High Density Reflection in the X-ray binary GX 339-4
Abstract
A weak low-temperature thermal component is commonly seen in the X-ray spectra of stellar-mass black holes (BHs) in the hard state. Another common result obtained in previous reflection-based spectral analysis is a supersolar iron abundance, while all the other elements are assumed to be solar. A disk reflection model with a higher disk density might be the solution to both problems. We present a broad band spectral analysis of the BH binary GX 339-4 with NuSTAR and Swift using high density reflection model. The high density reflection model can explain its hard state spectra with no requirement for an additional low-temperature thermal component. For the first time, this model enables us to compare the density in the disc surface of GX 339-4 in different states. The disc density in the hard state is log(ne)≈21, 100 times higher than the density in the soft state (log(ne)≈19). A close-to-solar iron abundance is obtained by modelling the broad band spectra.
- Publication:
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AAS/High Energy Astrophysics Division
- Pub Date:
- March 2019
- Bibcode:
- 2019HEAD...1711226J