京都大学 · 物理学・天文学
Shoji Ogawa教授の研究室は、銀河中心の超大質量ブラックホールが活性化する活動銀河核(AGN)のX線・赤外線スペクトルを、クラッピーアダプター(clumpy torus)モデルを用いて精密に解析する研究を展開しています。特に、XCLUMPYモデルを用いた広帯域X線スペクトル解析により、AGNの遮蔽構造やエネルギー放出メカニズムの解明を進めています。近年では、XRISMやNuSTARなどの最新X線望遠鏡を活用した高分解能スペクトル観測も実施しており、ブラックホール周辺のガスの物理状態を解明する国際共同研究が中心です。
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Abstract We present the results of a systematic, broadband X-ray spectral analysis of nearby active galactic nuclei (AGNs) with the X-ray clumpy torus model (XCLUMPY). By adding 16 AGNs newly analyzed in this paper, we study a total of 28 AGNs, including unabsorbed and absorbed AGNs taken from Ichikawa et al. and García-Bernete et al. This is the largest sample whose X-ray and infrared spectra are analyzed by the clumpy torus models XCLUMPY and CLUMPY, respectively. The relation between the Eddi
Abstract We apply a new X-ray clumpy torus model, XCLUMPY, in which the clump distribution is assumed to be the same as that in the infrared clumpy torus model (CLUMPY) by Nenkova et al., to the broadband X-ray spectra of type-1 active galactic nuclei (AGNs) for the first time. We analyze the archival data of IC 4329A and NGC 7469 observed with NuSTAR / Suzaku and NuSTAR / XMM-Newton , respectively, whose infrared spectra were studied with CLUMPY by Ichikawa et al. and optical extinctions ( A V
Abstract To investigate the origins of the warm absorbers in active galactic nuclei (AGNs), we study the ionization-state structure of the radiation-driven fountain model in a low-mass AGN and calculate the predicted X-ray spectra utilizing the spectral synthesis code Cloudy . The spectra show many absorption and emission line features originating in the outflowing ionized gas. The O viii 0.654 keV lines are produced mainly in the polar region much closer to the supermassive black hole than the
Abstract We present the first high-resolution X-ray spectrum of NGC 7213 obtained with XRISM/Resolve, supported by simultaneous XMM-Newton, NuSTAR, and SOAR optical data. The XRISM spectrum resolves the neutral Fe K α into two components: a narrow core ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi mathvariant="normal">FWHM</mml:mi> <mml:mo>=</mml:mo> <mml:mn>65</mml:mn> <mml:msubsup> <mml:mrow> <mml:mn>0</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <
The Kyoto University Digital Library makes images of the rare materials that it holds available to general public. While most of the pages consist of scanned images alone, some are accompanied by corresponding encoded text data. This report summarizes the principal parts of the procedures for producing image data. Demand for a well-designed interface grows as the amount of available digital data expands, as the Internet environment develops with easier access to digital contents and as high-qual
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