May GWs signals by BH BH merging be associated with any gamma or   neutrino burst? The case of a NS NS merging in GW GRB170817A
  The Gravitational Wave (GW) events GW150914, GW151226, GW170104 detected by LIGO were a record of Black Hole binary merging system (BH-BH) very probably in nearly empty or a vacuum space; such a kind of events will be mostly with no baryon mass (plasma or dense masses) and therefore mute or blind in any correlated gamma band. If the GWs events might be born inside a globular cluster, a star forming region or along a spiral AGN accretion disk their additional accreting mass may be the needed baryon load to explode and shine: in those dense places. BH BH collapse may also offer an optical X and gamma afterglow via their baryon lightening and photon tracks. Only very nearby (tens Mpc) BH Neutron Star (NS) or NS NS cannibal merging might be guaranteed and associated also with a desired, visible and correlated spherical NS explosion (kilonova one); they require much lower threshold or just nearer distances. Indeed such a very exceptional GW170817 GRB170817a event occurred last August 2017; it took place and it was related to a very first NS NS collapse in a SN kilonova spherical explosion. The GRB170817a gamma, X, radio signature it was exceptional in many features . Its unique values (softer, weaker, the most near and long life one) made GRB170817a very possibly an off-axis jet detection. However there are solid arguments that suggest that such a GRB are not just blazing within a collimated beam jet but that they are also shining in a wider spread gamma equatorial disk blazing, orthogonal to the jet itself. In a few words we were observing the event not along its jet but mostly orthogonal to it. This GRB170817a geometry may better explain the otherwise unexpected beamed to us event. In this paper therefore we summarize the astrophysical and the cosmological signature of such a long desired multiple astronomy. 
Daniele Fargion, Pier Giorgio De Sanctis Lucentini, Pietro Oliva,   Maxim Yu. Khlopov
astro-ph.HE