We argue that the bursting, transient X-ray source GRO J1744-28 is a binary consisting of a very low-mass (M≈0.2M\sun), highly evolved giant star that is transferring mass by Roche lobe overflow onto a high-mass (M≈1.8M\sun) neutron star. We explore a picture in which the bursts are due to thermonuclear flashes in matter that has accreted onto the neutron star. We attribute the unusually hard spectra of the bursts and the high burst rate compared to normal Type I X-ray burst sources -- indeed the existence of unstable nuclear burning itself -- to the unusually strong surface magnetic field, Bs≈1×1013 G, of the neutron star.
@article{arxiv.astro-ph/9604089,
title = {GRO J1744-28: Last Gasps of a Dying Low-mass X-ray Binary},
author = {D. Q. Lamb and M. Coleman Miller and R. E. Taam},
journal= {arXiv preprint arXiv:astro-ph/9604089},
year = {2007}
}
Comments
10 pages, plain TeX, submitted on February 9 to ApJ Letters