Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2010-02-18
Monthly Notices of the Royal Astronomical Society, Vol. 405, pp. 1787-1795 (2010)
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
The paper (10 pages) contains 6 colour figures and 2 tables; accepted for publication in MNRAS
Scientific paper
10.1111/j.1365-2966.2010.16551.x
Emission of two short hard X-ray bursts on 2009 June 5 disclosed the existence of a new soft gamma-ray repeater, now catalogued as SGR 0418+5729. After a few days, X-ray pulsations at a period of 9.1 s were discovered in its persistent emission. SGR 0418+5729 was monitored almost since its discovery with the Rossi X-ray Timing Explorer (2-10 keV energy range) and observed many times with Swift (0.2-10 keV). The source persistent X-ray emission faded by a factor 10 in about 160 days, with a steepening in the decay about 19 days after the activation. The X-ray spectrum is well described by a simple absorbed blackbody, with a temperature decreasing in time. A phase-coherent timing solution over the 160 day time span yielded no evidence for any significant evolution of the spin period, implying a 3-sigma upper limit of 1.1E-13 s/s on the period derivative and of 3E+13 G on the surface dipole magnetic field. Phase-resolved spectroscopy provided evidence for a significant variation of the spectrum as a function of the stellar rotation, pointing to the presence of two emitting caps, one of which became hotter during the outburst. Finally, a deep observation of the field of SGR 0418+5729 with the new Gran Telescopio Canarias 10.4-m telescope allowed us to set an upper limit on the source optical flux of i'>25.1 mag, corresponding to an X-ray-to-optical flux ratio exceeding 10000, consistent with the characteristics of other magnetars.
Caraveo Patricia A.
Chaty Sylvain
de Luca Andrea
Esposito Paolo
Gotz Diego
No associations
LandOfFree
Early X-ray and optical observations of the soft gamma-ray repeater SGR 0418+5729 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Early X-ray and optical observations of the soft gamma-ray repeater SGR 0418+5729, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Early X-ray and optical observations of the soft gamma-ray repeater SGR 0418+5729 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-405736