1998/10/03 by G. Dubus, P. A. Charles, Knox S. Long +4 · 2 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Binary number #Binary pulsar #Binary star #Eclipse #Galaxy #Gamma-ray bursts and supernovae #Large Magellanic Cloud #Luminosity #Millisecond pulsar #Neutron star #Orbital period #Physics #Pulsar #Pulsars and Gravitational Waves Research #ROSAT #Roche lobe #Small Magellanic Cloud #Stars #X-ray binary #X-ray pulsar #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.1999.02158.x
accepted for publication in MNRAS
arxiv created 1998/10/03 · openalex publication_date 1999/02/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Using our extensive ROSAT X-ray observations of M33, we confirm a 3.45-d eclipse period for the Einstein source X-7 proposed by Larson & Schulman and discover evidence for a 0.31-s pulse period. The orbital period, pulse period and observed X-ray luminosity are remarkably similar to those of the Small Magellanic Cloud high-mass X-ray binary SMC X-1. We therefore suggest that M33 X-7 is a neutron star high-mass X-ray binary with a 15–40 M⊙ O/B companion and a binary separation of 25–33 R⊙ if the companion is almost filling its Roche lobe.