2014/07/03 by Paul B. Hemphill, Richard E. Rothschild, R. E. Rothschild +8 · 5 citations
Earth and Planetary Sciences · Physics and Astronomy · #Accretion (finance) #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Context (archaeology) #Cyclotron #Cyclotron resonance #Galaxy #High-pressure geophysics and materials #Laser-Plasma Interactions and Diagnostics #Line (geometry) #Luminosity #Nuclear physics #Optics #Physics #Plasma #Scattering #Spectral line #astro-ph.HE
paper · pdf · doi:10.1088/0004-637x/792/1/14
15 pages, 8 figures. Accepted to ApJ on 2 July 2014
arxiv created 2014/07/03 · openalex publication_date 2014/08/08 · arxiv updated 2015/06/22 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present results from the first Suzaku observation of the high-mass X-ray binary 4U 1538−522. The broadband spectral coverage of Suzaku allows for a detailed spectral analysis, characterizing the cyclotron resonance scattering feature at 23.0 ± 0.4 keV and the iron Kα line at 6.426 ± 0.008 keV, as well as placing limits on the strengths of the iron Kβ line and the iron K edge. We track the evolution of the spectral parameters both in time and in luminosity, notably finding a significant positive correlation between cyclotron line energy and luminosity. A dip and spike in the light curve is shown to be associated with an order-of-magnitude increase in column density along the line of sight, as well as significant variation in the underlying continuum, implying the accretion of a overdense region of a clumpy stellar wind. We also present a phase-resolved analysis, with most spectral parameters of interest showing significant variation with phase. Notably, both the cyclotron line energy and the iron Kα line intensity vary significantly with phase, with the iron line intensity significantly out of phase with the pulse profile. We discuss the implications of these findings in the context of recent work in the areas of accretion column physics and cyclotron resonance scattering feature formation.