2006/05/22 by Laura A. Lopez, Herman L. Marshall, Claude R. Canizares +4 · 1 citation
Physics and Astronomy · #Accretion (finance) #Adiabatic process #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Binary star #Compact star #Geometry #Jet (fluid) #Line (geometry) #Mechanics #Neutron star #Physics #Pulsars and Gravitational Waves Research #RADIUS #Roche lobe #Stars #X-ray binary #astro-ph
paper · pdf · doi:10.1086/506174
published as Astrophys.J.650:338-349,2006 · 26 pages, 10 figures, accepted to ApJ
arxiv created 2006/05/22 · openalex publication_date 2006/10/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We test the physical model of the relativistic jets in the Galactic X-ray binary SS 433 proposed in our previous paper using additional observations from the Chandra High Energy Transmission Grating Spectrometer. These observations sample two new orbital/precessional phase combinations. In the observation near orbital phase zero, the H- and He-like Fe lines from both receding and approaching jets are comparably strong and unocculted while the He-like Si line of the receding jet is significantly weaker than that of the approaching jet. This condition may imply that the cooler parts of the receding jet are eclipsed by the companion. The X-ray spectrum from this observation has broader emission lines than obtained in Paper I that may arise from the divergence of a conical outflow or from Doppler shift variations during the observation. Using recent optical results, along with the length of the unobscured portion of the receding jet assuming adiabatic cooling, we calculate the radius of the companion to be 9.6 ± 1.0 R ☉ , about one-third of the Roche lobe radius. For a main-sequence star, this corresponds to a companion mass of 35 ± 7 M ☉ , giving a primary source mass of 20 ± 5 M ☉ . If our model is correct, this calculation indicates that the compact object is a black hole, and accretion occurs through a wind process. In a subsequent paper, we will examine the validity of the adiabatic cooling model of the jets and test the mode of line broadening.