An X-ray Variable Millisecond Pulsar in the Globular Cluster 47 Tucanae: Closing the Link to Low Mass X-ray Binaries

Abstract

We report the discovery of peculiar X-ray spectral variability in the binary radio millisecond pulsar PSR J0024--7204W in the globular cluster 47 Tucanae. The observed emission consists of a dominant non-thermal component, which is eclipsed for a portion of the orbit, and a thermal component, which appears to be persistent. We propose that the non-thermal X-rays originate in a relativistic intrabinary shock, formed due to interaction between the relativistic particle wind from the pulsar and matter from the main-sequence companion star, while the thermal photons are from the heated magnetic polar caps of the millisecond pulsar. At optical wavelengths, the emission exhibits large-amplitude variations at the orbital period, which can be attributed to heating of one side of the tidally-locked secondary star by the pulsar wind. The observed X-ray and optical properties of PSR J0024--7204W are remarkably similar to those of the low mass X-ray binary and X-ray millisecond pulsar SAX J1808.4--3658 in quiescence. This supports the conjecture that the non-thermal X-ray emission and optical modulations seen in the SAX J1808.4--3658 system in a quiescent state are due to interaction between the wind from a reactivated rotation-powered pulsar and matter from the companion star. The striking similarities between the two systems provide support for the long-sought connection between millisecond radio pulsars and accreting neutron star systems.

arXiv comment8 pages, 4 figures, accepted for publication in the Astrophysical Journal

References in corpus (24)

• Distances and ages of NGC 6397, NGC 6752 and 47 Tuc
• The Neutron Stars of Soft X-Ray Transients
• Observations of 20 millisecond pulsars in 47 Tucanae at 20 cm
• New Evidence for Black Hole Event Horizons from Chandra
• High Resolution X-ray Imaging of a Globular Cluster Core: Compact Binaries in 47Tuc
• Pulsar Polar Cap Heating and Surface Thermal X-Ray Emission II. Inverse Compton Radiation Pair Fronts
• A Deep Chandra Survey of the Globular Cluster 47 Tucanae: Catalog of Point Sources
• An X-ray Nebula Associated with the Millisecond Pulsar B1957+20
• Discovery of short-period binary millisecond pulsars in four globular clusters
• An XMM-Newton study of the 401 Hz accreting pulsar SAX J1808.4-3658 in quiescence
• Chandra Study of a Complete Sample of Millisecond Pulsars in 47Tuc and NGC6397
• X-ray Radiation from the Millisecond Pulsar J0437-4715
• Timing the millisecond pulsars in 47 Tucanae
• The Optical Counterpart to SAX J1808.4-3658 in Quiescence: Evidence of an Active Radio Pulsar?
• A Method for Distinguishing Between Transiently Accreting Neutron Stars and Black Holes, in Quiescence
• Indirect evidence for an active radio pulsar in the quiescent state of the transient ms pulsar SAX J1808.4-3658
• Optical Detection of a Variable Millisecond Pulsar Companion in 47 Tucanae
• A Millisecond Pulsar Optical Counterpart with Large-Amplitude Variability in the Globular Cluster 47 Tucanae
• The eclipsing millisecond pulsar PSR J1740-5340 and its red straggler companion
• Accurate mass ratio and heating effects in the dual-line millisecond binary pulsar in NGC 6397
• The complex Halpha line profile of the bright companion to PSR J1740-5340 in NGC 6397
• Photometry and Spectroscopy of the Optical Companion to the Pulsar PSR J1740-5340 in the Globular Cluster NGC 6397
• A XMM-Newton observation during the 2000 outburst of SAX J1808.4-3658
• Celestial position of the companion of PSR J1740-5340

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• X-ray Observations of XSS J12270-4859 in a New Low State: A Transformation to a Disk-Free Rotation-Powered Pulsar Binary
• Long-term observations of the pulsars in 47 Tucanae. I. A study of four elusive binary systems
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• A Chandra X-ray Observatory Study of PSR J1740--5340 and Candidate Millisecond Pulsars in the Globular Cluster NGC 6397
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