Constraint on the Physical Origin of Gamma-Ray Burst Prompt Emission via Its Nondetected Diffuse Neutrino Emission

TL;DR

The paper tackles the problem of identifying the dominant origin of GRB prompt emission by leveraging nondetected diffuse neutrinos and IceCube upper limits. It employs two calculation frameworks—summing neutrino contributions from observed GRBs and integrating over a GRB luminosity function—under benchmark parameters $\Gamma=300$ and $\varepsilon_p/\varepsilon_e=10$ to constrain the fractions of dissipative photosphere, internal shocks, and ICMART models. The results strongly favor the ICMART scenario, with dissipative photosphere and internal shocks confined to a small parameter space, though exact fractions depend on $\Gamma$ and $\varepsilon_p/\varepsilon_e$. This multimessenger approach provides a complementary probe of GRB jet composition and magnetic energy dissipation, while highlighting sensitivity to dissipation radii assumptions and redshift uncertainties. Overall, the work supports a magnetized, large-radius dissipation origin for most GRB prompt emissions, guiding future observational and theoretical efforts.

Abstract

The physical origin of prompt emission in gamma-ray bursts (GRBs) remains an open question since it has been studied more than half a century. Three alternative models (i.e. dissipative photosphere, internal shock, and Internal-Collision-induced MAgnetic Reconnection and Turbulence, ICMART) have been proposed to interpret the observations of GRB prompt emission, but none of them can fully interpret all of the observational data collected so far. The question is what is the fraction of these three theoretical models in the prompt emission of GRBs. In this paper, we propose to utilize an innovative method and constrain the fraction of GRB prompt emission models via its nondetected diffuse neutrinos. By adopting two methods (e.g., summing up the individual GRB contributions and assumed luminosity functions of GRB) to calculate diffuse neutrino flux of GRBs for given the benchmark parameters of $Γ=300$ and $\varepsilon_{p} \text{/} \varepsilon_{e}=10$, both approaches indicate that most GRBs should be originated from the ICMART model. Moreover, we find that the fractions of the dissipative photosphere model, the internal shock model, and the ICMART model are constrained to be [0, $0.5\%$], [0, $1.1\%$], and [$98.9\%$, 1], respectively, for the method of summing up the individual GRB contributions. For the method of luminosity functions, the fractions of above three models are constrained to be [0, $6.1\%$], [0, $8.2\%$], and [$91.8\%$, 1], respectively. However, such fractions of different models are also dependent on the parameters of $Γ$ and $\varepsilon_{p} \text{/} \varepsilon_{e}$.

Figures (4)

• Figure 1: Predicted flux of diffuse neutrino for the benchmark parameters of $\varepsilon_{p} \text{/} \varepsilon_{e} = 10$ and $\Gamma = 300$ by assuming that all GRBs are originated from the signal model (e.g., the dissipative photosphere model, the internal shock model, and the ICMART model). The bands for the diffuse neutrino flux are displayed for $\varepsilon_{p} \text{/} \varepsilon_{e} = 3-10$ and $\Gamma = 100-500$. The gray line with arrows is the upper limit flux of diffuse neutrino. Left: results using the method of summing up the individual GRB contributions. Right: results using the method of assumed luminosity functions of the GRB.
• Figure 2: Constraint on the fraction of GRB prompt emission models by adopting the method of summing up the individual GRB contributions. Left: the constraint results for the varying value of $\Gamma=$ 300 and 500 with fixed $\varepsilon _{p } \text{/} \varepsilon _{e } = 10$. Right: the constraint results for the varying value of $\varepsilon _{p } \text{/} \varepsilon _{e }=3$, 5, and 10 with fixed $\Gamma = 300$.
• Figure 3: Constraint on the fraction of GRB prompt emission models by adopting the method of assumed luminosity functions of GRB. Left: the constraint results for the varying value of $\Gamma=$ 300 and 500 with fixed $\varepsilon _{p } \text{/} \varepsilon _{e } = 10$. Right: the constraint results for the varying value of $\varepsilon _{p } \text{/} \varepsilon _{e }=$ 5 and 10 with fixed $\Gamma = 300$.
• Figure 4: Predicted flux of diffuse neutrino for the benchmark parameters of $\varepsilon_{p} \text{/} \varepsilon_{e} = 10$ and $\Gamma = 300$ by assuming that all GRBs are originated from signal model with different mean redshift. Left: changed the mean redshift of short GRBs as $z=0.3$, 0.5, and 1.0 for fixed $z=2.15$ of long GRBs. Middle: changed the mean redshift of long GRBs as $z=1.0$, 2.0, and 3.0 for fixed $z=0.5$ of short GRBs. Right: simultaneously increasing the redshift of long GRBs ($z=1.0$, 2.0, and 3.0) and short GRBs ($z=0.25$, 0.5, and 1.0).