Spectral Evolution of weak bursts from SGR 1806-20 observed with INTEGRAL

Abstract

We report on bursts from the Soft Gamma-Ray Repeater SGR 1806--20 detected with INTEGRAL in October 2003, during a period of moderate activity of the source. The spectral and temporal properties of 21 short bursts are consistent with those found in previous observations, even if these bursts are among the faintest observed in the 15-200 keV range from this source. During some of the bursts a clear spectral evolution is visible. The data also show, for the first time, evidence for a hardness-intensity anti-correlation within SGR 1806--20 bursts.

Accepted for publication in Astronomy & Astrophysics Letters

References in corpus (5)

• ISGRI: the INTEGRAL Soft Gamma-Ray Imager
• The Integral Burst Alert System (IBAS)
• Temporal and Spectral Characteristics of Short Bursts from the Soft Gamma Repeaters 1806-20 and 1900+14
• Precise Chandra Localization of the Soft Gamma-ray Repeater SGR 1806-20
• Observations of giant outbursts from Cygnus X-1

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