2001/03/09 by Mallory S. E. Roberts, M. S. Roberts, Peter F. Michelson +17
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #High-pressure geophysics and materials #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0103140
19 pages, 14 figures, accepted to the Astrophysical Journal
arxiv created 2001/03/09 · openalex publication_date 2001/03/09 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We report on ASCA, RXTE, and archival observations of the high mass X-ray binary pulsar 4U1907+09. Spectral measurements of the absorption and flux were made at all phases of the X-ray pulsar orbit, including the first spectral measurements of an extended period of low flux during two of the ASCA observations. We find that a simple spherical wind model can fit the time averaged light curve as measured by the RXTE ASM, but does not fit the observed changes in the absorption column or account for the existence of the phase-locked secondary flare. An additional model component consisting of a trailing stream can account for the variations in column depth. However, these models favor a high inclination angle for the system, suggesting a companion mass more consistent with an identification as a Be-star. In this case an equatorially enhanced wind and inclined neutron star orbit may be a more appropriate interpretation of the data.