Spin period change and the magnetic fields of neutron stars in Be X-ray binaries in the Small Magellanic Cloud

AbstractIn order to understand the progenitor of rotation powered pulsars, we compare them with High-mass X-ray binary (HMXB) pulsars, (or X-ray pulsars), in the Small Magellanic Cloud. The plot of period period vs. period derivative shows that isolated neutron stars could be evolved from HMXBs. The pulsars with long spin period might spin up to 0.001-1 s. The mechanism is a third-body interaction that detaches the donor, leaving an isolated, small period neutron star behind.

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Superstrong magnetic fields of neutron stars in Be X-ray binaries

Proceedings of the International Astronomical Union ◽

10.1017/s1743921319001844 ◽

2018 ◽

Vol 14 (S346) ◽

pp. 135-138

Author(s):

ChangSheng Shi ◽

ShuangNan Zhang ◽

XiangDong Li

Keyword(s):

Magnetic Fields ◽

Neutron Stars ◽

Milky Way ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Emission Lines ◽

Disk Accretion ◽

Superstrong Magnetic Field ◽

X Ray ◽

X Ray Binaries

AbstractA few Be X-ray binaries might constitute a group of special sources because the neutron stars in them may have superstrong magnetic fields. Generally, the neutron stars have long spin periods and some emission lines are shown from the B type star, which is attributed to an equatorial disc. We re-build new dimensionless torque models and obtain the superstrong magnetic fields of the neutron stars in the Be X-ray binaries in Large Magellanic Cloud, Small Magellanic Cloud and Milky Way when the compressed magnetosphere is considered. Although our conclusions are obtained when the disk accretion mode is considered, the results may be applied the Be X-ray binaries with wind accretion mode. SXP1323 and 4U 2206+54, in which the magnetic fields of the NSs may be close to the maximum ‘virial’ value, are the best objects to explore superstrong magnetic field.

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The Relation between Spin and Orbital Periods in HMXBs

Symposium - International Astronomical Union ◽

10.1017/s0074180900194422 ◽

2003 ◽

Vol 214 ◽

pp. 215-217

Author(s):

Q. Z. Liu ◽

X. D. Li ◽

D. M. Wei

Keyword(s):

Magnetic Fields ◽

Orbital Period ◽

Critical Line ◽

High Mass ◽

Orbital Eccentricity ◽

X Ray ◽

Spin Period ◽

Orbital Periods ◽

X Ray Binaries

The relation between the spin period (Ps) and the orbital period (Po) in high-mass X-ray binaries (HMXBs) is investigated. In order for Be/X-ray binaries to locate above the critical line of observable X-ray emission due to accretion, it is necessary for an intermediate orbital eccentricity to be introduced. We suggest that some peculiar systems in the Po − Ps diagram are caused by their peculiar magnetic fields.

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X-ray binaries with neutron stars at different accretion stages

Proceedings of the International Astronomical Union ◽

10.1017/s174392131900125x ◽

2018 ◽

Vol 14 (S346) ◽

pp. 219-227

Author(s):

Konstantin A. Postnov ◽

Alexander G. Kuranov ◽

Lev R. Yungelson

Keyword(s):

Magnetic Fields ◽

Neutron Stars ◽

Orbital Period ◽

Population Synthesis ◽

Circular Orbits ◽

X Ray ◽

Accretion Rates ◽

Supercritical Accretion ◽

Binary Evolution ◽

X Ray Binaries

Abstract. Different accretion regimes onto magnetized NSs in HMXBs are considered: wind-fed supersonic (Bondi) regime at high accretion rates <math/> g s-1, subsonic settling regime at lower <math/> and supercritical disc accretion during Roche lobe overflow. In wind-fed stage, NSs in HMXBs reach equilibrium spin periods P* proportional to binary orbital period Pb. At supercritical accretion stage, the system may appear as a pulsating ULX. Population synthesis of Galactic HMXBs using standard assumptions on the binary evolution and NS formation is presented. Comparison of the model P* – Pb (the Corbet diagram), P* – Lx and Pb – Lx distributions with those for the observed HMXBs (including Be X-ray binaries) and pulsating ULXs suggests the importance of the reduction of P* in non-circular orbits, explaining the location of Be X-ray binaries in the model Corbet diagram, and the universal parameters of pulsating ULXs depending only on the NS magnetic fields.

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Confirmation of six Be X-ray binaries in the Small Magellanic Cloud

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stx181 ◽

2017 ◽

Vol 467 (2) ◽

pp. 1526-1530 ◽

Cited By ~ 3

Author(s):

V. A. McBride ◽

A. González-Galán ◽

A. J. Bird ◽

M. J. Coe ◽

E. S. Bartlett ◽

...

Keyword(s):

Magellanic Cloud ◽

Small Magellanic Cloud ◽

X Ray ◽

X Ray Binaries

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On the geometry of the X-ray emission from pulsars: the changing aspect of the Be/X-ray pulsar SXP348

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz1087 ◽

2019 ◽

Vol 486 (3) ◽

pp. 3248-3258

Author(s):

R Cappallo ◽

S G T Laycock ◽

D M Christodoulou ◽

M J Coe ◽

A Zezas

Keyword(s):

Binary System ◽

Point Source ◽

Geometric Model ◽

Magellanic Cloud ◽

High Mass ◽

Small Magellanic Cloud ◽

X Ray ◽

Spin Period ◽

The Past ◽

Model Fits

ABSTRACT The X-ray source SXP348 is a high-mass X-ray binary system in the Small Magellanic Cloud. Since its 1998 discovery by BeppoSAX, this pulsar has exhibited a spin period of ∼340−350 s. In an effort to determine the orientation and magnetic geometry of this source, we used our geometric model Polestar to fit 71 separate pulse profiles extracted from archival Chandra and XMM-Newton observations over the past two decades. During 2002, pulsations ceased being detectable for nine months despite the source remaining in a bright state. When pulsations resumed, our model fits changed, displaying a change in accretion geometry. Furthermore, in 2006, detectable pulsations again ceased, with 2011 marking the last positive detection of SXP348 as a point source. These profile fits will be released for public use as part of the database of Magellanic Cloud pulsars.

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