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arXiv · 2003.10035

Time Variability of Nonthermal X-ray Stripes in Tycho's Supernova Remnant with Chandra

Tomoyuki Okuno·Takaaki Tanaka·Hiroyuki Uchida·Felix A. Aharonian·Yasunobu Uchiyama·Takeshi Go Tsuru·Masamune Matsuda
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Abstract

Analyzing Chandra data of Tycho's supernova remnant (SNR) taken in 2000, 2003, 2007, 2009, and 2015, we search for time variable features of synchrotron X-rays in the southwestern part of the SNR, where stripe structures of hard X-ray emission were previous found. By comparing X-ray images obtained at each epoch, we discover a knot-like structure in the northernmost part of the stripe region became brighter particularly in 2015. We also find a bright filamentary structure gradually became fainter and narrower as it moved outward. Our spectral analysis reveal that not only the nonthermal X-ray flux but also the photon indices of the knot-like structure change from year to year. During the period from 2000 to 2015, the small knot shows brightening of $\sim 70\%$ and hardening of $ΔΓ\sim 0.45$. The time variability can be explained if the magnetic field is amplified to $\sim 100~\mathrm{μG}$ and/or if magnetic turbulence significantly changes with time.

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Tomoyuki Okuno, Takaaki Tanaka, Hiroyuki Uchida, Felix A. Aharonian, Yasunobu Uchiyama, Takeshi Go Tsuru, Masamune Matsuda. 2020-04-15. Time Variability of Nonthermal X-ray Stripes in Tycho's Supernova Remnant with Chandra. https://doi.org/10.3847/1538-4357%2Fab837e

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