Diagnostics of thermal plasma with eV-level Resolution

1. Diagnostics of thermal plasma with eV-level Resolution Manabu ISHIDA Tokyo Metropolitan University

2. 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/XMM-Newton. • Te TioniTZ AZne 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.

3. Iron spectrum at Tmax of He-like K • He-like • resonance (r) • w :1P1 → 1S0 • intercombination (i) • x :3P2 → 1S0 • y :3P1 → 1S0 • forbidden (f) • z :3S1 → 1S0 • H-like • resonance • Ly1 :2P1/2→2S1/2 • Ly2 :2P3/2→2S1/2 B

4. Density diagnostics with He-like triplet Ishida (1995) Porquet et al (2001) • 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. r i f

5. CVs T Tau star Solar corona Stellar flare He-like triplet as a density probe nc(Z) = 6.75 (Z-1)11.44 cm-3 Proto star Tm(Z) = 8320 (Z-0.4)2.71 K

6. Density measurement of AE Aqr with XMM RGS • AE Aqr (mCV, Pspin = 33.08s, Porb = 9.88h, B = 105-6G ?) • ne~1011cm-3, lp = (2-3)x1010cm Itoh et al. (2006)

7. 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.

8. AE Aqr as a Magnetic Propeller Source • Steady spin down (P-dot = 5.64x10-14 s s-1) for >14 yrs. • TeV g-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. Wynn & King (1997)

9. Origin of the GRXE Suzaku XIS 6.4keV • Thin thermal: kTmax ~ 7keV. • Diffuse ? • Ebisawa et al. (2005) • 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. Thanks to S. Yamauchi@Iwate B

10. 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.

11. Origin of the Satellite Lines 0 E • Satellite lines of Z+z originates from ion Z+(z1). • Spectatorshields part of the charge of the nuclei. • Er > ES4 > ES3 > ES2 • ES2is 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 He-like ion. • IE: additionally with Li-like ion.

12. Spectrum of H-like/He-likeiron 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

13. 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.

14. Intensity of the satellites with Te kTe = 1.6keV kTe = 3.2keV kTe = 7.9keV

15. SNR: NEI with kTe = 2keV

16. 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 • j/w is stronger, (q+t)/w is weaker thanthat of CIE plasma. • Central region of the cluster of galaxies, stellar flare, post-shock accregion flow in mCV… B

17. 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…

18. 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