The high-energy emission from HD 93129A near periastron
S. del palacio ... [et al.].
Serie: Trabajos publicados del IAR ; no. 1550
Resumen: We conducted an observational campaign towards one of the most massiveand luminous colliding wind binaries in the Galaxy, HD 93129A, close toits periastron passage in 2018. During this time the source waspredicted to be in its maximum of high-energy emission. Here we presentour data analysis from the X-ray satellites Chandra and NuSTAR and theγ-ray satellite AGILE. High-energy emission coincident with HD 93129Awas detected in the X-ray band up to ∼18 keV, whereas in the γ-ray bandonly upper limits were obtained. We interpret the derived fluxes using anon-thermal radiative model for the wind-collision region. We establisha conservative upper limit for the fraction of the wind kinetic powerthat is converted into relativistic electron acceleration,fNT,e < 0.02. In addition, we set a lower limit for themagnetic field in the wind-collision region as BWCR > 0.3G. We also argue a putative interpretation of the emission from which weestimate fNT,e ≠0.006 and BWCR ≠0.5 G. Weconclude that multiwavelength, dedicated observing campaigns duringcarefully selected epochs are a powerful tool for characterizing therelativistic particle content and magnetic field intensity in collidingwind binaries.