The structure of TeV-bright shell-type supernova remnants

Yang, Chengguang; Liu, Siming; Fang, Jun; Li, Hui

doi:10.1051/0004-6361/201424667

Cited by 7 publications

(2 citation statements)

References 56 publications

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“…The morphology of a SNR relates heavily to the ambient environment that is influenced by the progenitor system (see Wang & Han 2012, for a review of the progenitors of Type Ia supernovae). A non-uniform medium has been used to explain the detected asymmetries of SNRs through either analytical treatments (Hnatyk & Petruk 1999) or numerical simulations (e.g., Orlando et al 2007;Fang et al 2014;Yang et al 2015). Moreover, Guo et al (2012) employed 2D magnetohydrodynamic (MHD) simulations to investigate the amplification of magnetic fields for a SNR propagating into a turbulent plasma with the 2D Kolmogorov-like power spectrum.…”

Section: Introductionmentioning

confidence: 99%

Three-dimensional magnetohydrodynamic studies of the non-thermal X-ray morphologies of SN 1006

Fang

Zhang

et al. 2015

A&A

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Context. The observations of the synchrotron emission from the supernova remnant (SNR) SN 1006 indicate a bilateral morphology, which is mainly characterized by two opposite bright limbs with knots and filaments along the boundary of the remnant. The morphology is not strictly circular with disturbances and bumps at the rim of the remnant. For instance, one big bump is located on the northeastern (NE) limb and several relatively small ones on the southwestern (SW) limb on the detected morphologies from the observations in the radio and X-rays. Aims. The generation of the asymmetric morphology of non-thermal X-rays for SN 1006 is investigated through three-dimensional (3D) magnetohydrodynamic simulations. Moreover, the density distribution of the ambient material can be investigated by comparing the resulting synchrotron morphology with the detected images of the hard X-ray emission. Methods. First, the remnant was simulated as a supernova explosion evolved in a turbulent plasma with a relatively small amplitude for the turbulence. In the model, several spherical cavities with lower densities compared with the background plasma were employed to reproduce the detected bumps at the bright limbs. Second, the effect of the modification on the morphology of the remnant due to efficient cosmic ray acceleration was investigated by adopting a lower adiabatic index. Results. If we assume that the injection efficiency of electrons into the diffusive shock acceleration process at the shock follows the quasi-parallel scenario, the hard X-ray morphology of SN 1006 with bumps in the bright NE and SW regions can be generally reproduced by employing cavities in the background medium in the non-modification scenario. Furthermore, in the modification case with a lower adiabatic index of 1.2 for the remnant evolved in a uniform medium, bubbles can be produced with relatively small extensions on the SNR boundary that result from the hydrodynamical instabilities that in turn overtake the forward shock. Conclusions. The SNR propagating in the turbulent medium with a relatively small amplitude can reproduce the knotty and filamentary morphology of the remnant better than what evolved in the uniform environment; moreover, the big bump on the NE limb can be explained as the result of a lower-density region, which has a radius of about 2.5 pc and a density of about 0.4 times of the general ambient medium, swept by the shock front, and the other smaller ones on the SW limb can either be reproduced with smaller regions with lower densities swept by the shock or be explained as the protrusions in the scenario of the efficient cosmic ray acceleration when the instability fingers effectively overtake the forward shock.

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Section: Introductionmentioning

confidence: 99%

Three-dimensional magnetohydrodynamic studies of the non-thermal X-ray morphologies of SN 1006

Fang

Zhang

et al. 2015

A&A

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“…And they have harder GeV spectra and are usually brighter in the TeV band than in the GeV band. The γ-ray emission from these SNRs are usually believed to be leptonic (Yuan et al 2012;Funk 2015;Yang et al 2015), although there are debates for some of them (Inoue et al 2012;Gabici & Aharonian 2014). However, all these SNRs emit significant non-thermal X-ray emissions that are very different from HESS J1640-465 which no any non-thermal X-ray emission detected from the shell of SNR G338.3-0.0.…”

Section: Discussionmentioning

confidence: 99%

HESS J1640-465: A Gamma-Ray Emitting Pulsar Wind Nebula?

Xin

Liao

Guo

et al. 2018

ApJ

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HESS J1640-465 is an extended TeV γ-ray source and its γ-ray emission whether from the shell of a supernova remnant (SNR) or a pulsar wind nebula (PWN) is still under debate. We reanalyze the GeV γ-ray data in the field of HESS J1640-465 using eight years of Pass 8 data recorded by the Fermi Large Area Telescope. An extended GeV γ-ray source positionally coincident with HESS J1640-465 is found. Its photon spectrum can be described by a power-law with an index of 1.42 ± 0.19 in the energy range of 10-500 GeV, and smoothly connects with the TeV spectrum of HESS J1640-465. The broadband spectrum of HESS J1640-465 can be well fit by a leptonic model with a broken power-law spectrum of electrons with an exponential cut-off at ∼ 300 TeV. The spectral properties of HESS J1640-465 are broadly consistent with the characteristics of other sources identified as PWNe, such as the correlations between high-energy luminosity ratios and the physical parameters of pulsar, including spin-down luminosityĖ and characteristic age τ c . All these pieces of evidence support that the γ-ray emission of HESS J1640-465 may originate from the PWN powered by PSR J1640-4631 rather than the shell of the SNR G338.3-0.0.

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