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Volume 306 - XII Multifrequency Behaviour of High Energy Cosmic Sources Workshop (MULTIF2017) - Gravitational Waves
May GWs signals by BH-BH merging be associated with any $\gamma$ or $\nu$ burst? The case of a $NS − NS$ merging in GW-GRB170817A
D. Fargion,* P.G. De Sanctis Lucentini, P. Oliva, M.Y. Khlopov
*corresponding author
Full text: pdf
Pre-published on: 2018 April 12
Published on: 2018 May 30
Abstract
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. By best GW triangulation (as soon as Virgo has been active) their position will be widely located only in a smeared sky (tens or hundred square degree) because of the absence of any correlated spherically-symmetric electromagnetic signal whose photons might be pointing to the exact sources in the sky. 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-g afterglow via their baryon lightening and photon tracks. However these peculiar orbiting or multi-body systems should also imprint their presence in the inner Kepler period as well as in a perturbed GW signature by unusual time structure. Moreover any Black Hole active (by a relic jets and-or an accretion disk) might shine and blaze during the collapse with a BH by its jet too: however these beams, being extremely collimated, are rarely pointing toward us during the same brief GWs emission. Only very nearby (tens Mpc) BH-Neutron Star (NS) or NS????NS cannibal merging might be associated with a desired, visible and correlated spherical NS explosion (kilonova one); these rare explosion and their GWs might therefore be localized by photon tracks. But they are lower mass system and they require much lower threshold or just nearer distances. Because of such nearer cosmic volumes (tens Mpc) and because of the very anisotropic beamed GRB associated, these kilohertz event are possibly still very rare and unexpected in gamma sky (even with LIGO Virgo array sky narrow view). However the very exceptional GW170817 GRB170817a event last August 2017 it took place and it was related to a very first NS????NS collapse in a SN-kilonova spherical explosion. This event had been recorded both by its few (day and months) optical transient but as well as by its weak, prompt, short, GRB, two seconds later the same LIGO-Virgo detection. The GRB170817a gamma, X, radio signature it was exceptional in many features and one may wonder and he may ask if it was really correlated to the GWs. Its unique values (softer, weaker, the most near 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.
DOI: https://doi.org/10.22323/1.306.0009
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