132 research outputs found
99mTc-HMPAO標識白血球シンチグラフィにて骨髄転移を認めた悪性リンパ腫の1例
富山医科薬科大学 放射線原著論文/症例報
The Suzaku Observation of the Nucleus of the Radio-Loud Active Galaxy Centaurus A: Constraints on Abundances of the Accreting Material
A Suzaku observation of the nucleus of the radio-loud AGN Centaurus A in 2005
has yielded a broadband spectrum spanning 0.3 to 250 keV. The net exposure
times after screening were: 70 ks per X-ray Imaging Spectrometer (XIS) camera,
60.8 ks for the Hard X-ray Detector (HXD) PIN, and 17.1 ks for the HXD-GSO. The
hard X-rays are fit by two power-laws of the same slope, absorbed by columns of
1.5 and 7 * 10^{23} cm^{-2} respectively. The spectrum is consistent with
previous suggestions that the power-law components are X-ray emission from the
sub-pc VLBI jet and from Bondi accretion at the core, but it is also consistent
with a partial covering interpretation. The soft band is dominated by thermal
emission from the diffuse plasma and is fit well by a two-temperature VAPEC
model, plus a third power-law component to account for scattered nuclear
emission, jet emission, and emission from X-ray Binaries and other point
sources. Narrow fluorescent emission lines from Fe, Si, S, Ar, Ca and Ni are
detected. The Fe K alpha line width yields a 200 light-day lower limit on the
distance from the black hole to the line-emitting gas. Fe, Ca, and S K-shell
absorption edges are detected. Elemental abundances are constrained via
absorption edge depths and strengths of the fluorescent and diffuse plasma
emission lines. The high metallicity ([Fe/H]=+0.1) of the circumnuclear
material suggests that it could not have originated in the relatively
metal-poor outer halo unless enrichment by local star formation has occurred.
Relative abundances are consistent with enrichment from Type II and Ia
supernovae.Comment: Accepted for publication to ApJ. 22 pages, 11 figures (3 color). Uses
emulateapj5.sty. Grammatical errors corrected; some references update
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