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A new class of X-ray Pulsars ?

L. Stella·S. Mereghetti·G. L. Israel
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Abstract

While the distribution of spin periods of High Mass X-ray Binaries (HMXBs) spans more than four orders of magnitude (69ms - 25min), the few known X-ray pulsars accreting from very low mass companions (<1 Msun) have very similar periods between 5.4 and 8.7s . These pulsars display also several other similarities and they are probably members of a subclass of Low Mass X-ray Binaries (LMXBs) with similar magnetic field (a few 10^11 G), companion stars and, possibly, evolutionary histories. If they are rotating at, or close to, the equilibrium period, their properties are consistent with luminosities of the order of a few 10^35 erg/s. These pulsars might represent the closest members of a subclass of LMXBs characterized by lower luminosities, higher magnetic fields and smaller ages than non-pulsating LMXBs.

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L. Stella, S. Mereghetti, G. L. Israel. 1996-05-11. A new class of X-ray Pulsars ?. https://arxiv.org/abs/astro-ph/9605058

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