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arXiv 1405.6463astro-ph.HEastro-ph.SR
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第谷超新星遗迹的硬X射线发射和$^{44}$ Ti线特征

Hard X-ray emission and $^{44}$Ti line features of Tycho Supernova Remnant

Wei Wang, Zhuo Li

摘要:

INTEGRAL卫星的深硬X射线测量首次在第谷超新星(SN)遗迹中探测到高达90 keV的非热发射。它的3 - 100 keV的光谱与热韧致辐射的$kT\sim 0.81\pm 0.45$ keV加上幂律模型的$Γ\sim 3.01\pm 0.16$。基于扩散激波加速理论,这种非热辐射,加上射电测量,意味着第谷遗迹可能不会加速质子高达$>$ PeV,但数百TeV。只有较重的原子核才可能被加速到宇宙射线的光谱“膝盖”。此外,我们还用INTEGRAL方法寻找了第谷遗迹中放射性$^{44}$ Ti衰变产生的67.9和78.4 keV的软γ射线。在60-90 keV的能带,可能与$^{44}$ Ti线发射,发现一个凸点功能与边缘显著性水平为$\sim$ 2.6 $σ$。$^{44}$ Ti线通量的相应3 $σ$上限为1.5 $\times$ 10 $^{-5}$ ph cm $^{-2}$ s $^{-1}$。讨论了被认为是Ia型SN原型的第谷SN的起源的意义。

英文摘要:

A deep hard X-ray survey of the INTEGRAL satellite first detected the non-thermal emission up to 90 keV in the Tycho supernova (SN) remnant. Its 3 -- 100 keV spectrum is fitted with a thermal bremsstrahlung of $kT\sim 0.81\pm 0.45$ keV plus a power-law model of $Γ\sim 3.01\pm 0.16$. Based on the diffusive shock acceleration theory, this non-thermal emission, together with radio measurements, implies that Tycho remnant may not accelerate protons up to $>$PeV but hundreds TeV. Only heavier nuclei may be accelerated to the cosmic ray spectral "knee". In addition, we search for soft gamma-ray lines at 67.9 and 78.4 keV coming from the decay of radioactive $^{44}$Ti in Tycho remnant by INTEGRAL. A bump feature in the 60-90 keV energy band, potentially associated with the $^{44}$Ti line emission, is found with a marginal significance level of $\sim$ 2.6 $σ$. The corresponding 3 $σ$ upper limit on the $^{44}$Ti line flux amounts to 1.5 $\times$ 10$^{-5}$ ph cm$^{-2}$ s$^{-1}$. Implications on the progenitor of Tycho SN, considered to be the prototype of type Ia SN, are discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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