Testing slim-disk models on the thermal spectra of LMC X-3

Understand

Slim-disk models describe accretion flows at high luminosities, while reducing to the standard thin disk form in the low luminosity limit.

• We have developed a new spectral model, slimbb, within the framework of XSPEC, which describes fully relativistic slim-disk accretion and includes photon ray-tracing that starts from the disk photosphere, rather than the equatorial plane.
• We demonstrate the features of this model by applying it to RXTE spectra of the persistent black-hole X-ray binary LMC X-3.
• LMC X-3 has the virtues of exhibiting large intensity variations while maintaining itself in soft spectral states which are well described using accretion-disk models, making it an ideal candidate to test the aptness of slimbb.