The Sleeping Giant, NuSTAR Observations of magnetar SGR 1806-20
Abstract
Magnetars are a subclass of isolated neutron stars known for their extreme transient behavior, on different time-scales ranging from milliseconds to years. On the seconds time-scales, almost all magnetars have been observed to enter bursting episodes where they emit 10s to 100s of short (~0.1 s), bright (1.0e37-1.0e41 erg), hard X-ray bursts within the span of days to weeks. These episodes are usually accompanied by an alteration of the source persistent X-ray emission, during which the spectral and temporal properties of the magnetar change drastically. The source persistent X-ray flux increases, occasionally by as many as three orders of magnitude, while its timing properties vary, either in the form of a glitch or a more gradual change in the spin-down rate. Three magnetars have so far shown a Gaint Flare, an immense flare of energy (E~1.0e46 erg) lasting for few hundred seconds. I will report on the analysis of 5 NuSTAR observations of SGR 1806-20, the last magnetar to emit a giant flare (December 2004), taken between April 2015 to April 2016. I will discuss the long-term temporal and spectral behavior of the source from 1993 to 2016, i.e., prior, during, and after its major bursting bursting episode of 2004.
- Publication:
-
American Astronomical Society Meeting Abstracts #231
- Pub Date:
- January 2018
- Bibcode:
- 2018AAS...23133306Y