[論文レビュー] The Persistent Radio Sources and Multi-wavelength Counterparts of Fast Radio Bursts in Massive Binary Systems

Z. Y. Zhao, F. Y. Wang+1 more|arXiv (Cornell University)|Mar 24, 2026

Pulsars and Gravitational Waves Research被引用数 0

ひとこと要約

The paper develops a magnetar–massive-star binary framework to explain persistent radio sources (PRSs) and multi-wavelength bow-shock counterparts to FRBs, including radio to TeV emissions and DM/RM evolution.

ABSTRACT

Fast radio bursts (FRBs) are millisecond-duration pulses originating from cosmological distances. Multi-wavelength counterparts associated with FRBs are important for unveiling their physical origins. Recent observations provide strong evidence that the sources of some active FRBs are residing in massive star binaries. In this paper, we study the electromagnetic counterparts of FRBs, including the persistent radio sources (PRSs) and the bow shock radiation from wind collisions for FRBs residing in magnetar - massive star binaries. We find that the PRSs with luminosity $10^{38}-10^{39}$ erg s$^{-1}$ can be generated by young magnetar wind nebulae (MWN). The age of magnetars is a few decades. The observed long-term variation of flux density for PRSs can be explained by the internal magnetic field decay of magnetars. The bow shock radiation can account for the less luminous PRS of FRB 20201124A. The multi-wavelength emission arising from synchrotron radiation and inverse-Compton scattering in the bow shock can be the electromagnetic counterpart of FRBs. The emission at keV, GeV and TeV bands from the binary model can be detected at the distances of $\sim10-100$ Mpc, $\sim 1-10$ Mpc and $\sim0.1$ Mpc by current instruments, respectively.

研究の動機と目的

• Motivate and model the electromagnetic counterparts of FRBs residing in magnetar–massive-star binaries, focusing on PRSs and bow-shock radiation.
• Link PRS properties to magnetar wind nebula (MWN) evolution and to wind–wind interactions in binaries.
• Explain observed PRS luminosities and long-term flux variations through magnetar internal magnetic field decay and MWN dynamics.
• Predict multi-wavelength emission signatures from bow shocks and assess their detectability with current instruments.

提案手法

• Develop a binary-centered MWN model where magnetar spin-down and internal magnetic energy inject into a nebula expanding inside SN ejecta.
• Derive nebula evolution equations for radius and magnetic energy considering energy injection, adiabatic losses, and expansion.
• Model electron distributions in MWN with a broken power law and solve the continuity equation to obtain nonthermal spectra.
• Compute bow-shock radiation from magnetar wind interacting with companion stellar wind, including synchrotron and inverse-Compton (SSC and EIC) components.
• Estimate free-free absorption, SSA, and gamma-gamma opacity to constrain viable binary parameters for PRS production.
• Compare predicted PRS luminosities with observed FRB PRS cases and discuss observational consequences across radio to gamma-ray bands.

Figure 1 : Schematic diagram of repeating FRBs’ environments. a, The magnetar/massive star binary is embedded in a supernova remnant. b, The case of a stronger magnetar wind ( $\eta\gg 1$ ), the shock bends back to the star. The magnetar wind will propagate freely, especially in the direction perpen

実験結果

リサーチクエスチョン

• RQ1 What are the physical conditions under which magnetar winds in massive binary systems produce observable PRSs with luminosities in the 10^38–10^39 erg s^-1 range?
• RQ2 How does wind–wind interaction in a magnetar–massive-star binary generate bow-shock emission across radio to TeV bands, and what are the expected DM/RM signatures?
• RQ3 Can the bow-shock model explain faint PRSs like those associated with FRB 20201124A and FRB 20181030A while remaining consistent with free-free absorption constraints?
• RQ4 What parameter space (orbital period, companion mass, wind properties) yields detectable multi-wavelength counterparts given current instrument sensitivities?

主な発見

• Bright PRSs with νLν > 10^39 erg s^-1 are unlikely to be produced in binaries with typical orbital separations and massive companions.
• Faint PRSs (e.g., FRB 20201124A-like) can be produced in systems with orbital periods of several hundred days and companion masses >10 M⊙.
• MWN evolution powered by a young magnetar with strong internal magnetic fields (>10^16 G) can sustain PRS luminosities over ~1–100 years, aligning with observed long-term stability.
• Bow-shock emission in the binary model yields multi-wavelength spectra from radio to TeV, with keV X-rays from bow-shock synchrotron emission being detectable at ~10 Mpc distances by Chandra/XMM-Newton.
• The maximum electromagnetic output in the bow-shock model scales with wind parameters and separation, and the geometry can allow free-expanding magnetar wind to dominate in directions perpendicular to the orbital plane.
• Gamma-ray emission components (SSC, EIC) contribute alongside synchrotron radiation, with optical depths (SSA and γγ) shaping observable spectra.

Figure 2 : The value of $L_{\mathrm{syn}}$ for different companion mass $M_{\star}$ and orbital periods $P$ . The magnetization parameter $\sigma=0.01$ is adopted in our calculation. The free–free absorption optically thick regions for $\nu=1$ GHz have been excluded (shown in gray). The blue, red an