The first Suzaku observation of SGR 1806-20

TL;DR

This paper reports the first Suzaku observation of SGR 1806-20 after its giant flare, revealing a near pre-flare flux level, a soft spectrum, and ongoing activity with short bursts, providing insights into magnetar behavior.

Contribution

It presents the first Suzaku data on SGR 1806-20 post-flare, analyzing its spectral properties and activity in the context of magnetar models.

Findings

Flux close to pre-flare levels

Presence of short bursts during observation

Soft broadband spectrum observed

Abstract

The soft gamma-ray repeater SGR 1806-20 has been attracting a lot of attention owing to the fact that in December 2004 it emitted the most powerful giant flare ever observed. Here we present the results of the first Suzaku observation of SGR 1806-20, that seems to have reached a state characterized by a flux close to the pre-flare level and by a relatively soft spectrum. Despite this, the source remained quite active, as testified by several short bursts observed by Suzaku. We discuss the broadband spectral properties of SGR 1806-20 in the context of the magnetar model, considering its recent theoretical developments.