2008/02/29 by J. M. Mïller, J. M. Miller, C. S. Reynolds +10 · 7 citations
Physics and Astronomy · #Accretion (finance) #Accretion disc #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Black hole (networking) #Emission spectrum #Intermediate-mass black hole #Line (geometry) #Physics #Reflection (computer programming) #Rotating black hole #Spectral line #Spectroscopy #Spin (aerodynamics) #Spin-flip #astro-ph
paper · pdf · doi:10.1086/589446
4 pages, 3 color figures, accepted for publication in ApJL 4/16/08
arxiv created 2008/04/17 · openalex publication_date 2008/05/06 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report on a deep Suzaku observation of the stellar-mass black hole GX 339–4 in outburst. A clear, strong, relativistically shaped iron emission line from the inner accretion disk is observed. The broadband disk reflection spectrum revealed is one of the most sensitive yet obtained from an accreting black hole. We fit the Suzaku spectra with a physically motivated disk reflection model, blurred by a new relativistic line function in which the black hole spin parameter is a variable. This procedure yielded a black hole spin parameter of a = 0.89 ± 0.04. Joint modeling of these Suzaku spectra and prior XMM-Newton spectra obtained in two different outburst phases yields a spin parameter of a = 0.93 ± 0.01. The degree of consistency between these results suggests that disk reflection models allow for spin measurements that are not strongly biased by scattering effects. We suggest that the best value of the black hole spin parameter is a = 0.93 ± 0.01 (statistical) ± 0.04 (systematic) . Although preliminary, these results represent the first direct measurement of nonzero spin in a stellar-mass black hole using relativistic line modeling.