Yuichi Terashima

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High-sensitivity wide-band X-ray spectroscopy is the key feature of the Suzaku X-ray observatory, launched on 2005 July 10. This paper summarizes the spacecraft, in-orbit performance, operations, and data processing that are related to observations. The scientific instruments, the high-throughput X-ray telescopes, X-ray CCD cameras, non-imaging hard X-ray(More)
We report the detection of a 5.8 × 10 s periodicity in the 0.5–10 keV X-ray light curve of the Seyfert galaxy IRAS18325–5926, obtained from a 5-day ASCA observation. Nearly 9 cycles of the periodic variation are seen; it shows no strong energy dependence and has an amplitude of about 15 per cent. Unlike most other well-studied Seyfert galaxies, there is no(More)
This paper presents a comprehensive study of the X-ray properties of low-ionization nuclear emission-line regions (LINERs) and low-luminosity Seyfert galaxies based on observations obtained with the ASCA satellite. We analyzed data of 53 observations of 21 LINERs and 17 low-luminosity Seyferts. X-ray emission has been detected in all but one object. The(More)
Suzaku has, for the first time, enabled the hard X-ray variability of the Seyfert 1 galaxy MCG–6-30-15 to be measured. The variability in the 14–45 keV band, which is dominated by a strong reflection hump, is quenched relative to that at a few keV. This directly demonstrates that the whole reflection spectrum is much less variable than the power-law(More)
We present a comparison between the 2001 XMM–Newton and 2005 Suzaku observations of the quasar, PG 1211+143, at z = 0.0809. Variability is observed in the 7 keV iron K-shell absorption line (at 7.6 keV in the quasar frame), which is significantly weaker in 2005 than during the 2001 XMM–Newton observation. From a recombination time-scale of <4 yr, this(More)
We present the Suzaku broad band observations of two AGNs detected by the Swift/BAT hard X-ray (>15 keV) survey that did not have previous X-ray data, Swift J0601.9–8636 and Swift J0138.6–4001. The Suzaku spectra reveals in both objects a heavily absorbed power law component with a column density of NH ≃ 1023.5−24cm−2 that dominates above 10 keV, and an(More)
We report on a 100 ks Suzaku observation of the bright, nearby (z = 0.008486) Seyfert 1.9 galaxy MCG -5-23-16. The broad-band (0.4–100keV) X-ray spectrum allows us to determine the nature of the high energy emission with little ambiguity. The X-ray continuum consists of a cutoff power-law of photon index Γ = 1.9, absorbed through Compton-thin matter of(More)
We report Chandra ACIS and quasi-simultaneous RXTE observations of the nearby, powerful radio galaxy Cygnus A, with the present paper focusing on the properties of the active nucleus. In the Chandra observation, the hard (> a few keV) X-ray emission is spatially unresolved with a size ∼< 1 (1.5 kpc, H0 = 50 km s Mpc) and coincides with the radio and near(More)
The globular cluster M15 has recently been found to host a possible central black hole with a mass of ∼2000 M⊙. A deep, high-resolution Chandra image failed to detect the “nucleus” of the cluster in X-rays. The upper limit on the X-ray luminosity (Lx ∼< 5.6×10 32 erg s−1) corresponds to a bolometric Eddington ratio of Lbol/LEdd ∼ < (2 − 4)×10−8. Combining(More)
Broad line radio galaxies (BLRGs) are a rare type of radio-loud AGN, in which the broad optical permitted emission lines have been detected in addition to the extended jet emission. Here we report on deep (40ksec ×4) observations of the bright BLRG 3C 120 using Suzaku. The observations were spaced a week apart, and sample a range of continuum fluxes. An(More)