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The stellar distribution derived from an $H$ and $K_{mathrm S}$-band survey of the central region of our Galaxy is compared with the Fe XXV K$alpha$ (6.7 keV) line intensity observed with the Suzaku satellite. The survey is for the Galactic coordinates $|l| lesssim 3^{circ}.0$ and $|b| lesssim 1^{circ}.0$ (equivalent to 0.8 kpc $times$ 0.3 kpc for $R_0 = 8$ kpc), and the number-density distribution $N(K_{mathrm S,0}; l, b)$ of stars is derived using the extinction-corrected magnitude $K_{mathrm S,0}=10.5$. This is deep enough to probe the old red giant population and in turn to estimate the ($l$, $b$) distribution of faint X-ray point sources such as coronally active binaries and cataclysmic variables. In the Galactic plane ($b=0^{circ}$), $N(10.5; l, b)$ increases to the Galactic center as $|l|^{-0.30 pm 0.03}$ in the range of $-0^{circ}.1 geq l geq -0^{circ}.7$, but this increase is significantly slower than the increase ($|l|^{-0.44 pm 0.02}$ ) of the Fe XXV K$alpha$ line intensity. If normalized with the ratios in the outer region $1^{circ}.5 leq |l| leq 2^{circ}.8$, where faint X-ray point sources are argued to dominate the diffuse Galactic X-ray ridge emission, the excess of the Fe XXV K$alpha$ line intensity over the stellar number density is at least a factor of two at $|l| = 0^{circ}.1$. This indicates that a significant part of the Galactic center diffuse emission arises from a truly diffuse optically-thin thermal plasma, and not from an unresolved collection of faint X-ray point sources related to the old stellar population.
An elongated X-ray source with a strong K-shell line from He-like iron (Fe XXVI) is found at (RA, Dec)_{J2000.0}=(17h44m00s.0, -29D1340.9) in the Galactic center region. The position coincides with the X-ray thread, G359.55+0.16, which is aligned wit
We analyse the 6.4 keV iron line component produced in the Galactic Center (GC) region by cosmic rays in dense molecular clouds (MCs) and in the diffuse molecular gas. We showed that this component, in principle, can be seen in several years in the d
There are a number of faint compact infrared excess sources in the central stellar cluster of the Milky Way. Their nature and origin is unclear. In addition to several isolated objects of this kind we find a small but dense cluster of co-moving sourc
The dark matter spike induced by the adiabatic growth of a massive black hole in a cuspy environment, may explain the thermal dark matter density required to fit the cut-off in the HESSJ1745-290 gamma-ray spectra as TeV dark matter signal with a back
We present a NIR polarimetric map of the 1deg by 1deg region toward the Galactic center. Comparing Stokes parameters between highly reddened stars and less reddened ones, we have obtained a polarization originating from magnetically aligned dust grai