Presentation on theme: "Thermal X-ray in SNR Patrick Slane Zhang Ningxiao."— Presentation transcript:
Thermal X-ray in SNR Patrick Slane Zhang Ningxiao
three regions fast shocks in SNR heat matter to millions of degrees 1.behind the forward shock, ISM heat by forward shock 2.interior to the SNR, cold eject heat by reverse shock 3.outside PWN, eject heat by expand nebular
The components inside the SNR synchroton non-thermalthermal radiation mechanism synchrotronejectashocked gas reflected shockforward shock modelpowerlawvnei (hard to fit) vneiapec noteP index is 2.5lots of emission lines really high temperature & low τ low temperature
electron temperature lower than the ion (low mass) the detected temperature is lower than estimate. 1) slow temperature equilibration 2) cosmic-ray acceleration In some case, high Te/Tp provide equilibration. Electron heated by lower hybrid waves. (Balmer lines, high-res spectra)
τ The plasma reaches collisional ionization equilibrium forτ>=10^12.5 cm^-3 s; if τ is lower than this, means nonequilibrium ionization.
The Chandra observation of 1E , show a smaller radius of OVII than OVIII. And this indicates reverse shock heated the eject. The same thing in G for forward shock.
overionized In some case, the ionization temperature is higher than Te indicates an overionized plasma.(W49B) rapid expansion and adiabatic cooling have lowered the plasma temperature to a value below its ioniztion state.
Ejecta define the type of SNRs. Type Ia dominated by Fe, Type II contain much larger amounts of O When the SNR is young the thermal X-ray spectra provide rich information of ejecta.
Example Kepler's SNR Type Ia (dominate Si, S, Fe) Based on this CC always asymmetric 1) the environments 2) itself
Shocked Circumstellar Material RSG or WR wind episodes is expected to show the signatures of CNO cycle, leads to an environment with enhanced N/O ratio. so study the X-ray behind the FS can lead us know late-phase properties of the progenitor star. (type, age, mass...)
Example G RGS spectra shows overabundance of N and an underabundace of O, this indicate a result of CC event from a fairly massive progenitor.
Particle Acceleration(?) Much of this evidence is provided by synchorotron radiation significant information is provided by thermal X-ray emission as well. (1E ) The temperature of X-ray is much lower than indicate from shock velocity. --> more energy accelerate particles instead of heating the gas. (Tycho,FS and RS small) need a factor of 100!!!