The First MAXI/GSC View of Galactic Magnetars
Abstract
Magnetars are strongly magnetized neutron stars with surface magnetic fields of ∼ 10^14 G. Based on observational and theoretical studies, 5 soft gamma repeaters and 9 anomalous X-ray pulsars are generally known as the galactic magnetars. Their quiescent emission consists of a thermal component (<10 keV), and a hard power law component with a very hard index of 1 (> 10 keV; e.g., Enoto et al. 2010). Some of them presented a flux increasing by a factor of 2-3 accompanied by high burst activities and/or enhanced emission with unusual spectral properties (e.g., Kaneko et al. 2010). Their continuous monitoring is crucial, since comparisons of properties between low and high flux phases give useful information in order to reveal radiation mechanisms. Thanks to a wide field of view and a better sensitivity than RXTE by a factor of a few in a 2-30 keV range of the MAXI/GSC, it is suitable for this purpose. We analyzed the galactic magnetars, and detected at least AXP 4U 0142+614 (∼3 mCrab; >10 sigma) and AXP 1E 1547-5408 (∼1.5 mCrab; >14 sigma) using 1 and 4 week data, respectively. In this talk, we will report the first MAXI/GSC view of the galactic magnetars on long-term variability.
- Publication:
-
The First Year of MAXI: Monitoring Variable X-ray Sources
- Pub Date:
- December 2010
- Bibcode:
- 2010fym..confP..29N