X-ray investigation of the diffuse emission around plausible gamma-ray emitting pulsar wind nebulae in Kookaburra region

Abstract

We report on the results from {\it Suzaku} X-ray observations of the radio complex region called Kookaburra, which includes two adjacent TeV $\gamma$-ray sources HESS J1418-609 and HESS J1420-607. The {\it Suzaku} observation revealed X-ray diffuse emission around a middle-aged pulsar PSR J1420-6048 and a plausible PWN Rabbit with elongated sizes of ${\sigma }_{\mathrm{X}}=1^{\prime }.66$ and ${\sigma }_{\mathrm{X}}=1^{\prime }.49$, respectively. The peaks of the diffuse X-ray emission are located within the $\gamma$-ray excess maps obtained by H.E.S.S. and the offsets from the $\gamma$-ray peaks are $2^{\prime }.8$ for PSR J1420-6048 and $4^{\prime }.5$ for Rabbit. The X-ray spectra of the two sources were well reproduced by absorbed power-law models with $\Gamma =1.7-2.3$. The spectral shapes tend to become softer according to the distance from the X-ray peaks. Assuming the one zone electron emission model as the first order approximation, the ambient magnetic field strengths of HESS J1420-607 and HESS J1418-609 can be estimated as 3 $\mu$G, and $2.5\mu$G, respectively. The X-ray spectral and spatial properties strongly support that both TeV sources are pulsar wind nebulae, in which electrons and positrons accelerated at termination shocks of the pulsar winds are losing their energies via the synchrotron radiation and inverse Compton scattering as they are transported outward.

To appear in ApJ

References in corpus (5)

• Pulsar Wind Nebulae in the Chandra Era
• Fermi-LAT Search for Pulsar Wind Nebulae around gamma-ray Pulsars
• Multi-Zone Modeling of The Pulsar Wind Nebula HESS J1825-137
• The radiative X-ray and gamma-ray efficiencies of rotation powered pulsars
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Cited by in corpus (7)

• Constraints on the Galactic Population of TEV Pulsar Wind Nebulae Using Fermi Large Area Telescope Observations
• The soft gamma-ray pulsar population: an high-energy overview
• Search for PeV Gamma-Ray Emission from the Southern Hemisphere with 5 Years of Data from the IceCube Observatory
• Connecting the ISM to TeV PWNe and PWNe candidates
• A broadband X-ray study of the Rabbit pulsar wind nebula powered by PSR J1418-6058
• X-ray studies of the pulsar PSR J1420-6048 and its TeV pulsar wind nebula in the Kookaburra region
• The power-law component of the X-ray emissions from pulsar wind nebulae and their pulsars