The braking index of millisecond magnetars

Abstract

We make the first measurement of the braking index $n$ of two putative millisecond magnetars born in short gamma-ray bursts. We measure $n=2.9\pm 0.1$ and $n=2.6\pm 0.1$ for millisecond magnetars born in GRB 130603B and GRB 140903A respectively. The neutron star born in GRB 130603B has the only known braking index consistent with the fiducial $n=3$ value. This value is ruled out with 99.95\% confidence for GRB 140903A. We discuss possible causes of $n<3$ braking indices in millisecond magnetars, showing that several models can account for the measurement of the braking index in GRB 140903A, while it is more difficult to account for a braking index consistent with $n=3$.

ApJL

References in corpus (8)

• 45 Years of Rotation of the Crab Pulsar
• The Millisecond Magnetar Central Engine in short GRBs
• High resolution numerical-relativity simulations for the merger of binary magnetized neutron stars
• CCOs and the hidden magnetic field scenario
• Rotational evolution of young pulsars due to superfluid decoupling
• A New, Low Braking Index For the LMC Pulsar B0540-69
• The Braking Index of a Radio-quiet Gamma-ray Pulsar
• The interpretation of the multi-wavelength afterglow emission of short GRB 140903A

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