Internal entrainment and the origin of jet-related broad-band emission in Centaurus A

Abstract

The dimensions of Fanaroff-Riley class I jets and the stellar densities at galactic centres imply that there will be numerous interactions between the jet and stellar winds. These may give rise to the observed diffuse and 'knotty' structure of the jets in the X-ray, and can also mass load the jets. We performed modelling of internal entrainment from stars intercepted by Centaurus A's jet, using stellar evolution- and wind codes. From photometry and a code-synthesised population of 12 Gyr (Z = 0.004), 3 Gyr (Z = 0.008) and 0 - 60 Myr (Z = 0.02) stars, appropriate for the parent elliptical NGC 5128, the total number of stars in the jet is ~ 8 x 10^8. Our model is energetically capable of producing the observed X-ray emission, even without young stars. We also reproduce the radio through X-ray spectrum of the jet, albeit in a downstream region with distinctly fewer young stars, and recover the mean X-ray spectral index. We derive an internal entrainment rate of ~ 2.3 x 10^-3 Msun yr^-1 which implies substantial jet deceleration. Our absolute nucleosynthetic yields for the AGB stellar population in the jet show the highest amounts for 4He, 16O, 12C, 14N and 20Ne. If some of the events at >= 55 EeV detected by the Pierre Auger Observatory originate from internal entrainment in Centaurus A, we predict that their composition will be largely intermediate-mass nuclei with 16O, 12C and 14N the key isotopes.

14 pages, 4 figures. Minor updates to match accepted version. Accepted by MNRAS

References in corpus (15)

• Galactic chemical evolution: Carbon through Zinc
• The present-day star formation rate of the Milky-Way determined from Spitzer detected young stellar objects
• The Galactic WC stars: Stellar parameters from spectral analyses indicate a new evolutionary sequence
• Luminous Blue Variables are Antisocial: Their Isolation Implies that they are Kicked Mass Gainers in Binary Evolution
• Luminous Blue Variables as the progenitors of supernovae with quasi-periodic radio modulations
• High-energy particle acceleration at the radio-lobe shock of Centaurus A
• The mass of the black hole in Centaurus A from SINFONI AO-assisted integral-field observations of stellar kinematics
• On the deceleration of FRI jets: mass loading by stellar-winds
• New results on particle acceleration in the Centaurus A jet and counterjet from a deep Chandra observation
• TANAMI monitoring of Centaurus A: The complex dynamics in the inner parsec of an extragalactic jet
• The Suzaku Observation of the Nucleus of the Radio-Loud Active Galaxy Centaurus A: Constraints on Abundances of the Accreting Material
• AGN Jet Mass Loading and Truncation by Stellar Winds
• The infrared jet in Centaurus A: multiwavelength constraints on emission mechanisms and particle acceleration
• Where Centaurus A gets its X-ray knottiness
• Filaments in the southern giant lobe of Centaurus A: constraints on nature and origin from modelling and GMRT observations

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