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Diagnostics of thermal plasma with eV-level Resolution Manabu ISHIDA Tokyo Metropolitan University 1 Objectives of Plasma Diagnostic (with NeXT in particular) ■ Measurements of physical parameters of thermal plasma. kT ~ keV For better understanding of star-forming region, star, planetary nebula, supernova remnant, binary, galaxy, cluster of galaxies… He(H)-like K of iron in general, of other metals from diffuse source which are inaccessible with Chandra/XMMNewton. Te Tioni TZ AZ ne etc… Bulk motion of plasma in particle-acceleration regions. Geometry of the plasma surrounding a compact object. Turbulence in the clusters of galaxies Shock front of SNR. Help understanding non-thermal universe in E > 10 keV. 2 Iron spectrum at Tmax of He-like K • He-like • resonance (r) w : 1P1 → 1S0 • intercombination (i) x : 3P2 → 1S0 y : 3P1 → 1S0 • H-like • resonance Ly1 : 2P1/2 → 2S1/2 Ly2 : 2P3/2 → 2S1/2 • forbidden (f) z : 3S1 → 1S0 B 3 Density diagnostics with He-like triplet Ishida (1995) Porquet et al (2001) r i f • 3S1 decays through 3P2,1 if A(3S1-1S0) ~ neC(3S1-3P2,1) • f + i = const. • Caution: 3S1 →3P2,1 occurs also with UV photo-excitation. • Resolving degeneracy between ne and V in a point source. 4 nc(Z) = 6.75 (Z-1)11.44 cm-3 He-like triplet as a density probe CVs T Tau star Solar coronaStellar flare Proto star Tm(Z) = 8320 (Z-0.4)2.71 K 5 Density measurement of AE Aqr with XMM RGS Itoh et al. (2006) • AE Aqr (mCV, Pspin = 33.08s, Porb = 9.88h, B = 105-6G ?) • ne~1011cm-3, lp = (2-3)x1010cm 6 What’s happening in AE Aqr ?! • In the accretion column of mCV ne~1016cm-3, lp ~107cm, whereas ne~1011cm-3, lp = (2-3)x1010cm. kT (~ GMmH/R) of AE Aqr is extremely lower than other mCVs, suggestive of intermediate release of the gravitational energy. Plasma is surely accreting because we have X-ray emission, but not arriving at the white dwarf surface, diffuse in an orbit scale. 7 AE Aqr as a Magnetic Propeller Source Wynn & King (1997) • Steady spin down (P-dot = 5.64x10-14 s s-1) for >14 yrs. • TeV -ray emission. • Note: no bulk velocity is detected from oxygen K. v < 300 km s-1 (expected ~100km s-1). • The maximum vbulk is expected iron K. Theme of the calorimeter onboard NeXT. 8 Origin of the GRXE • Thin thermal: kTmax ~ 7keV. • Diffuse ? Ebisawa et al. (2005) Suzaku XIS 6.4keV • Ensemble of point sources ? Revnivtsev et al. (2006) CVs or Active Star Binaries. • Suzaku clearly detected 6.4keV line from the GRXE. ASB CV • Suzaku should measure spatial uniformity of intensity ratios of the iron K components. • Debate will be terminated if ne is measured with the NeXT calorimeter. B Thanks to S. Yamauchi@Iwate 9 He-like Satellite lines • Satellite lines: a series of mission lines at energies slightly lower than w. • More intense for larger Z, prominent for iron. New information that can be accessed first by the NeXT calorimeter. 10 Origin of the Satellite Lines • Satellite lines of Z+z originates from ion Z+(z1). • Spectator shields part of the charge of the nuclei. Er > ES4 > ES3 > ES2 • ES2 is strongest and most separated from w. • Sn (n≧4) cannot be separated from r. • Satellite of H-like K originates from DR. • Satellite of He-like K 1s2[sp]2p→(1s)22p: DR 1s2[sp]2s→(1s)22s : DR+IE DR: interaction of e- with Helike ion. IE: additionally with Li-like ion. 11 Spectrum of H-like/He-like iron K ◆Number of major satellite lines with spectator n=2 is 22. Spectator = 2p (DR): a, b, c, …, m, n: 14 in total. j and k are prominent Spectator = 2s (DR+IE): o, p, q, …, u, v: 8 in total. r, q, and t are strong in ionizing plasma 12 Te with G = (x+y+z)/w vs j+k/w w, j, k: all originate from interaction between an electron and a He-like ion. Their intensity ratio is a function only of Te. It does not matter even if NEI. The intensity ratio does not depend on ne. It has been claimed that G = (x+y+z)/w is a good measure of Te, however …. j+k/w is much more sensitive to Te. 13 Intensity of the satellites with Te kTe = 1.6keV kTe = 3.2keV kTe = 7.9keV 14 SNR: NEI with kTe = 2keV 15 Te from j/w, Tioni from (q+t)/w • For SNR: j/w: Te, (q+t)/w: net, line width: TZ, central energy: vbulk. • For recombining plasma B j/w is stronger, (q+t)/w is weaker than that of CIE plasma. Central region of the cluster of galaxies, stellar flare, post-shock accregion flow in mCV… 16 Boundary Layer of Dwarf Novae Accretion onto WD takes place through an optically thick Keplerian disc (T~105K). Hard X-rays are radiated from the Boundary Layer which is optically thin/geometrically thick with T~108K. The rotation speed of WD at its surface is usually much smaller than vK(R*) (~5000km/s). For settling down onto the white dwarf, accreting matter is decelerated from vK to v* by converting its Keplerian kinetic energy into heat. Understanding of BL is not yet enough on various aspects such as size, density, geometry (2-dim or 3-dim) etc… 17 SS Cyg with Chandra HETG • Lines are broad in Outburst. • If BL is like a cooling flow, the line originates in a radially falling spherical shell. Line profile becomes rectangular rather than a simple broad Gaussian. • Need info of iron to discriminate in/out flow. We need NeXT calorimeter. Okada et al. (2006) B 18