Real-time detection of an extreme scattering event: Constraints on Galactic plasma lenses

• DOI: 10.1126/science.aac7673
• Publication Date: 2016-01-21T20:06:03Z
• Authors: Keith W. Bannister; Jamie Stevens; Artem V. Tuntsov; Mark A. Walker; Simon Johnston; Cormac Reynolds; Hayley Bignall
• Keywords: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA); 0103 physical sciences; FOS: Physical sciences; Astrophysics - High Energy Astrophysical Phenomena; Astrophysics - Astrophysics of Galaxies; 01 natural sciences

Identifying live radio scattering events

Radio emissions from distant quasars are occasionally modified for a few weeks by foreground interstellar plasma, in an extreme scattering event (ESE). Understanding this process has been difficult, because existing techniques do not allow events to be identified fast enough for follow-up before they finish. Bannister et al. developed a radio survey technique that allows ESEs to be identified in real time. After finding their first live ESE, they followed it up with additional radio and optical telescopes. The results constrain the size and density of the plasma and rule out one popular model of ESEs.

Science , this issue p. 354