| Journal Title /掲載ジャーナル名 |
Astrophysical Journal Letters |
| Publication Year and Month /掲載年月 |
July, 2024 |
| Paper Title /論文タイトル |
Observational Evidence for Magnetic Field Amplification in SN 1006 |
| DOI /論文DOI |
10.3847/2041-8213/ad60c7 |
| Author of Waseda University /本学の著者 |
KATAOKA, Jun(Professor, Faculty of Science and Engineering, School of Advanced Science and Engineering):Lasr Author |
| Related Websites /関連Web |
– |
| Abstract /抄録 |
We report the first observational evidence for magnetic field amplification in the northeast/southwest (NE/SW) shells of supernova remnant SN 1006, one of the most promising sites of cosmic ray acceleration. In previous studies, the strength of magnetic fields in these shells was estimated to be BSED ≃ 25 μG from the spectral energy distribution, where the synchrotron emission from relativistic electrons accounted for radio to X-rays, along with the inverse Compton emission extending from the GeV to TeV energy bands. However, the analysis of broadband radio data, ranging from 1.37 to 100 GHz, indicated that the radio spectrum steepened from α1 = 0.52 ± 0.02 to α2 = 1.34 ± 0.21 by Δα = 0.85 ± 0.21. This is naturally interpreted as a cooling break under a strong magnetic field of Bbrk ≥ 2 mG. Moreover, the high-resolution MeerKAT image indicated that the width of the radio NE/SW shells was broader than that of the X-ray shell by a factor of only 3−20, as measured by Chandra. Such narrow radio shells can be naturally explained if the magnetic field responsible for the radio emissions is BR ≥ 2 mG. Assuming that the magnetic field is locally enhanced by a factor of approximately a = 100 along the NE/SW shells, we argue that the filling factor, which is the volume ratio of such a magnetically enhanced region to that of the entire shell, must be as low as approximately k = 2.5 × 10−5. |
