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. He(H)-like K  T e T ioni T Z A Z n e etc… T e T ioni n e ■ Bulk motion of plasma in particle-acceleration regions.  Geometry of the plasma surrounding a compact object. Geometry  Turbulence in the clusters of galaxies Shock front of SNR.  Help understanding non-thermal universe in E > 10 keV.

3 Iron spectrum at T max of He-like K  He-like resonance ( r )  w : 1 P 1 → 1 S 0 intercombination ( i )  x : 3 P 2 → 1 S 0  y : 3 P 1 → 1 S 0 forbidden ( f )  z : 3 S 1 → 1 S 0 H-like resonance  Ly  1 : 2 P 1/2 → 2 S 1/2  Ly  2 : 2 P 3/2 → 2 S 1/2 B

4 Density diagnostics with He-like triplet 3 S 1 decays through 3 P 2,1 if A( 3 S S 0 ) ~ n e C( 3 S P 2,1 ) f + i = const. Caution: 3 S 1 → 3 P 2,1 occurs also with UV photo-excitation. Resolving degeneracy between n e and V in a point source. Porquet et al (2001) Ishida (1995) r i f

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

6 Density measurement of AE Aqr with XMM RGS AE Aqr (mCV, P spin = 33.08s, P orb = 9.88h, B = G ?) n e ~10 11 cm -3, p = (2-3)x10 10 cm Itoh et al. (2006)

7 What’s happening in AE Aqr ?! In the accretion column of mCV  n e ~10 16 cm -3, p ~10 7 cm, whereas n e ~10 11 cm -3, p = (2-3)x10 10 cm.  kT (~ GMm H /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 = 5.64x 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 v bulk is expected iron K .  Theme of the calorimeter onboard NeXT. Wynn & King (1997)

9 Origin of the GRXE Thin thermal: kT max ~ 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 n e is measured with the NeXT calorimeter. Suzaku XIS 6.4keV Thanks to S. 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 Satellite lines of Z +z originates from ion Z +(z  1). Spectator shields part of the charge of the nuclei.  E r > E S4 > E S3 > E S2 E S2 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) 2 2p: DR 1s2[sp]2s → (1s) 2 2s : DR+IE  DR: interaction of e - with He- like ion.  IE: additionally with Li-like ion. 0 E

12 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

13 T e 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 T e.  It does not matter even if NEI.  The intensity ratio does not depend on n e.  It has been claimed that G = (x+y+z)/w is a good measure of T e, however ….  j+k/w is much more sensitive to T e.

14 Intensity of the satellites with T e kT e = 1.6keV kT e = 3.2keV kT e = 7.9keV

15 SNR: NEI with kT e = 2keV

16 T e from j/w, T ioni from (q+t)/w For SNR: j/w : T e, (q+t)/w : n e t, line width: T Z, central energy: v bulk. For recombining plasma 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… B

17 Boundary Layer of Dwarf Novae  Accretion onto WD takes place through an optically thick Keplerian disc (T~10 5 K).  Hard X-rays are radiated from the Boundary Layer which is optically thin/geometrically thick with T~10 8 K. The rotation speed of WD at its surface is usually much smaller than v K (R * ) (~5000km/s). For settling down onto the white dwarf, accreting matter is decelerated from v K 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. B Okada et al. (2006)