Vol. 577
In section 1. Letters

Proving strong magnetic fields near to the central black hole in the quasar PG0043+039 via cyclotron lines

by W. Kollatschny, N. Schartel, M. Zetzl, et al., A&A 577, L1


The optically bright quasar PG0043+039 has not been detected yet in X-ray, and it has the most extreme ratio of optical to X-ray luminosity in the sky. The authors present X, UV, and optical simultaneous observations, and have succeeded for the first time to detect X-rays from the quasar, confirming its exceptional nature. In addition to usual emission lines,the UV spectrum reveal peculiar broad humps, which can be interpreted as the harmonics of a cyclotron frequency, which are divided into two systems. This allows a plasma temperature of T ~ 3keV to be derived, along with a magnetic field strength of B ~ 2 x 10^8 G for the line-emitting regions close to the black hole.