Structure in the radio counterpart to the 2004 Dec 27 giant flare from SGR 1806-20

Abstract

On Dec 27, 2004, the magnetar SGR 1806-20 underwent an enormous outburst resulting in the formation of an expanding, moving, and fading radio source. We report observations of this radio source with the Multi-Element Radio-Linked Interferometer Network (MERLIN) and the Very Long Baseline Array (VLBA). The observations confirm the elongation and expansion already reported based on observations at lower angular resolutions, but suggest that at early epochs the structure is not consistent with the very simplest models such as a smooth flux distribution. In particular there appears to be significant structure on small angular scales, with ~10% of the radio flux arising on angular scales <100 milliarcsec. This structure may correspond to localised sites of particle acceleration during the early phases of expansion and interaction with the ambient medium.

arXiv commentAccepted for publication as a letter in MNRAS

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Cited by in corpus (9)

• Magnetars: the physics behind observations
• The Prelude to and Aftermath of the Giant Flare of 2004 December 27: Persistent and Pulsed X-ray Properties of SGR 1806-20 from 1993 to 2005
• The Caltech-NRAO Stripe 82 Survey (CNSS) Paper I: The Pilot Radio Transient Survey In 50 deg${}^2$
• Magnetar outbursts: an observational review
• XMM-Newton view of Swift J1834.9-0846 and its Magnetar Wind Nebula
• On the Extended Emission Around the Anomalous X-ray Pulsar 1E 1547.0-5408
• Numerical Modeling of the Radio Nebula from the 2004 December 27 Giant Flare of SGR 1806-20
• The Giant Flare from SGR 1806-20 and its Radio Afterglow
• Searching for small-scale diffuse emission around SGR 1806-20