Combining timing characteristics with physical broad-band spectral modelling of black hole X-ray binary GX 339-4
Journal article, 2019

GX 339-4 is a black hole X-ray binary that is a key focus of accretion studies, since it goes into outburst roughly every 2-3 yr. Tracking of its radio, infrared (IR), and X-ray flux during multiple outbursts reveals tight broad-band correlations. The radio emission originates in a compact, self-absorbed jet; however, the origin of the X-ray emission is still debated: jet base or corona? We fit 20 quasi-simultaneous radio, IR, optical, and X-ray observations of GX 339-4 covering three separate outbursts in 2005, 2007, 2010-2011, with a composite corona+jet model, where inverse Compton emission from both regions contributes to the X-ray emission. Using a recently proposed identifier of the X-ray variability properties known as power-spectral hue, we attempt to explain both the spectral and evolving timing characteristics, with the model. We find the X-ray spectra are best fit by inverse Compton scattering in a dominant hot corona (kT(e) similar to hundreds of keV). However, radio and IR-optical constraints imply a non-negligible contribution from inverse Compton scattering off hotter electrons (kT(e) >= 511 keV) in the base of the jets, ranging from a few up to similar to 50 per cent of the integrated 3-100 keV flux. We also find that the physical properties of the jet show interesting correlations with the shape of the broad-band X-ray variability of the source, posing intriguing suggestions for the connection between the jet and corona.

black hole physics

X-rays: binaries

galaxies: jets

accretion, accretion discs

relativistic processes


R. M. T. Connors

University of Amsterdam

California Institute of Technology (Caltech)

D. van Eijnatten

University of Amsterdam

S. Markoff

University of Amsterdam

Chiara Ceccobello

University of Amsterdam

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Galactic Astrophysics

V. Grinberg

University of Tübingen

L. Heil

University of Amsterdam

D. Kantzas

University of Amsterdam

M. Lucchini

University of Amsterdam

P. Crumley

University of Amsterdam

Princeton University

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 485 3 3696-3714

Subject Categories

Astronomy, Astrophysics and Cosmology



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