QSO project: Giant Lyman alpha nebula around the hyper-luminous quasar SDSS J1538+0855

The advent of the VLA/MUSE integral field spectrograph recently allowed an efficient discovery of GLAN around bright quasars at z 3-4. So far only 15-20 GLAN have been discovered/studied with MUSE. They exhibit luminosities of 10^43-44 erg/s, sizes of hundreds of kpc and a range of morphologies from symmetric to strongly asymmetric/filamentary. The majority of them do not show a coherent kinematic structure and exhibit narrow line profiles (500-700 km/s). Here we report on a 1h MUSE observation of SDSS J1538+0855 (z 3.6), one of the most luminous broad absorption line quasars in the Universe. We will present its GLAN detection, report on its properties, compare them with nebulae reported in known sources and discuss its link to the central active nucleus.