Suzaku Detection of Diffuse Hard X-Ray Emission outside Vela X

Abstract

Vela X is a large, 3x2 degrees, radio-emitting pulsar wind nebula (PWN) powered by the Vela pulsar in the Vela supernova remnant. Using four Suzaku/XIS observations pointed just outside Vela X, we find hard X-ray emission extending throughout the fields of view. The hard X-ray spectra are well represented by a power-law. The photon index is measured to be constant at Gamma~2.4, similar to that of the southern outer part of Vela X. The power-law flux decreases with increasing distance from the pulsar. These properties lead us to propose that the hard X-ray emission is associated with the Vela PWN. The larger X-ray extension found in this work strongly suggests that distinct populations relativistic electrons form the X-ray PWN and Vela X, as was recently inferred from multiwavelength spectral modeling of Vela X.

18 pages, 7 figures, accepted for publication in PASJ (Suzaku Special Issue)

References in corpus (11)

• First detection of a VHE gamma-ray spectral maximum from a Cosmic source: H.E.S.S. discovery of the Vela X nebula
• Fermi Large Area Telescope observations of the Vela-X Pulsar Wind Nebula
• Probing the radio to X-ray connection of the Vela X PWN with Fermi LAT and H.E.S.S
• X-ray Evolution of Pulsar Wind Nebulae
• Probing the Nature of the Vela X Cocoon
• Detection of Gamma-Ray Emission from the Vela Pulsar Wind Nebula with AGILE
• Physical and chemical inhomogeneities inside the Vela SNR shell. Indications of ejecta shrapnels
• Non-Thermal X-ray Emission from the Northwestern Rim of the Galactic Supernova Remnant G266.2-1.2 (RX J0852.0-4622)
• Spatially Resolved X-ray Spectroscopy of Vela Shrapnel A
• Shock-cloud interaction in the Vela SNR II. Hydrodynamic model
• X-Ray Studies of HESS J1809-193 with Suzaku

Cited by in corpus (10)

• Pulsar wind nebulae with bow shocks: non-thermal radiation and cosmic ray leptons
• Probing the extent of the non-thermal emission from the Vela X region at TeV energies with H.E.S.S
• H.E.S.S. and Suzaku observations of the Vela X pulsar wind nebula
• Investigating the Structure of Vela X
• A detailed look at the thermal and non-thermal X-ray emission from the Vela supernova remnant with SRG/eROSITA
• Suzaku observations of the hard X-ray spectrum of Vela Jr
• X-ray investigation of the diffuse emission around plausible gamma-ray emitting pulsar wind nebulae in Kookaburra region
• Numerical simulations of composite supernova remnants for small $\sigma$ pulsar wind nebulae
• X-ray emitting structures in the Vela SNR: ejecta anisotropies and progenitor stellar wind residuals
• Global X-Ray Properties of the Vela and Puppis A Supernova Remnants