Modeling the effects of clumpy winds in the high-energy light curves of γ-ray binaries

Abstract

High-mass gamma-ray binaries are powerful nonthermal galactic sources, some of them hosting a pulsar whose relativistic wind interacts with a likely inhomogeneous stellar wind. So far, modeling these sources including stellar wind inhomogeneities has been done using either simple analytical approaches or heavy numerical simulations, none of which allow for an exploration of the parameter space that is both reasonably realistic and general. Applying different semi-analytical tools together, we study the dynamics and high-energy radiation of a pulsar wind colliding with a stellar wind with different degrees of inhomogeneity to assess the related observable effects. We computed the arrival of clumps to the pulsar wind-stellar wind interaction structure using a Monte Carlo method and a phenomenological clumpy-wind model. The dynamics of the clumps that reach deep into the pulsar wind zone was computed using a semi-analytical approach. This approach allows for the characterization of the evolution of the shocked pulsar wind region in times much shorter than the orbital period. With this three-dimensional information about the emitter, we applied analytical adiabatic and radiative models to compute the variable high-energy emission produced on binary scales. An inhomogeneous stellar wind induces stochastic hour-timescale variations in the geometry of the two-wind interaction structure on binary scales. Depending on the degree of stellar wind inhomogeneity, 10-100% level hour-scale variability in the X-rays and gamma rays is predicted, with the largest variations occurring roughly once per orbit. Our results, based on a comprehensive approach, show that present X-ray and future very-high-energy instrumentation can allow us to trace the impact of a clumpy stellar wind on the shocked pulsar wind emission in a gamma-ray binary.

10 pages, 9 figures Accepted in A&A on October 23, 2022

References in corpus (27)

• Mass loss from hot massive stars
• Understanding the Very High-Energy Emission from Microquasars
• Modeling interaction of relativistic and nonrelativistic winds in binary system PSR 1259-63/SS2883. I.Hydrodynamical limit
• Accretion vs colliding wind models for the gamma-ray binary LS I +61 303: an assessment
• On the formation of TeV radiation in LS 5039
• TeV lightcurve of PSR B1259-63/SS2883
• Orbital X-Ray Variability of the Microquasar LS 5039
• Modeling Ultraviolet Wind Line Variability in Massive Hot Stars
• The modulation of the gamma-ray emission from the binary LS 5039
• A Clumping Independent Diagnostic of Stellar Mass-loss Rates: Rapid Clump Destruction in Adiabatic Colliding Winds
• On the interaction of microquasar jets with stellar winds
• Orbital evolution of colliding star and pulsar winds in 2D and 3D; effects of: dimensionality, EoS, resolution, and grid size
• Sign of hard X-ray pulsation from the gamma-ray binary system LS 5039
• Non-thermal emission from secondary pairs in close TeV binary systems
• Hadronic model for radio-to-TeV gamma-ray emission from PSR B1259-63
• NuSTAR observation of LS 5039
• Relativistic fluid modelling of gamma-ray binaries. I. The model
• Upper Mass-Loss Limits and Clumping in the Intermediate and Outer Wind Regions of OB stars
• Modelling the interaction between relativistic and non-relativistic winds in binary pulsar systems: strong magnetization of the pulsar wind
• Simulations of an inhomogeneous stellar wind interacting with a pulsar wind in a binary system
• Global Simulations of the Interaction of Microquasar Jets with a Stellar Wind in High-Mass X-ray Binaries
• Relativistic fluid modelling of gamma-ray binaries. II. Application to LS 5039
• A dynamical and radiation semi-analytical model of pulsar-star colliding winds along the orbit: Application to LS 5039
• Gamma rays from jets interacting with BLR clouds in blazars
• 3D RMHD simulations of jet-wind interactions in High Mass X-ray Binaries
• Properties of a hypothetical cold pulsar wind in LS~5039
• The major role of eccentricity in the evolution of colliding pulsar-stellar winds

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• High-Resolution Simulations of LS 5039
• Unveiling properties of the non-thermal X-ray production in the gamma-ray binary LS 5039 using the long-term pattern of its fast X-ray variability
• Achromatic rapid flares in hard X-rays in the $\gamma$-ray binary LS I +61-303
• Orbital Phase-resolved Analysis of X-ray and Gamma-ray Observations of the High-Mass Gamma-ray Binary 4FGL J1405.1-6119