演講資訊

摘要：

Stellar-mass back hole candidates in X-ray binaries are too heavy to be neutron stars, while supermassive black hole candidates in galactic nuclei are too heavy, compact, and old to be clusters of neutron stars. On this basis, both object classes are thought to be the Kerr black hole of general relativity, but a direct observational confirmation is still lacking. In this talk, I will discuss how the study of the properties of the electromagnetic radiation emitted by the gas in the accretion disk can test the Kerr nature of black hole candidates. In particular, I will talk about the study of the thermal spectrum of thin disks and the analysis of the iron K-alpha line. Both the techniques can already be used to provide some constraints on possible deviations from the Kerr solution, but more interesting tests require new X-ray facilities with larger effective areas.