A radio-microlensing caustic crossing in B1600+434?
Abstract
First, we review the current status of the detection of strong `external' variability in the CLASS gravitational B1600+434, focusing on the 1998 VLA 8.5-GHz and 1998/9 WSRT multi-frequency observations. We show that this data can best be explained in terms of radio-microlensing. We then proceed to show some preliminary results from our new multi-frequency VLA monitoring program, in particular the detection of a strong feature (~30%) in the light curve of the lensed image which passes predominantly through the dark-matter halo of the lens galaxy. We tentatively interpret this event, which lasted for several weeks, as a radio-microlensing caustic crossing, i.e. the superluminal motion of a micro-arcsec-scale jet-component in the lensed source over a single caustic in the magnification pattern, that has been created by massive compact objects along the line-of-sight to the lensed image.
Cite
@article{arxiv.astro-ph/0004285,
title = {A radio-microlensing caustic crossing in B1600+434?},
author = {L. V. E. Koopmans and A. G. de Bruyn and J. Wambsganss and C. D. Fassnacht},
journal= {arXiv preprint arXiv:astro-ph/0004285},
year = {2007}
}
Comments
8 pages, 3 figures, to appear in Microlensing 2000: A New Era of Microlensing Astrophysics, eds J.W. Menzies and P.D. Sackett, ASP Conference Series