1. The Galactic Center region The Galactic Center region K. Koyama and A. Senda (Kyoto-U) Y. Maeda and H. Murakami (ISAS / JAXA) Y. Maeda and H. Murakami (ISAS / JAXA)

2. The central region of our galaxy Various high energy activities Various high energy activities The nearest MBH (= Sgr A*) The nearest MBH (= Sgr A*) Largely extended hot plasma Largely extended hot plasma ⇒ 10 5 yrs past activity of the GC ⇒ 10 5 yrs past activity of the GC SNR / SNR candidates SNR / SNR candidates ⇒ 10 4 yrs past activity of GC ⇒ 10 4 yrs past activity of GC X-ray reflection nebulae X-ray reflection nebulae ⇒ 10 3 yrs past activity of GC ⇒ 10 3 yrs past activity of GC

3. Target selection Target selection The GC hot plasma The GC hot plasma plasma dynamics, galactic rotation plasma dynamics, galactic rotation Sgr A East Sgr A East SNR dynamics, galactic rotation SNR dynamics, galactic rotation Sgr B2 / Radio arc Sgr B2 / Radio arc X-ray reflection nebula, Compton shoulder / recoil X-ray reflection nebula, Compton shoulder / recoil

4. GC hot plasma Neutral Iron (6.4 keV) Neutral Iron (6.4 keV) Trace the dynamics of the Trace the dynamics of the Cold Molecular cloud He/H-like Fe-K (6.7 / 6.9 keV) He/H-like Fe-K (6.7 / 6.9 keV) Trace the dynamics of the hot plasma Trace the dynamics of the hot plasma Molecular cloud motion maybe Dominated by Galactic Rotation Dominated by Galactic Rotation ⇒ What regulates the plasma dynamics ? Galactic Rotation ? Galactic Rotation ? Thermal motion ? Thermal motion ? Past explosive event of Sgr A* ? Past explosive event of Sgr A* ? ⇒ What is the relation between the dynamics of cold and hot matter ? the dynamics of cold and hot matter ? Sgr A* Rotation curve near the GC region Sgr A East GC hot Plasma

5. Plasma motion On the galactic rotation curve On the galactic rotation curve ⇒ V rot ～ 20 km/s @10 pc ⇒ V rot ～ 20 km/s @10 pc ⇒ ΔE ～ 0.4 eV ⇒ ΔE ～ 0.4 eV Thermal motion Thermal motion ⇒ V th ～ 170 km/s @10keV ⇒ V th ～ 170 km/s @10keV ⇒ σ ～ 4 eV ⇒ σ ～ 4 eV Expanding motion centered at Sgr A* Expanding motion centered at Sgr A* XRS 100 ks simulation XRS 100 ks simulation @6.7 keV resonance line @6.7 keV resonance line ΔE = ±0.5 eV ΔE = ±0.5 eV Δσ= ±0.3 eV Δσ= ±0.3 eV Galactic rotation is detectable.

6. Sgr A East Chandra confirmed Sgr A Chandra confirmed Sgr A East is an SNR (Maeda et al. 2002). East is an SNR (Maeda et al. 2002). Mixed-Morphology SNR Mixed-Morphology SNR High temperature High temperature (2 keV or 1 + 4keV) (2 keV or 1 + 4keV) High metal abundances (> 3solar) High metal abundances (> 3solar) Regulate the past activity of Sgr A* ? Regulate the past activity of Sgr A* ? Key science Temperature measurement Temperature measurement line ratio 6.9/6.7 line ratio 6.9/6.7 SNR dynamics SNR dynamics Whether on the Galactic rotation curve? Whether on the Galactic rotation curve? Chandra ACIS-I Sgr A*

7. Simulated spectrum XRS 100 ks simulation GC hot plasma component is excluded Si / S / Ar / Fe line Fine structures around 6.7 keV line can be resolved resonance intercombinations forbidden Li/Be-like satellites line center error ～ ±0.3 eV line width error ～ ±0.4 eV 6.4-6.8 keV ～ 20 km/s galactic rotation are detectable

8. Sgr B2 / Radio arc Giant Morecular clouds Irradiated by The External source toward the GC. Giant Morecular clouds Irradiated by The External source toward the GC. ⇒ X-ray reflection nebulae (XRN) ⇒ X-ray reflection nebulae (XRN) Key Science Compton shoulder of 6.4 keV fluorescent Compton shoulder of 6.4 keV fluorescent ⇒ Prove Geometry of the Irradiation source ⇒ Prove Geometry of the Irradiation source Compton recoil of strong 6.7 keV Compton recoil of strong 6.7 keV irradiation irradiation ⇒ Prove 3D configuration of Molecular cloud and Irradiating ⇒ Prove 3D configuration of Molecular cloud and Irradiating Source (Sgr A*). Source (Sgr A*). Confirm the XRN model and Trace the past activity of Sgr A* x10 38 (year) Past luminosities of Sgr A * 3’

9. Sgr B2 XRS 100 ks simulation Compton shoulder of 6.4 keV is clearly seen. Compton shoulder of 6.4 keV is clearly seen. 6.4 keV neutral Kα 6.4 keV neutral Kα Line center ±0.3 eV Line center ±0.3 eV Width 1.68 eV(1.32 – 1.95) Width 1.68 eV(1.32 – 1.95) Compton shoulder Compton shoulder Energy uncetainity ～ 10 eV Energy uncetainity ～ 10 eV Intensity ～ 20-30 % Intensity ～ 20-30 % ⇒ Irradiated direction are determined within 10 % 6-7.5 keV 6.37 keV Kα Kβ Absorption edge

10. Radio arc Reflection (PL + 6.4 keV fluorescent) + Reflection (PL + 6.4 keV fluorescent) + Thermal component Thermal component 6.4 keV ⇒ molecular cloud geometry geometry 6.7 keV ⇒ plasma dynamics 100 ks XRS observation 100 ks XRS observation center width center width 6.4 keV ±0.3 eV ±0.5 eV 6.7 keV ±1.2 eV ±1.5 eV 6-7.5 keV

11. Non-thermal emission Connection between 10keV --sub MeV band High energy activity at the GC. Integral IBIS/ISGRI 20-40keV 2deg x 2deg image of GC