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arXiv · 1607.03427

Propeller effect in the transient X-ray pulsar SMC X-2

A. Lutovinov·S. Tsygankov·R. Krivonos·S. Molkov·J. Poutanen
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Abstract

We report the results of the monitoring campaign of the transient X-ray pulsar SMC X-2 performed with the Swift/XRT telescope over the period of 2015 September - 2016 January during the Type II outburst. During this event, the bolometric luminosity of the source ranged from $\simeq10^{39}$ down to several$\times10^{34}$ erg/s. Moreover, we discovered its dramatic drop by a factor of more than 100 below the limiting value of $L_{\rm lim}\simeq4\times10^{36}$ erg/s, which can be interpreted as a transition to the propeller regime. These measurements make SMC X-2 the sixth pulsating X-ray source where such a transition is observed and allow us to estimate the magnetic field of the neutron star in the system $B\simeq3\times10^{12}$ G, which is in agreement with independent results of the spectral analysis.

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A. Lutovinov, S. Tsygankov, R. Krivonos, S. Molkov, J. Poutanen. 2016-07-11. Propeller effect in the transient X-ray pulsar SMC X-2. https://doi.org/10.3847/1538-4357%2F834%2F2%2F209

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