A Compact Extreme Scattering Event Cloud toward AO 0235+164

Senkbeil, C and Ellingsen, S and Lovell, J and Macquart, Jean-pierre and Cimo, Giuseppe and Jauncey, David. 2008. A Compact Extreme Scattering Event Cloud toward AO 0235+164. The Astrophysical Journal. 672: pp. L95-L98.

Source Title

The Astrophysical Journal

DOI

10.1086/527300

ISSN

0004637X

Faculty

Faculty of Science and Engineering

Curtin Institute of Radio Astronomy

Remarks

URI

http://hdl.handle.net/20.500.11937/25433

Collection

Curtin Research Publications

Abstract

We present observations of a rare, rapid, high-amplitude extreme scattering event toward the compact BL Lac object AO 0235+164 at 6.65 GHz. The ESE cloud is compact; we estimate its diameter between 0.09 and 0.9 AU, with a distance of less than 3.6 kpc. Limits on the angular extent of the ESE cloud imply a minimum cloud electron density of ~4 x 10 3 cm -3. Based on the amplitude and timescale of the ESE observed here, we suggest that at least one of the transients reported by Bower et al. may be attributed to ESEs.