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6.4 keV (Neutral Fe)

X-ray or Electron irradiation ?. (1) Diffuse ? or Integrated point sources ?. GC. Spatial Distribution of the Galactic Diffuse X-Rays and Time Variability of the 6.4-keV Clumps Katsuji Koyama Kyoto University. 2.5 keV (He-like S). 6.7 keV (He-like Fe). 6.4 keV (Neutral Fe).

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6.4 keV (Neutral Fe)

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  1. X-ray or • Electron • irradiation ? (1) Diffuse ? or Integrated point sources ? GC Spatial Distribution of the Galactic Diffuse X-Rays and Time Variability of the 6.4-keV Clumps Katsuji Koyama Kyoto University 2.5 keV (He-like S) 6.7 keV (He-like Fe) 6.4 keV (Neutral Fe)

  2. Sgr A* Sgr A* The 6.7 keV line flux vs Integrated point source flux (Chandra deep exposure) NearGC ( |I| < 0.3 deg) l-distribution b-distribution 10 x 6.7 keV line (EW=0.5 keV) Point source Flux (4.8-8 keV) ( ｂ)

  3. The 6.7 and 6.96 keV lines in GC andGR 6.7 keV line : Exponential FWHM ~ 0.2 deg 6.7keV lines Point-sources: power-law index = 0.9 (Infrared star numbers, Chandra point sources) 6.96/6.7 keV Temperature F6.96/F6.7 ~0.3 --0.4 (GC) ~ 0.2--0.3(GR)

  4. Gamma is constant (~1.9) (independent of F6.4/F6.7) Made 2 x 16 spectra and fit with a model of Power-law + Gaussian lines Gamma, Fluxes (F) and Equivalent width (EW) Gamma:Power-law Index F5-10 : 5-10 keV band F6.4 , EW6.4 : 6.4 keV line F6.7 , EW6.7 : 6.7 keV line F6.4/F6.7 vs Gamma Gamma F6.4/F6.7

  5. EW6.7+0.5EW6.4 = Constant 100F6.7 10F6.4 Phenomenologically, about 2/3 (1/1.5) of the 5-10 keV flux is associated to the 6.7 keV line and the other 1/3 (0.5/1.5) is associated to the 6.4 keV line. Koyama te al. 2008 F6.7 + 0.5F6.4 F5-10

  6. 2 x 1.9 + 0.9 ~ 3x 1.4 4 x 1.9 - 0.9 ~3x 2.4 6.7 keV “Territory” 6.4 keV “Territory” Muno et al. 2004 Koyama et al. 2008

  7. The 6.4 keV Clump EW=1.8 keV EW=1.8 keV M 359.43 M 359.47

  8. Sgr A* Sgr A* 6.4 keV Line is time variable. (Muno et al. 2007) A Clump near the Radio Arc Chandra (2002) Suzaku (2005) Chandra (2002) Suzaku (2005) ---------------------------------------------------------------------------- 6.4 keV line 7.83-0.14+0.14 6.89-0.14+0.12 * ---------------------------------------------------------------------------- (10-5 photons s-1cm-2) *4.7 sigma variability (1.5 sigma for the 6.7 keV line)

  9. ~10pc The Sgr B2 Cloud Variability time scale of the 6.4 keV flux ~5 - 10 ys (Inui et al. 2008) M 0.66 G 0.570 This flux change can not be explained by electrons. We need X-ray irradiation. Where is the X-ray source ?

  10. 1994年 X-ray front 2000年 2005年 2004年

  11. If the X-ray front has a narrow width ~10 ly, then X-ray reflection zone is parabola, where the origin of the coordinate is Sgr A* Sgr A* 2ay=x2 - a2: a = 300 light-years

  12. ＊ Sawada et al. 2004

  13. Conclusions • Integrated flux of point sources • contributes ~1/6 of the total Galactic • center X-rays (GCX). • (2) Major fraction of the GCX is diffuse . • (3) Plasma temperature of the GC • is probably higher than that of the GR. • (4) 6.4 keV line clumps are time variable, • hence the most probable origin is X-ray • reflection.

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