Progenitor Dependence of Neutrino-driven Supernova Explosions with the Aid of Heavy Axion-like Particles

TL;DR

This work investigates whether heavy axion-like particles (ALPs) that couple to photons can transport energy and modify the outcome of core-collapse supernovae (CCSNe). The authors perform self-consistent 1D SN simulations with ALP heating, cooling, and transport across a broad ALP parameter space ($m_a$ from 100 to 800 MeV and $g_{aγ}$ corresponding to $g_{10}=4-10$) for three progenitors ($11.2$, $20$, and $25\ M_⊙$), solving ALP production via Primakoff and photon coalescence and ALP transport with heating from ALP decay. They find that for $m_a\lesssim 300$ MeV, larger $g_{aγ}$ can induce shock revival by increasing ALP heating, whereas for $m_a\gtrsim 400$ MeV the production becomes Boltzmann-suppressed, diminishing heating and explodability; the heating peak occurs near $r\sim 10$ km and the explodability region is more extended for heavier progenitors. These results demonstrate that heavy ALPs can significantly affect the explodability and explosion energy in CCSNe and highlight the critical role of progenitor structure for interpreting potential multi-messenger signals from nearby SNe.

Abstract

We perform spherically symmetric simulations of core-collapse supernovae with the aid of heavy axion-like particles (ALPs) which interact with photons and redistribute energy within supernova matter. We explore a wide ALP parameter space that includes MeV-scale ALP mass $m_{\,a}$ and the ALP-photon coupling constant $g_{\,a γ} \sim 10^{\,-10} \, \rm{GeV}^{\,-1}$ , employing three progenitor models with zero-age main-sequence mass of $11.2\,M_\odot$, $20.0\,M_\odot$, and $25.0\,M_\odot$. We find a general trend that, given $m_{\,a}\lesssim 300\,$MeV, heavier ALPs are favorable for the shock wave to be successfully revived, aiding the onset of the neutrino-driven explosion. However, if ALPs are heavier than $\sim 400\,$MeV, the explosion is failed or weaker than that for the models with smaller $m_{\,a}$, because of an insufficient temperature inside the supernova core to produce heavy ALPs. The maximum temperature in the core depends on the initial progenitor structure. Our simulations indicate that the high-temperature environment in the collapsing core of massive progenitors leads to a significant impact of ALPs on the explodability.

Figures (11)

• Figure 1: The mass accretion rate, measured at $r=500\,\rm{km}$, is shown as a function of time after the core bounce $t_{\rm{pb}}$ for the no-ALP models. Here, the solid red, dotted magenta, and dashed green lines represent the $11.2M_{\odot}$, $20M_{\odot}$ and $25M_{\odot}$ progenitor models. The accretion rate decreases over time in all three models, with a pronounced drop when the Si/O interface falls onto the central region.
• Figure 2: The angular-averaged shock radii as functions of time for the s20_m2 model series. Shown are the models with ALPs with different coupling constants $g_{\rm{10}}=4,6,8\,\rm{and}\,10$, as labeled, as well as the no-ALP model (black solid line) represented as s20_m0_g00. For the s20_m2_g08 and s20_m2_g10 models (solid red and dotted magenta lines), the additional heating via ALP-photon interactions leads to the shock revival. Shock wave is more likely to be revived in models with higher coupling constants.
• Figure 3: The radial profile of the ALP heating rate $Q_{\rm{heat}}$ at $t_{\rm{pb}}= 170 \, \rm{ms}$ is shown. The color coding is the same as in Fig.\ref{['fig:sh20_200']}. That said, the black solid line represents the net neutrino heating rate $Q_{\nu} = Q_{\rm{heat}}^{\nu} - Q_{\rm{cool}}^{\nu}$, and the gray solid line represents the SN matter temperature for the s20 no-ALP model. A higher coupling constant leads to higher ALP heating rates, facilitating shock revival. For these ALP parameter sets, the neutrino heating rates dominate over the ALP heating rates in the gain region ($r\sim 60-80$ km), and neutrino heating is the main explosion mechanism.
• Figure 4: The neutrino luminosity (top panels) and the mean energy (bottom panels). The residuals relative to the no-ALP models are shown below each plot. The color coding is the same as in Fig.\ref{['fig:sh20_200']}. The higher coupling constant model shows that a greater reduction in the luminosity of all flavors and in the mean energy of $\nu_{e}$ and $\bar{\nu}_{e}$, because the shock expansion leads to a decrease in the mass accretion rate. On the other hand, the mean energy of $\nu_{x}$ is almost independent of the models. This is because $\nu_{x}$ is produced more in the central region than the neutrinos of other flavors, and $\nu_{x}$ is less influenced by the shock expansion. Before the shock expansion, the luminosity and the mean energy are not affected by ALPs, but they are influenced by the shock expansion, which is promoted by ALPs.
• Figure 5: The shock radius of the s20_g08 model series. Shown are the models with ALPs with different masses $(m_{a}=100,\, 200,\, 400\, \rm{and}\,600 \,\rm{MeV})$, as labeled, along with the model without ALPs (black solid line). The s20_m2_g08 and s20_m4_g08 models (dashed green and dotted magenta lines) exhibit shock revival. However, for the s20_m6_g08 model (solid red line) in which heavier ALPs are incorporated, the shock expansion is delayed compared to these two models. The tend of shock revival is not monotonic with respect to the ALP mass.