The synchrotron X-ray "stripes" discovered in Tycho's supernova remnant (SNR) have been attracting attention since they may be evidence for proton acceleration up to PeV. We analyzed Chandra data taken in 2003, 2007, 2009, and 2015 for imaging and spectroscopy of the stripes in the southwestern region of the SNR. Comparing images obtained at different epochs, we find that time variability of synchrotron X-rays is not limited to two structures previously reported but is more common in the region. Spectral analysis of nine bright stripes reveals not only their time variabilities but also a strong anti-correlation between the surface brightness and photon indices. The spectra of the nine stripes have photon indices of \Gamma = 2.1--2.6 and are significantly harder than those of the outer rim of the SNR in the same region with \Gamma = 2.7--2.9. Based on these findings, we indicate that the magnetic field is substantially amplified, and suggest that particle acceleration through a stochastic process may be at work in the stripes.

中文翻译：

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第谷超新星遗迹中同步加速器X射线条纹的时空变化

在第谷的超新星遗迹 (SNR) 中发现的同步加速器 X 射线“条纹”一直备受关注，因为它们可能是质子加速到 PeV 的证据。我们分析了 2003 年、2007 年、2009 年和 2015 年的钱德拉数据，用于 SNR 西南部地区条纹的成像和光谱。比较在不同时期获得的图像，我们发现同步加速器 X 射线的时间变异性不仅限于先前报道的两种结构，而且在该地区更为常见。九条亮条纹的光谱分析不仅揭示了它们的时间变化，而且揭示了表面亮度和光子指数之间的强烈反相关。九条条纹的光谱具有 \Gamma = 2.1--2.6 的光子指数，并且明显比在 \Gamma = 2 的同一区域内 SNR 的外边缘的光谱更硬。7--2.9。基于这些发现，我们表明磁场被显着放大，并表明通过随机过程的粒子加速可能在条纹中起作用。