




Serendipitous VLBI detection of rapid, large-amplitude, intraday variability in QSO 1156 295 - Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We report a serendipitous detection of rapid, large amplitude flux densityvariations in the highly core-dominated, flat-spectrum radio quasar 1156+295during an observing session at the Very Long Baseline Array VLBA. The sourcewas observed as a part of the MOJAVE survey programme with the VLBA at 15 GHzon February 5, 2007. Large amplitude variability in the correlated fluxdensity, unexplainable in terms of the source structure, was first discoveredwhile processing the data, and later confirmed by calibrating the antenna gainsusing 24 other sources observed in the experiment. The source shows variationsin the correlated flux density as high as 40% on a timescale of only 2.7 hours.This places 1156+295 between the classical IDV sources and the so-calledintra-hour variables. The observed variability timescale and the modulationindex of 13% are consistent with interstellar scintillation by a nearby, highlyturbulent scattering screen. The large modulation index at 15 GHz implies ascattering measure that is atypically high for a high galactic latitude sourcesuch as 1156+295.



Autor: T. Savolainen 1, Y. Y. Kovalev 1 and 2 1 Max-Planck-Institut fuer Radioastronomie, Bonn, Germany, 2 Astro Space Center of Lebedev

Fuente: https://arxiv.org/







Documentos relacionados