Old Supernova Remnants and Pulsar Wind Nebulae Long

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Old Supernova Remnants and Pulsar Wind Nebulae Long, K. , Bamba, A. , Hughes,

Old Supernova Remnants and Pulsar Wind Nebulae Long, K. , Bamba, A. , Hughes, J. , Katsuda, S. , Minami, S. , Mori, K. , Safi-Harb, S. , Sawada, M. , Tsunemi, H. , Uchida, H. , Yamauchi, S. , Aharonian, F. , Foster, A. , Funk, S. , Hiraga, J. , Ishida, M. , Matsumoto, H. , Nakajima, H. , Nakamori, T. , Nobukawa, M. , Ozaki, M. , Petre, R. , Tamagawa, T. , Tamura, K. , Tanaka, T. , Uchiyama, Y. Top Science: The physics of old SNRs and their effect on the ISM Topic: Charge Exchange and Resonance Scattering Effects Topic: Measuring the Absolute Abundance of SNR Ejecta Topic: Measuring Cooling of Recombining Plasma by Katsuda, Uchida, Tsunemi Recent Studies of Cygnus loop shows the possibility of presence of charge exchange (CX: Katsuda+11) and resonance scattering (RS) effects in the plasma emission (Miyata+08). CX: by neutrals (ISM) and ionized particles heated by shock -> only around the shock RS: by column density of the plasma -> important at the bright (inner) shell -> comparisons of spectra on the shock and inside can resolve these two processes ! Conventional X-ray CCD dataset showed us that the ejecta emission from old SNRs are over-abundant, but we have measured only lower limits of the abundances (Katsuda+05). If the ejecta abundance is several solar: The main component of the plasma is Hydrogen -> k. Ti ~ k. TH (low) If the ejecta abundance is super solar: The main component of the plasma is heavy element -> k. Ti ~ k. Theavy (high) -> We can measure the absolute abundance from the line width. Best Target: Cygnus loop Best Target: Vela Shrapnel D r/R=0. 99 region Enough bright for CX+RS contribution (the most studied region in Cyg. Loop Free from Doppler broadening due to shell expansion where possible CX effect is reported. ) -> Vela Shrapnel D is the best ! We selected the brightest region. r/R=0. 95 region for RS contribution (bright region just inner the r/R=0. 99) Fig 1. NE rim of Cygnus loop with SXS FOV. Shock velocity is assumed 500 km/s, from X-ray study (Aschenbach+95). RS affects the ratio of forbidden and resonance lines, depending on the plasma turbulence and abundance. 0. 4 0. 5 0. 6 Pure metal case (106 solar) -> expected k. Ti = 8 ke. V 0. 7 F/R = 1. 10 +/- 0. 085 F/R = 1. 02 +/- 0. 07 Fig. 3. 20 ks sim. for r/R=0. 95 region for RS measurement (left) and 30 ks for r/R=0. 99 region for CX+RS measurement (right) With 30+20 ks observations, we can determine F/R ratio within 10% error. We can detect clearly CX and RS effect for the first time. ->Discoveries of new (to X-ray astronmy) emission processes from SNR plasmas. case 1 Recombining timescale (s cm-3) satellite line effect Case 3 satellite line effect Fig. 8. Upper panels show 100 ks simulation of Fe-K line region of W 49 B with for cases 1 and 3 in Fig. 7. Lower panels show the difference between these models and model 2. s < 0. 16 e. V We can distinguish the super-solar or several solar abundance for the first time ! Topic: Searching for Thermal Emission in the Synchrotron-Dominated PWNe With 100 ks observation, we can detect significant residual on Fe-K satellite line. -> Precise measurement of relaxation time and initial k. T. First clue how the shock exchange thermal energy with interstellar medium. Topic: Determination of Cooling Process by Mori, Safi-Harb The nature of the supernova explosion and progenitor of "naked" (shell-less) Crab-like PWN is still a mystery. There is however accumulating evidence for weak thermal X-ray emission from their extended emission. -> SXS will resolve emission lines from thermal plasma and help measure the abundances from so-far-hidden ejecta. by Sawada, Minami, Yamauchi Cooling process: rarefaction or conduction? rarefaction … high density, high k. T CIE -> cooling by adiabatic expansion k. T should follow electron k. T conduction … before cooling ion k. T >> electron k. T electron cooled down faster ion k. T >> electron k. T -> thermal broadening ! Fig. 9. Same 100 ks simulation but with thermal broadening in case 2. We assumed k. Ti=10 k. Te. Best Target: 3 C 58 thermal broadening effect ! Extended enough to avoid the central pulsar. Clue of thermal emission (southwest region; Gotthelf+07). Simulation result: A 100 ks observation will enable us to determine the line ratio; Ne/O: 1. 2 +/- 0. 2 Fe/O: 0. 7+/- 0. 1 -> First measurement of O/Ne/Fe ratio of PSR dominant SNRs. Crucial information of the progenitor. Further impacts Ø We can constrain turbulence velocity in SNRs for the first time with the escape probability (colored region in Fig. 2). <- crucial physical parameter for CR acceleration in SNR shocks, mixing w. ISM, etc. …. Ø Conventional study shows that many old SNRs have ~0. 2 solar abundance, which is much lower than ISM, which is a major problem in understanding chemical evolution of our universe. With Astro-H observations, the abundance will be measured correctly and solve this problem. case 2 Case 1 SXS FOV Fig. 5. 100 ks simulation results r/R=0. 99 W/o RS/CX W/ RS+CX Fig. 7. Contour map of Fe-K H/He line ratio. Suzaku constrained region for W 49 B is shown in the dashed line. We cannot resolve the time scale or initial temperature. Simulation result 0. 9 r/R=0. 95 W/o RS W/ RS case 3 Several solar case (10 solar) -> expected k. Ti = 0. 3 ke. V s=0. 45+/-0. 15 e. V Fig. 2. Escape probability of O He-alpha resonance line One of the Suzaku great discoveries was the detection of recombining plasmas (Yamaguchi+09, Ozawa+09, Ohnishi+11, Sawada+12, …). However, basic information about the process is unknown, including whether initial temperature is high or low, and the relaxation time is long or short, since CCDs can resolve only H-like and H-like lines. Bright SNR with recombining plasma and strong Fe-K line. We assumed uniform distribution of Fe-K line in the SNR. zoom up 0. 8 by Sawada, Minami, Yamauchi Best Target: W 49 B Fig. 4. XMM image of Vela Shrapnel D. Simulation results Key 3: Understanding the cooling process SNRs disappear by mixing with ISM. Examining how plasmas cool in SNRs cool is crucial for understanding how thermal energy is distributed into the ISM. Initial temperature(ke. V) Key 1: New emission process of plasma Recent studies show clues of new emission processes in thermal plasmas. Studies are needed both to explore the fundental phyiscs of these prcesses as well as the development of shocks in SNRs. Key 2: Heavy elements buried in ISM and PWN It is unknown how much heavy elements are injected from each SNRs, although it is a key parameter of chemical evolution of our universe. Many old SNRs show sub-solar abundances, suggesting the ISM is sub-solar, and this is a mystery that needs to be understood. Fig. 6. Left: XMM 3 C 58 image with possible SXS FOVs. Yellow one is the best candidate. Right: 100 ks simulation of SW region of 3 C 58. The contamination of the pulsar is estimated by simx. We can resolve the cooling process for the first time. The first information how SNRs disappear into the ISM. References Aschenbach, B. et al. 1995, Nature, 373, 587 Gotthelf, E. V. et al. 2007, Ap. J, 654, 267 Katsuda, S. et al. 2005, PASJ, 57, 621 Katsuda, S. et al. 2011, Ap. J, 730, 24 Miyata, E. et al. 2008, PASJ, 60, 521 Ohnishi, T. et al. 2011, PASJ, 63, 527 Ozawa, M. et al. 2009, Ap. JL, 706, 71 Sawada, M. et al. 2012, PASJ, 64, 81 Yamaguchi, H. et al. 2009, Ap. JL, 705, 6