Identifying the formation mechanism of redback pulsars

Abstract

We analyse the evolution of close binary systems containing a neutron star that lead to the formation of redback pulsars. Recently there has been some debate on the origin of such systems and the formation mechanism of redbacks may still be considered as an open problem. We show that the operation of a strong evaporation mechanism, starting from the moment when the donor star becomes fully convective (or alternatively since the formation of the neutron star by accretion induced collapse), produces systems with donor masses and orbital periods in the range corresponding to redbacks with donors appreciably smaller than their Roche lobes, i.e., they have low filling factors (lower than $0.75$). Models of redback pulsars can be constructed assuming the occurrence of irradiation feedback. They have been shown to undergo cyclic mass transfer during the epoch at which they attain donor masses and orbital periods corresponding to redbacks, and stay in quasi-Roche lobe overflow conditions with {\it high} filling factors. We show that, if irradiation feedback occurs and radio ejection inhibits further accretion onto the neutron star after the first mass transfer cycle, the redback systems feature {\it high} filling factors. We suggest that the filling factor should be considered as a useful tool for discriminating among those redback formation mechanisms. We compare theoretical results with available observations, and conclude that observations tend to favour models with high filling factors.

7 pages, 3 figures, 2 tables. Accepted for publication in MNRAS

References in corpus (20)

• Shapiro delay measurement of a two solar mass neutron star
• The ATNF Pulsar Catalogue
• A Radio Pulsar/X-ray Binary Link
• Eight New Millisecond Pulsars in NGC 6440 and NGC 6441
• Discovery of PSR J1227-4853: A transition from a low-mass X-ray binary to a redback millisecond pulsar
• Optical spectroscopy and demographics of redback millisecond pulsar binaries
• A 1.4-GHz Arecibo Survey for Pulsars in Globular Clusters
• Long-term observations of the pulsars in 47 Tucanae. I. A study of four elusive binary systems
• Gamma-ray Timing of Redback PSR J2339-0533: Hints for Gravitational Quadrupole Moment Changes
• GBT Discovery of Two Binary Millisecond Pulsars in the Globular Cluster M30
• Optical Counterparts of Two Fermi Millisecond Pulsars: PSR J1301+0833 and PSR J1628-3205
• An active, asynchronous companion to a redback millisecond pulsar
• The High Time Resolution Universe Survey - XI. Discovery of five recycled pulsars and the optical detectability of survey white dwarf companions
• A puzzling millisecond pulsar companion in NGC 6266
• The Quasi-Roche lobe overflow state in the evolution of Close Binary Systems containing a radio pulsar
• Face changing companion of the redback millisecond pulsar PSR J1048+2339
• Formation of redbacks via accretion induced collapse
• PSR J1306--40: An X-ray Luminous Redback with an Evolved Companion
• The 26.3-hr orbit and multi-wavelength properties of the "redback" millisecond pulsar PSR J1306-40
• Evolution of redback radio pulsars in globular clusters

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• Stellar Evolution in Close Binaries: Processes and Outcomes
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