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arXiv · 1501.01054

Reverse Shock Emission and Ionization Break Out Powered by Post-merger Millisecond Magnetars

Ling-Jun Wang·Zi-Gao Dai·Yun-Wei Yu
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Abstract

There is accumulating evidence that at least a fraction of binary neutron star mergers result in rapidly spinning magnetars, with subrelativistic neutron-rich ejecta as massive as a small fraction of solar mass. The ejecta could be heated continuously by the Poynting flux emanated from the central magnetars. Such Poynting flux could become lepton-dominated so that a reverse shock develops. It was demonstrated that such a picture is capable of accounting for the optical transient PTF11agg (Wang & Dai 2013b). In this paper we investigate the X-ray and ultraviolet (UV) radiation as well as the optical and radio radiation studied by Wang & Dai (2013b). UV emission is particularly important because it has the right energy to ionize the hot ejecta at times $t\lesssim 600$ s. It is thought that the ejecta of binary neutron star mergers are a remarkably pure sample of r-process material, about which our understanding is still incomplete. In this paper we evaluate the possibility of observationally determining the bound-bound and bound-free opacities of the r-process material by timing the X-ray, UV, and optical radiation. It is found that these timings depend on the opacities weakly and therefore only loose constraints on the opacities can be obtained.

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Ling-Jun Wang, Zi-Gao Dai, Yun-Wei Yu. 2015-01-06. Reverse Shock Emission and Ionization Break Out Powered by Post-merger Millisecond Magnetars. https://doi.org/10.1088/0004-637x%2F800%2F2%2F79

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