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arXiv · 2003.10693

Evidence for magnetar precession in X-ray afterglows of gamma-ray bursts

Arthur G. Suvorov·Kostas D. Kokkotas
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Abstract

Many gamma-ray bursts are followed by periods of extended emission. At least in some cases, the burst afterglow may be powered by a rapidly rotating, highly-magnetised neutron star, which spins down due to electromagnetic and gravitational wave emission. Such a remnant is likely to strongly precess in the early stages of its life, which would lead to modulations in the X-ray luminosity as the triaxiality of the system evolves over time. Using a radiation profile appropriate for a precessing, oblique rotator, we find that Swift-XRT data of a long (080602) and a short (090510) burst matches the model with significantly higher accuracy (mean-square residuals dropping by $\gtrsim 200 \%$ in the early stages of the extended emission) than for an orthogonal rotator. We interpret this as evidence for precession in newborn magnetars.

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Arthur G. Suvorov, Kostas D. Kokkotas. 2020-03-24. Evidence for magnetar precession in X-ray afterglows of gamma-ray bursts. https://doi.org/10.3847/2041-8213/ab8296

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