Expansion measurements of supernova remnant RX J1713.7−3946

Abstract

Supernova remnant (SNR) RX J1713.7−3946 is well known for its bright TeV gamma-ray emission with shell-like morphology. Strong synchrotron X-ray emission dominates the total X-ray flux in SNR RX J1713.7−3946 and the X-ray morphology is broadly similar to the TeV gammaray appearance. The synchrotron X-ray and TeV gamma-ray brightness allows us to perform detailed analysis of the acceleration of TeV-scale particles in this SNR. To constrain the hydrodynamical evolution of RX J1713.7−3946, we have performed six times observations of the northwestern (NW) shell with the Chandra X-ray Observatory from 2005 to 2011, and measured the proper motion by using these data and the first epoch observation taken in 2000. The blast-wave shock speed at the NW shell is measured to be (3900 ± 300)(d/kpc) km swith an estimated distance of d = 1 kpc, and the proper motions of other structures within the NW shell are significantly less than that. Assuming that the measured blast-wave shock speed is the representative of the remnant's outer shock wave as a whole, we have confronted our measurements as well as a recent detection of thermal X-ray lines, with the analytic solution of the hydrodynamical properties of SNRs. Our hydrodynamical analysis indicates that the age of the remnant is 1580-2100 years, supporting the association with SN393. A model with SN kinetic energy of E = 10 51 erg, the ejecta mass of M ej = 3 M ⊙ , and the ambient density at the current blast wave location of n 2 = 0.015 cm −3 , provides reasonable explanation for our measurements and previous findings at the X-ray and gamma-ray wavelengths. We find that the transition to the Sedov-Taylor (ST) phase is incomplete for any reasonable set of parameters, implying that the current maximum energy of accelerated protons in RX J1713.7−3946 would not correspond to the maximum attainable energy for this remnant.

Solar system exposure to supernova γ radiation

“…G347.3-00.5 (Table 1) is a possible candidate for causation of the somewhat less intense CE 993 tree ring 14 C anomaly. It also was a close SN, very energetic at 10 51 erg (Tsuji and Uchiyama, 2016), and its age may be compatible with the anomaly date, given the uncertainties with distances and ages. In this regard, however, instead of any visible SN-like object, a survey of historical records from Ireland, Germany and Korea show several reports of possible auroral activity commencing on 26 December 992.…”

“…The magnitude of the younger 14 C event is 0.6 of the older, suggesting, if intrinsic energies of associated SNe were similar, that the younger SN was ~1.3× more distant. Plausible candidate SNe would be G347.3-00.5 at 1.3 ± 0.4 kpc and approximately 1840 ± 260 years in age (Tsuji and Uchiyama, 2016), and the recently discovered and elongated G190.9-2.2 at 1.0 ± 0.3 kpc (Foster et al ., 2013) (Table 1). Both are significantly closer than SN 1006 at ~1.56 kpc.…”

The interstellar medium in young supernova remnants: key to the production of cosmic X-rays and $\gamma $-rays

“…As the low velocity CO gas is fainter by an order of magnitude than the −69 and −94 km s −1 clouds, it was ignored by Slane et al (1999). The smaller distance is now widely accepted, and it has been established that RXJ1713 is a young SNR aged 1600 yr, which was historically recorded (Aha-ronian et al 2004;Cassam-Chenaï et al 2004;Tanaka et al 2008Tanaka et al , 2020Sano et al 2015a;Tsuji and Uchiyama 2016). This shows that high resolution and sensitivity are crucial in a comparison with the ISM, raising questions about the distance determinations in previous low-resolution studies.…”

“…4). This suggests that the distribution of the dense gas had a significant effect on regulating the X-ray distribution in the recent 1000 yr, assuming a shock velocity of ∼4000 km s −1 (c.f., Tsuji and Uchiyama 2016;Tanaka et al 2020), which has stimulated a detailed theoretical study of the interaction between a shock front and clumpy ISM. 2 2 According to proper-motion measurements of the Chandra X-rays, the shock speed is measured to be 3900 ± 300 km s −1 (Tsuji and Uchiyama 2016).…”

Detecting Thermal X-Ray Emission and Proper Motions in RX J1713.7-3946

“…Without information on the ISM, expansion measurements of the X-ray remnant would be the best hope for constraining the ambient densities. Tsuji & Uchiyama (2016) and Acero et al (2017) recently succeeded in measuring proper motions in the northwestern and the southeastern filaments, respectively. Here, we concisely review the results of Katsuda et al (2015) and Acero et al (2017), including new information on the analysis and discussions.…”