Solving the missing GRB neutrino and GRB-SN puzzles arXiv:1605.00177v3 [astro-ph.HE] 9 Aug 2016 Daniele Fargion • Pietro Oliva Abstract Every GRB model where the progenitor is assumed to be a highly relativistic hadronic jet whose electronpair secondaries are feeding the jet’s engine, necessarily (except for very fine-tuned cases) leads to a high average neutrino over photon radiant exposure (radiance) ratio well above unity, though the present observed average IceCube neutrino radiance is at most comparable to the gamma in the GRB one. Therefore no hadronic GRB, fireball or hadronic thin precessing jet, escaping exploding star in tunneled beam, can fit the actual observations. A new model is shown here, based on a purely electronic progenitor jet, fed by neutrons stripped from a neutron star (NS) by tidal forces of a black hole or NS companion, it may overcome these limitations. Such thin precessing spinning jets explain unsolved puzzles such as the existence of the X-ray precursor in many GRBs. The present pure electron jet model, disentangling gamma and (absent) neutrinos, explains naturally why there is no gamma GRB correlates with any simultaneous TeV IceCube astrophysical neutrinos. A thin persistent electronic beaming, born in an empty compact binary system has the ability to offer the answer for a sudden engine (the thin jet) whose output may be comparable, off axis, to 1044 –1047 erg s−1 . The jet power is fed by a stripped neutron mass skin by tidal forces. The consequent jet blazing to us on axis occurs within the inner jet cone beammed by a spiral charged ring at highest apparent output. In rare cases, the NS, while being stripped by the BH companion, will suddenly become unstable and it will explode and shine during the GRB afterglow, with an (apparent) late SN-like Daniele Fargion Physics Department, Rome 1 University and INFN Rome1, Ple. A. Moro 2, 00185, Rome, Italy Pietro Oliva Electrical Engineering Department, Niccolò Cusano University, Via Don Carlo Gnocchi 3, 00166 Rome, Italy MIFP, Mediterranean Institute of Fundamental Physics - Via Appia Nuova 31, 00040 Marino (Rome), Italy event birth. Primitive SN outer chemical mass shells, should be retro illuminated by such a NS explosion, re-brightening the relic nuclei as in a SN-like spectral line signature. To disentangle SN from NS explosion we note that only radiative shining due to Cobalt and Nichel decay, present in most SN, will be absent in present NS explosion. Recent IceCube-160731A νµ event with absent X-γ traces confirm the present model. Keywords gamma rays: bursts – stars: binaries – supernovae: general 1 Introduction Gamma ray burst (GRB) physics represents today a halfcentury (1967–2016) unsolved puzzle which brings together a long list of unanswered questions related to the many faces a GRB can show. The main popular fireball model and its modern variations are always doomed to fail in front of a key lethal unanswered question: how we do explain the existence of tiny X-ray precursors (present in hundreds of GRBs) seconds or minutes before the huge apparent gamma explosion? No fireball nor any one-shot fountain model even try to face this reality or seems to be comfortable with the existence of precursors. Maybe the time has come to embrace a change. One of the most important puzzles to recall is: how is it possible that a huge GRB (apparently isotropic) power PGRB ∼ 1053 erg s−1 can sometimes coexist (see i.e., Iwamoto et al. (1998); Melandri et al. (2014)) with a late correlated supernova (SN) event of the typical order of PSN ∼ 1044 erg s−1 , a power billion times weaker? Indeed, this question represents only the tail of a long chain of mysteries surrounding the nature of GRBs. First of all, because of the fast millisecond-second scale of GRB variability, how could any corresponding compact source emit at MeV energies any apparent spherical GRB luminosity 2 Fig. 1 The complete sample of GRBs with known redshift plotted against their relativistic invariant peak power (evaluated in a standard expanding cosmic model, assuming isotropic radiation) shows many orders of magnitude increment with its redshift. The rarest soft GRBs, as the nearest ones, have to be very abundant also at far redshift, but they are hidden by their weak detection threshold; the far away GRB are located in the largest volumes and in richest sample, where the most rarely aligned γ jet might be pointing to us emerging as the brightest and hardest (and often mostly variable) ones; their thinner jet beam whose harder core is narrow because the most energetic UHE electrons showering in gamma shine with brightest luminosity while the wider cone that are fed by lower energetic electron pairs may naturally explain the longer life X afterglows and the apparent anti-copernican evolution around us. Also the hard-luminosity connection found in Amati diagrams has a natural explanation in the beamed relativistic jet cones structure. Let’s also remind, among the puzzles, that UHECR distribution still appears isotropic and uncorrelated with sources, even considering magnetically-induced alignments (see i.e. [Pierre Auger Collaboration et al. (2012)]). PGRB & 1051 ÷ 1053 erg s−1 several orders of magnitude above Eddington limit for such objects (∼ 1038 erg s−1 )? In such a model photon scattering will lead to the birth of electron pairs so dense and opaque that they will definitively screen off and shield the GRB self prompt compact spherical explosion. Moreover no GRB show just a single bang (as in a SN), on the contrary the most of them show a sequence of peaks in gamma. The early (1980–2000) “fireball” model [Cavallo (1978); Goodman (1986); Paczynski (1986); Rees & Mészáros (1992, 1994); Paczynski & Rhoads (1993); Waxman (1997); Sari (1997); Vietri (1997); Cen (1999)] tried to explain that the sea of electron pairs from a GRB will spread out and dilute in a sphere, the so-called fireball, hence cooling the photons in an adiabatic expansion from MeV to keV energies. The model then foresaw that when the pair-sea shell would have become sufficiently diluted and transparent, these keV photons (ejected and scattered by these ultrarelativistic electron pairs) would reach us boosted at MeV energies like the ones observed in GRBs. Since the Beppo-SAX identification and discovery of the high cosmic redshift of some GRBs with extremely high luminosity Piro & BeppoSAX Team (1997); Feroci et al. (1997, 1998) this simple isotropic model depicting “spherical” GRBs failed, mostly because of the observed highest GRB integrated energy (EGRB & 1054 erg) which is comparable or larger than the same source bud- get allowable energy mass, a mass derived and constrained by the object’s Schwarzschild radius (fixed or constrained by its variability). Clearly, such an energy budget paradox could not be solved by an increase of the GRB mass and its Schwarzschild radius because of the subsequent increase of the variability time scale in disagreement with the observed fast ms GRB timescales. Subsequently in 2000, most authors abandoned the spherical fireball model and turned to a mildly beamed jetexplosive fountain model with a ∆Ω/Ω ∼ 10−3 ratio Sari & Piran (1999); Eichler & Levinson (2000); Mészáros (2000) while the inner (random) variability (peaks and sudden re-brightening) of the GRB luminosity was explained assuming that the fountain jet would hit relic shells of matter around (but external) the GRB, where shock waves revived the GRB luminosity. Unluckily for fireball believers, this ad hoc model was and still is not able to explain the multi-peak structure of some GRBs: to face this variability and to keep alive the fireball model several authors considered the far external relic shells of the exploding GRB star as the additional onion-like screens where, by scattering of the expanding shock waves, the explosive luminosity re-brightens several times. Obviously this process, fireball defenders said, must open the fireball fountain jet into an increasingly spread out spherical explosion with a more and more diluted luminosity. Several GRBs on the contrary proved an opposite 3 growing peak luminosity trace. Moreover each onion shell in such models must be diluted enough to transfer outside the GRB shock wave but not too diluted for being transparent to the scattering: such a fine-tuned GRB dressing for fireball is purely ad hoc and unexplained. In particular the fireball one shot model is totally incapable of describing and justifying the early X-ray precursor Fargion (2000, 2001) present in a significant fraction (∼ 7% ÷ 15%) of GRB curves up to date. These earliest bright X-ray flares may hold a million times the SN luminosity even several minutes (ten minutes for GRB 06124) before the main (billion times brighter) harder GRB event. Moreover, the wide beaming of the fountain (∆θ ∼ 10◦ ÷ 15◦ ) is assumed ad hoc and the single-shot model cannot describe some observed long life and “day after” re-brightening GRBs, nor the several week X-ray afterglows. Moreover the fireball model is unable to justify the apparent “conspiracy” that makes GRB more and more (in apparent) brightest power at larger and larger redshift, in a spread of apparent luminosity of nearly a factor a billion discussed below: a beaming factor of just a thousand as in fireball model, cannot explain more than a thousand in luminosity range variability. On the contrary a thinner precessing jet whose solid angle is a million or billion times smaller, may embrace a million or a billion luminosity variability. The same plot play a role in making (apparent) harder and harder the GRB spectra with the more and more distance (and red-shift). Naturally, we are observing a statistical geometry evolution that allows the most distant and richest sample to have the most aligned and thinner jets pointing towards us, while the nearer (smaller cosmic volume) and rarer GRB are usually off-axis and they shine with low fluxes. solid angle and the apparent luminosity grows as large as the square of the Lorentz factor (of highest energetic electrons). Of course also a hierarchic cannibal event between binary compact objects may play a role, showing new rare powerful jet with wider distances and volumes. However as it is well known binary (Schwarzschild or Kerr neutral) BH merging systems are ejecting only gravitational waves (GW). Therefore only (or mainly) neutron star merging, as discussed below, in BH-NS or in NS-NS systems are a guaranteed source of electromagnetic radiation and the NS are a well-bounded amount of mass-energy. Therefore even if the GRB event is fed by NS-NS or NS-BH binary merging, even for large and large BH, the outgoing energy budget in GRB is nearly fixed and bounded by the NS mass. The huge luminosity variability is due to the very thin beaming geometry associated to tens-hundred GeV electron pair jets, not to any hierarchic growth of objects. 2 An anti-Copernican GRB Luminosity evolution? Among the contradictions of all GRB one-shot models stand the apparent conspiracy of GRB luminosity around us: nearby (lowest red-shift) GRBs show on average a peak luminosity and a soft energy spectra versus the much brighter and harder luminosity of far away (large redshift) GRB events. The conjure or the apparent luminosity evolution is so fast that it suggest that we (in our local Universe) are at the center of the Universe. There is not any ad hoc luminosity evolution that may explain such a sudden (z & 0.01) growth in spectra and luminosity evolution. This result is manifest in Fig. 1, and it calls for an explanation. A wide fountain and a marginal beaming as in a fireball model cannot explain such a factor of a billion in luminosity spread; a very thin beaming (as will be discussed below within a millionth or less of steradian solid angle) spinning and precessing jet has a characteristic angle linked to the peak electron Lorentz factor above thousands value: the inverse of the Fig. 2 top: Neutron star (NS) orbiting in an elliptical eccentric trajectory, skimming a black hole (BH) companion object; bottom: NS suffering a tidal force able to strip neutron dense matter along an accretion disk. The neutron in free fall start to decay leading to a nearly (unmoved) proton tails, a free spherical evaporating ∼ MeV beta decay ν̄e and an almost similar cloud of ∼ MeV electrons. 3 Precessing and spinning of thin decaying γ jet In order to overcome the GRBs puzzles we proposed since 1994 Fargion (1994, 1995) a model to describe both GRBs (and/or SGRs) based on the blazing of a very thin γ beamed jet (∆θ ∼ 0.1◦ ÷ 0.02◦), ∆Ω/Ω . 10−6 ÷ 10−8 whose 4 electrons trapped in the poles into an ultra-relativistic jet which will later create the observable gamma jet. This novel electronic model is able to avoid the pion progenitor and the overcrowded neutrino tails foreseen in all hadronic GRB models explaining GRB-ν absence. 3.1 GRB with SN event Fig. 3 Protons follow their ring trajectory while in β-decay forming a net charged current and a huge aligned magnetic field B p . The evaporating electrons are easily captured and aligned along B p ; their crowding at the North and the South Poles create a huge electrostatic gradient that makes a powerful linear active accelerator: an electronic jet arises and ejects electrons and/or electron pairs by bremsstrahlung as well as photons (by inverse Compton scattering and synchrotron radiation); the thin spinning and (by tidal gravity forces) precessing jet, drives a collinear γ jet making a blazing dance by its geometry beaming Fargion & Grossi (2006); Fargion (2006). Once on axis, we are dazzled and we call it a GRB event. birth was associated to tens GeV electron pairs showering via inverse Compton scattering (ICE) into MeV-GeV photons Fargion et al. (1997); Fargion & Salis (1998). Our precessing-spinning γ jet was assumed fed at a low power (fitting today SGR or AX-PSRs) in our galaxy (PSGR ∼ 1038 erg s−1 ) or, since 1998 Fargion (1999), also at highest power as large as a SN powering and beamed jet for cosmic GRBs (PGRB ∼ γe2 PSN ≃ 1050 ÷ 1054 erg s−1 ). Late GRB jet power, decaying with a power law ≈ t−1 , may shine as an nearby exhausted soft gamma repeater (SGR) jet source where the output power is correlated with a thousand year time delay with the early GRB and present SGR output. The geometrical spinning and precessing of the thin GRB-SGR jet naturally explain the huge GRB variability and the quasi-periodic behaviors found in well recorded SGR events. In the present model discussed below, the feeding of stripped matter of a NS by a black hole (BH) or a NS companion, is shining energy: indeed stripped neutrons and protons condense into a charged spiral ring that is paying the energetic output budget to eject a thin collimated, spinning and precessing electron jet, at 1044 − 1047 erg s−1 output; moreover the bending geometry of the electron jet (by bending magnetic fields of the accreting ring and the BH spin) and its consequent beamed variability, explain the huge and fast GRB-SGR luminosity. The fact that the neutron by NS star stripped matter and its decayed protons will follow the spiral geodesic around the BH or NS cannibal companion (while the electrons and neutrinos will not) will lead to a charged ring and a sudden collimating magnetic field. This decaying neutron-e+e− pairs-proton ring, which is also pulsating, can shrink the magnetic lines and it can force the In some occasion such an electronic jet model formed around the BH, or heaviest NS companion, may also lead to an explosion of the relic stripped NS binary, which is now unstable because of the spoiled and stolen external weights. Because of the extremely beamed angle (∆Ω/Ω ∼ 10−6 ÷ −8 10 ) these apparent luminosity, if seen in-axis by the observer, would shine apparently as bright as a P̃SGR ∼ 1044 ÷ 1046 erg s−1 while P̃GRB ∼ 1050 ÷ 1054 erg s−1 . The lifetime of the jet has been assumed not to be a one-shot event (as the fireball model does). On the contrary our thin precessing and spinning jet has a characteristic decay life about GRB tdecay ≃ (t/t0 )−1 , where t0 ≃ 3 × 104 s. This half-aday timescale was chosen to connect, by a time decay law P ∼ (t/t0 )−1 the highest GRB output to late, thousand years later, less powerful relic, almost steady (Galactic as SS433) Soft Gamma Repeaters, SGRs. Despite being able to explain even the X-ray precursor (by a peripherals skimming shine of the jet to the Earth, before the main jet blazes as a GRB) and the late GRB rebrightening through simple geometry beaming, the precessing jet model unifying GRB and SGRs was (and it is) often underestimated or un-noticed Fargion (1999) since twenty years. 3.2 Hadronic jet feeding a fireball lepton–γ jet The fountain-fireball model was — and is — based on shock interacting shells of hadrons (UHECR at PeVs÷EeV, protons and nuclei) leading to neutral pions (π0 → 2γ) as well as to charged ones (π± ) whose final decay results in electron pairs, the ones that later will shine in γ in the GRB and a rich tail of neutrinos (νe , νµ , ν̄e , ν̄µ ) as well. There is also the possibility to feed pions by UHE nucleons and nuclei interacting with photons in flight. Also more violent charmed hadronic reactions lead to prompt secondaries as the ones above. In this context the most popular fireball model foresees a comparable trace of γ luminosity under the form of GRBs with respect to a neutrino radiance, as they were just secondaries of charged pions in decay in vacuum space. Nevertheless, we repeat, GRB occur in dense stella shells in fireball model. Naturally, because of the photonphoton interaction and/or IR-tens TeV opacity most of highest TeVs photons degrade and decay into MeV÷GeV ones (directly at their source or along their cosmic flight). This is not the case for tens TeVs or PeVs complementary neutrinos that may reach us unabsorbed showing (in this popular 5 and ideal fountain-fireball model) the same radiance imprint of the partially absorbed gamma observed in GRBs. As we shall comment, the transparent pion decay in flight, in fireballs, is a wishful chain of events, mostly very unrealistic because most of the onion shell barrier encountered by the fireball jet will be (mainly at the inner core) opaque to photons but not to neutrinos. Photons will fed the kinetic energy of the barrier shells while UHE neutrinos will escape with nearly no losses. If the inner star core shells are opaque even to the neutrinos then only the rare interacting UHE neutrinos, making UHE penetrating muons at the external edges, may feed the GRB with electromagnetic secondaries, while most of the primary neutrinos will export to us much more energy than gamma in GRB anyway. In conclusion the ratio gamma - neutrinos comparable to the unity is a “chimera”. The so-called Waxman-Bahcall (WB) limit or bound Waxman & Bahcall (1999), which connects ten EeV cosmic ray (CR) radiance (ΦCR ∼10 eV cm−2 s−1 sr−1 ) with average cosmic GRBs one (ΦGRB ∼ ΦCR ), constrains the expected cosmic tens TeV÷PeV GRB neutrinos (GRBνs) at similar GRB energy radiance. Indeed, the expected WB neutrino signal didn’t arise with any correlated GRB yet, or it might be rarely (∼ 1%) arose as a possible precursor. The absence of any prompt GRB–ν correlation represents a remarkable failure of any one-shot fireball version, even the most beamed one. No room for one-shoot GRB neutrino and gamma event Fargion (2014). Furthermore, any hypothetical dark or hidden population of GRB should not be considered, for this would call for a higher and higher ratio (ΦνGRB /ΦγGRB ≫ 1) while the observaγ tions are telling us (ΦνGRB /ΦGRB ∼ 1) Abbasi et al. (2012); IceCube Collaboration et al. (2016). In our thinner precessing jet we might solve the huge apparent GRB power spread puzzle in a first approach because of the ultra-relativistic beaming and the consequent thin beaming angle: the higher the energy, the thinner the jet cone and thus the rarer the blazing, which of course explains why we have observed (at tens to hundred keV) thousands of GRBs, a few hundred GRBs at a MeV to tens MeV, a few dozen at a hundred MeV to GeV energies and only few rare events at a hundred GeV, the beming explaining their rarety. The precessing jet model can also shine in an almost cyclic fashion (like SGRs) and might blaze partially as a rare precursor, ruling out the mysterious 10%÷20% GRB events with precursors. In principle a thin relativistic beaming may explain that TeV neutrinos are so beamed that their shining inside the wider X-γ cones happens very rarely. Furthermore, this requires a prompt ν detection with a fast follow up in X-γ range. The first attempts (see next section), have failed. daries whose decay in flight were able to escape and survive the eventual opaque stellar mass layer and photosphere of a SN explosion Fargion & Grossi (2005). In addition, the same µ+ µ− shined in ν, ν̄ at higher and higher than unity ratio respect to photons; this applies for the following reasons: if GRB’s γ are made by relativistic electrons radiation and if the GRB jet are originated by UHECR hadrons inside the collapsing star, than only a small fraction of the UHECR energy radiance is able to escape the matter barrier in the form of secondary final γ constituting the GRB. Most of the hadron jet energy is dispersed and wasted inside the baryonic shell kinetic energy and its temperature along the jet shock wave propagation. The basic huge absorption of any electromagnetic traces respect to neutrino ones is a severe argument against any hadronic GRB origination. Present low (or missing) neutrino records in IceCube with respect to same observed gamma radiance in nearly a thousand GRB probe it Aartsen et al. (2016). 3.3 An hadronic or electronic precessing jet? 3.4 The absence of γ-X signal from IceCube-160731A We admit that our precessing γ jet was originally based on hadronic-UHECR primaries, leading to PeVs µ+ µ− secon- The very recent prompt search of an electromagnetic trace by an astrophysical candidate event IceCube-160731A have Fig. 4 top: while in spiral trajectory the NS is sometimes too much bent and tidally disturbed by the BH up to lose an important fraction of its mass in the ring. It may also be a more quite serene and steady NS strip to lighter and lighter relic mass (it may be also that the final NS is eaten in a prompt step by the BH); bottom: anyway the survived NS fragment may become unstable (mostly below a minimal NS mass mNSmin . 0.2 M⊙ ). 6 To be more quantitative let’s recall the ratio between ν and the electromagnetic tail of atmospheric CR both on the ground and in deep kilometer-underground detectors as well as across the Earth (for neutrino event rates in different scenarios see i.e. Fargion et al. (2012)). Atmospheric muons or e± , µ± from νµ,e , ν̄µ,e are the observable electromagnetic traces in the last case: ΦCR /Φν ≃ ΦCR /Φµ+ µ− & 102 on the ground; ΦCR /Φµ+ µ− & 108 in underground detectors; ΦCR /Φµ+ µ− & 1014 in case of up-going signals Fargion (2002); Fargion et al. (2004). The corresponding shields are namely 10 m w.e., 2 km w.e. and 105 km w.e. In general the ratio between ΦCR /Φγ is related to the ratio between the baryon barrier size Db , the propagating lepton µ+ µ− distance lµ and the interacting and propagating νµ , ν̄µ → µ+ , µ− . In summary, the ratio ΦCR /Φµ+ µ− is related to the surviving Fig. 5 Unstable NS suddenly evaporate its surface by free neutron β-decay toward a catastrophic NS explosion similar or even more muons and the propagating distance: ΦCR /Φµ+ µ− ≃ e−Db /lµ energetic that a SN one. and for largest baryon barrier (Db ≫ 12 km) the muons arise by the appearance of high energy atmospheric neutrinos interacting with matter. proven the embarrassing absence of any optical (H.E.S.S.), The lowest ratio (in first approximation) between a surX-γ (Swift, Fermi, Agile) correlated signal (see Astro-Telegram vived neutrino over a gamma average GRB radiance (as(2016)). A first and rough estimate of downgoing energetic suming a dozen km size rock shell along the hadronic jet νµ neutrino at ∼ 100 TeV in a km3 IceCube has a pure probtrajectory) maybe estimated assuming (as for IceCube) a ability to interact (∼ 10−4 ). therefore, the consequent exprimary prompt 30 TeV neutrinos whose most penetrating pected IceCube-160731A released energy is ∼ 1018 eV over secondaries (the muons) escape as well after tens km rock a km2 area, or 108 eV/cm2 energy fluence. On the contrary they are shining outside the shell as muon first and later on the electromagnetic bounds in Swift (as well as in Fermi 2 as electron pairs and gamma: Φν /Φµ+ µ− ≃ lν /lµ , above ten and other detectors) are as low as 1 eV/cm energy fluence. thousand. In conclusion the minimal ratio of neutrino over The main consequence is that even no a part of a million gamma radiance should be around ten thousand and not one, is related in γ respect to ν signal. Therefore, there are no if GRB are hadronic in primary nature. hadronic jets in GRBs (or worse no clear understanding of IceCube astropysical ν nature, Fargion et al. (2015)). 3.6 Where is the gamma radiance lost? 3.5 Cosmic rays and hadronic jet surviving analogy If in the hadronic GRB jet, a large fraction of the gamma To depict the analogy in a more clear way let’s recall the output is lost in opaque shells, one may wonder that this is CR metamorphosis along their flight inside the Earth atmoimpossible because the energy conservation is lost. Indeed sphere, which is a ten meters water equivalent (w.e.) screen: in the sun the radiation is both in photons and in neutrinos. at ground level only a small amount of the CR energy is obWhy should it not be the same in GRBs? The reason is that servable under the form of electromagnetic secondaries (e± , the solar photons are in late thermal equilibrium stage while γ). Most of the surviving electromagnetic traces are indeed GRB photons are out of equilibrium. Therefore where did µ+ µ− , whose energy radiance is already suppressed by two the gamma energy fade (with respect to the neutrino one)? orders of magnitude with respect to the primary GeV p (nuWe believe that in any hadronic GRB (outside of a fineclei) at the top of the atmosphere. Most of the relic energy tuned case where the external shell are just transparent ad is lost as heat and as kinetic energy spread by CR showering hoc) a large part of the gamma energy should be absorbed in air. A large fraction of the surviving CR trace is repreby the baryon matter while being scattered and-or being absented by the atmospheric neutrinos at a hundred MeV that sorbed, accelerating the shell masses in the form of kinetic exceed by 3÷4 orders of magnitude the corresponding MeV shells. The explosive kinetic shell masses as well as part γ component arriving at sea level, although in very speof the survived cosmic rays (escaped along the jet) might cial fine-tuned cases of EeV airshowers we can find a great contain the primary hadron and gamma energy, while the electromagnetic component comparable to the ν one on the neutrino component (born at the same inner sources) will ground. In general the surviving atmospheric neutrino secsuffer a negligible depletion, surviving with higher energy ondary tail exceeds by many orders of magnitude the correfluency. In conclusion, once again, neutrino radiance should sponding electromagnetic component (mainly muons) while be much larger than gamma one in the most general hadronic crossing the hadron barrier along the jet propagation. 7 jet model crossing star shells. However, the data show a comparable or a minor neutrino radiance with respect to the gamma ones. This is the main need for a pure electronic jet in GRBs. 4 Binary BH-NS feeding accretion disk and powering γ jet In the light of this absence of GRB-ν (3.4), we are forced to consider a new engine process able to avoid any pion decay chain. The most natural one is a binary system in empty space made by a neutron star (NS) and a black hole (BH) in an elliptical trajectory with each other. At a nearby encounter, as depicted in Fig. 2, the NS may suddenly lose a fragment of its mass because of tidal forces at relativistic Roche limit Fishbone (1973). These neutrons are led within tens of minutes toward the last extended boundary (r ∼ 3RSchwarzschild ) of the BH while the decay n → p+e− + ν̄e takes place. The electrons will then escape at low MeV energy, leading to a poor spherical (hard to detect) signal, while the protons which don’t gain too much energy, nor relevant momentum in the decay, will proceed in its geodetic spiraling in a disk-ring around the BH; the ring will be therefore a positive charged ring. The almost relativistic electrons in the meantime will spread themselves in a nearly spherical fashion. The neutron-proton coherent spiraling around the BH will then define a net positive charged current in a ring that is not compensated by a relativistic electronic component of the decay. This induces a huge axial magnetic field B p proton-induced which is represented in Fig. 3; the magnetic lines force the electrons to concentrate themselves toward the BH accretion disk’s poles (let’s call them north and south according to the magnetic field polarity). The electrons will then be forced and squeezed by a powerful charged pump that accelerate the e− in a jet at highest energies well above the starting MeV ones. Within such a dense relativistic electron beam flow, because of selfelectron Compton scattering, inverse Compton and pair production, collinear pairs e+ e− and γ will arise resulting in a final γ jet. The BH spin and the ring spin will interact and precess among themselves. In the proton disk, meanwhile, for the accumulated charged asymmetry, some of the external circuiting protons will start to escape at equatorial disk edges (see Fig. 3). Clearly, the extreme collimation of the pairs e+ e− and γ avoids the Eddington opacity that normally occurs for spherical luminosity and the huge dense NS mass feeding the proton ring represents a very powerful engine (ṁNS ≃ 10−6 ÷ 10−5 M⊙ s−1 ). This mass loss, then, powers the BH accretion disk and the jet, whose blazing toward the Earth is perceived as a GRB. After a few days or months the NS is doomed; its strip for the benefit of the BH ring may lead to Fig. 6 Unstable NS explodes in a spherical SN-like event, observable days or weeks after first GRB blaze. Shells of energy of the supernova embrace the same BH jet. The asymmetric binary BH is suddenly without a companion and it is launched tangentially with a high speed kick (see Bogomazov et al. (2007)) in a fast flight holding alive its ring and its jet. The latest stages of the BH fed jet may shine as a SGR. The model NS-BH maybe dressed in a similar NS-NS evolution where the final relic is a spinning NS jet; this version may fit the SGRs or AX PSRs relics observed in our own galaxy. instabilities (see Fig. 3.2) and the reason for that is simple: a very minimal NS mass (mNS min . 0.2 M⊙ ) may become too light to hold together nuclei (see Sumiyoshi et al. (1998)) and its surface gravity weight becomes unable to compensate the nuclear chemical repulsion potential (as happens in a normal NS). Neutrons from the surface would then start to decay and escape making the degenerate system totally unstable in a matter of tens of seconds or few minutes (Fig. 3.2). This would lead to a sudden spherical explosion appearing from Earth as a SN event (Fig. 3.3). However, it is not trivial to tell if the critical minimal neutron star mass could release much more or much less energy than of a canonical SN. The energy potential budget for a NS collapsing in a normal SN accounts for around 10% of the object rest mass (∼ M⊙ ). Therefore, an apparent SN-like event like the one celebrated SN-GRB related to GRB 980425 may be attributed to such a simple process of a minimal NS explosion without any correlated beamed neutrino and with a few days (or a week, Maeda et al. (2007)) delay with respect to the main GRB blaze. Naturally, the shining of the spherical NS explosion may heat and excite the external surrounding (original SN shell from where NS itself or BH is formed) shell leading to spectroscopic emission and absorption lines that may mimic the SN explosion. On the contrary, the Ni and/or the Co radioactive decay mode are not naturally born (therefore there might be a remarkable imprint to be discussed elsewhere that might distinguish the SN from the NS-like explosions). We like to stress that this electromagnetic pump accelerator mechanism does not require any hadron parental engine, 8 any consequent muons or energetic neutrinos, explaining the the observed absence of ICECUBE neutrino radiance (larger than the photon one) and-or the missing GRB-ν correlation. 4.1 Bimodal Short and long GRB There are also natural corollary consequences of the proposed model: we can find a similar tale for a NS-SN binary collapse where one of the two NS “eats” and “strips” matter from the companion NS leading to a similar story-board. Because such a NS-NS binary systems are among the narrow ones then we imagine that also their characteristic blazing times are sharper leading to more short duration GRBs. Therefore these shorter GRBs may populate the short events, whose duration is below 2 s. Larger sized BH-NS binaries, like the very recent candidate in the LIGO-VIRGO gravitational wave detection Abbott et al. (2016), system may imply a wider family of NS-BH with BH masses as large as 10 ÷ 100 ÷ 1000 M⊙. These are possibly the longer duration GRBs whose characteristic time is longer than 2 s. The infrequent and sporadic presence of largest BH makes rarer and rarer the longest GRB events explaining the rarest long life GRB , thousand second long. Also late GRBs whose early explosion has not been in axis but whose late precessing jet is pointing (as a young SGRs) to us at a still high output, may appear as a short GRBs mostly at nearer cosmic distances (respect peaked GRB luminosity). 5 Conclusions If the SGRB and LGRB are explained by NS-NS (SGRB) and NS-BH (LGRB) models, then the main puzzle of the apparent over-Eddington luminosity is simply solved by high collimated beaming. The tidal ring-jet perturbation and the spinning of the BH versus the disk makes the jet spin and precessing as well as blaze in the observed almost chaotic way (see Fig. 4). The absence of longest events, almost comparable with largest optically violent variable quasar 3C 279 gamma flare is simply related with the rarity of supermassive BH (as the AGNs) respect lighter tens-of-hundreds or thousands solar masses. The coexistence of a SN-like event (for a quick review see i.e. Woosley & Bloom (2006); Bersier (2012)) is solved by light tidal NS sudden evaporation and consequent explosion. The absence of TeV neutrinos correlated with GRBs is guaranteed by the absence of any hadronic accelerator as well as leptonic neutrino tails in GRB. The thinner precessing jet moreover still explains the statistics we see, i.e. in Fig. 1. The model consistence is based on the geometrical evolution of a thin persistent jet whose acceptance today, after twenty years, is becoming more and more obvious. We admit that for a long time we also assumed that such thin jets were powered by hadronic engine (muons) Fargion (1999); Fargion & Grossi (2005); Fargion et al. 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