Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1603.09639

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

Daniele Fargion·Pier Giorgio De Sanctis Lucentini·Pietro Oliva·Maxim Yu. Khlopov
View original source ↗Read source document ↗Export metadata ↓

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. 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.

Explore related subjects

astro-ph.HE

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Daniele Fargion, Pier Giorgio De Sanctis Lucentini, Pietro Oliva, Maxim Yu. Khlopov. 2018-04-12. 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. https://arxiv.org/abs/1603.09639

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

EP250302a: violent shell collision in a soft-X-ray-selected GRB-like transient

The Einstein Probe opens a previously unexplored soft X-ray window onto gamma-ray bursts, filling a critical observational gap in the soft X-ray coverage of their prompt emission. In this letter, we present EP250302a, a soft-X-ray-selected, GRB-like transient at $z=1.131$ detected by the Einstein Probe. Follow-up observations from X-ray to radio reveal a narrow X-ray flare at $\sim 1.1$\, ks and subsequent achromatic optical and X-ray rebrightening. These features challenge a standard single-component afterglow model and indicate the need for multiple ejecta components. A violent collision between a late relativistic shell and the decelerated leading blast wave provides a plausible interpretation: the flare arises from internal dissipation of the late ejecta, while the rebrightening is powered by the shocked emission produced in the collision. Quantitative modeling constrains the kinetic energy ratio between the late shell and the initial ejecta to $E_{\rm k,iso,2}/E_{\rm k,iso,1} \sim 5$ (with $E_{\rm k,iso,2} \sim 10^{53}$~erg and $E_{\rm k,iso,1} \sim 2\times10^{52}$~erg), as well as the Lorentz factor contrast to $Γ_{2,0}/Γ_{1,0} \approx 0.98$--$2.27$, required to reproduce the observed flare luminosity and rebrightening amplitude. Such an energetic late shell can be launched in a radiatively inefficient second episode of central-engine activity. Thanks to the well-sampled, early-time multiband coverage facilitated by the EP trigger, EP250302a provides a valuable case to test the physical connection between central-engine activity and shell collisions.

astro-ph.HE↗
arXiv2026

$E_{\rm peak}$-$α$ Correlation in Time Resolved GRB Spectra: A Bottom-Up Approach with Optically Thin Inverse Compton Scattering Model

Gamma-ray bursts (GRBs) are the brightest explosions in the Universe, yet the origin of their emission remains uncertain. Time-resolved spectral analysis offers key insights into the evolution of spectral shapes, constraining both radiation mechanisms and emission-site microphysics. Observationally, GRB spectra are well described by the empirical Band function, characterized by the peak energy ($E_{\mathrm{peak}}$) and low-energy spectral index ($α$). We investigate the temporal evolution of spectra produced by optically thin inverse-Compton scattering (ICS) within a standard fireball jet framework, focusing on the scenarios that can produce the two commonly observed spectral evolution patterns: hard-to-soft evolution and intensity tracking, within a single emission pulse. The evolution is analysed using both Bayesian block and constant-fluence binning, with the observed spectrum modeled consistently using the Band function. Using this bottom-up approach, we find that optically thin ICS yields a positive $E_{\mathrm{peak}}$-$α$ correlation, with $α$ evolving from hard (Planck-like, $> +0.5$) to softer ($< -0.67$) values. Such hard $α$ values are inconsistent with standard synchrotron emission. This characteristic evolution in the $E_{\mathrm{peak}}$-$α$ plane, therefore, provides a diagnostic signature of optically thin ICS as the dominant radiation mechanism during the prompt phase of GRBs. Furthermore, this type of smooth evolution of $α$ within a single pulse does not require invoking a transition between different radiation mechanisms, unless additional observational evidence supports such a change.

astro-ph.HE↗
arXiv2026

Short Spike, Long Story: Episode-Dependent Shifts of Long-Duration Type-I GRBs on $E_{\rm p,z}$--$E_{\rm iso}$ Plane

Observations of peculiar GRBs have challenged the traditional $T_{90}$-based classification, demonstrating that duration does not map uniquely onto progenitor type. A striking class is long-duration Type~I GRBs -- merger-origin events whose prompt emission lasts far longer than the canonical 2 s boundary, typically comprising an initial short hard spike followed by softer extended emission. Identifying the physical origin of such bursts requires diagnostics beyond duration alone, among which the Amati relation, linking rest-frame spectral peak energy $E_{\rm p,z}$ and isotropic-equivalent energy $E_{\rm iso}$, is widely used as a complementary classification tool. We analyze a sample of eight long-duration Type~I GRBs and merger candidates by separating the initial spike from the extended emission and examining their episode-dependent locations on the $E_{\rm p,z}$--$E_{\rm iso}$ plane. We find that the initial spike generally lies within, or close to, the empirical Type~I region, consistent with a compact-merger-like prompt-emission component. In contrast, the extended-emission episode systematically occupies a region closer to Type~II GRBs, and could be misidentified as collapsar-like if analyzed in isolation. This episode-dependent Type~I-to-Type~II transition is further supported by time-resolved spectral analysis, although its magnitude and trajectory vary among bursts, suggesting diversity in central-engine evolution or outflow properties between the two phases. Our results caution that the Amati relation alone can lead to misleading empirical classification when the initial hard spike is weak, outside the instrumental bandpass, or missed entirely, leaving only the extended emission to be analyzed. Broad temporal and spectral coverage, and independent multi-wavelength diagnostics, is therefore essential for identifying the physical origin of these events.

astro-ph.HE↗