| 1. |
- Morokuma, Tomoki, et al.
(author)
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OISTER optical and near-infrared monitoring observations of peculiar radio-loud active galactic nucleus SDSSJ110006.07+442144.3
- 2017
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In: Nippon Tenmon Gakkai obun kenkyu hokoku. - : Oxford University Press (OUP). - 0004-6264. ; 69:5
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Journal article (peer-reviewed)abstract
- We present monitoring campaign observations at optical and near-infrared (NIR) wavelengths for a radio-loud active galactic nucleus (AGN) at z = 0.840, SDSSJ110006.07+442144.3 (hereafter, J1100+4421), which was identified during a flare phase in late 2014 February. The campaigns consist of three intensive observing runs from the discovery to 2015 March, mostly within the scheme of the OISTER collaboration. Optical-NIR light curves and simultaneous spectral energy distributions (SEDs) are obtained. Our measurements show the strongest brightening in 2015 March. We found that the optical-NIR SEDs of J1100+4421 show an almost steady shape despite the large and rapid intranight variability. This constant SED shape is confirmed to extend to similar to 5 mu m in the observed frame using the archival WISE data. Given the lack of absorption lines and the steep power-law spectrum of alpha(upsilon) similar to -1.4, where f(v) proportional to v(alpha upsilon), synchrotron radiation by a relativistic jet with no or small contributions from the host galaxy and the accretion disk seemsmost plausible as an optical-NIR emission mechanism. The steep optical-NIR spectral shape and the large amplitude of variability are consistent with this object being a low.peak jet-dominated AGN. In addition, sub-arcsecond resolution optical imaging data taken with Subaru Hyper Suprime-Cam does not show a clear extended component and the spatial scales are significantly smaller than the large extensions detected at radio wavelengths. The optical spectrum of a possible faint companion galaxy does not show any emission lines at the same redshift, and hence a merging hypothesis for this AGN-related activity is not supported by our observations.
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| 2. |
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| 3. |
- Matsui, Satoshi, et al.
(author)
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All-optical modulation using intersubband transitions at 1.55 mu m in GaN/AlN multiple quantum well
- 2005
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In: Physica Status Solidi. C, Current topics in solid state physics. - : Wiley. - 1610-1634 .- 1610-1642. ; 2:7, s. 2748-2752
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Journal article (peer-reviewed)abstract
- All-optical modulation using intersubband transition (ISBT) resonant light (wavelength of 1.55 μm) and induced by UV interband transition (IBT) resonant light (325 nm or 213 nm) was demonstrated in a GaN/AlN multiple quantum well (MQW) waveguide device. The modulation was selective and occurred only for p-polarized ISBT resonant light in accordance with ISBT characteristics. An IBT relaxation time of 1.5 ns was obtained by fitting the experimental results with a three-level model, taking into consideration the valence band, the conduction band and the trap-state.
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| 4. |
- Tanaka, Masaomi, et al.
(author)
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DISCOVERY OF DRAMATIC OPTICAL VARIABILITY IN SDSS J1100+4421 : A PECULIAR RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXY?
- 2014
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In: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 793:2, s. L26-
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Journal article (peer-reviewed)abstract
- We present our discovery of dramatic variability in SDSS J1100+4421 by the high-cadence transient survey Kiso Supernova Survey. The source brightened in the optical by at least a factor of three within about half a day. Spectroscopic observations suggest that this object is likely a narrow-line Seyfert 1 galaxy (NLS1) at z = 0.840, however, with unusually strong narrow emission lines. The estimated black hole mass of similar to 10(7) M-circle dot implies bolometric nuclear luminosity close to the Eddington limit. SDSS J1100+4421 is also extremely radio-loud, with a radio loudness parameter of R similar or equal to 4 x 10(2)-3 x 10(3), which implies the presence of relativistic jets. Rapid and large-amplitude optical variability of the target, reminiscent of that found in a few radio- and gamma-ray-loud NLS1s, is therefore produced most likely in a blazar-like core. The 1.4 GHz radio image of the source shows an extended structure with a linear size of about 100 kpc. If SDSS J1100+4421 is a genuine NLS1, as suggested here, this radio structure would then be the largest ever discovered in this type of active galaxies.
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| 5. |
- Uchida, Hiroyuki, et al.
(author)
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Room-temperature operation of 1.55 um wavelength-range GaN/AlN quantum well intersubband photodetectors
- 2005
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In: IEICE Electronics Express. - : Institute of Electronics, Information and Communications Engineers (IEICE). - 1349-2543. ; 2:22, s. 566-571
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Journal article (peer-reviewed)abstract
- The room-temperature operation of a GaN/AlN quantum well infrared photodetector (QWIP) using the intersubband transition (ISBT) in a GaN/AlN multiple quantum well (MQW) was demonstrated for the first time. The GaN/AlN QWIP was operated under DC biasing with a vertically conductive geometry to the MQW layer. A clear photoinduced response was observed for P polarized 1.47µm light irradiation. Dependencies of the photoresponse on the applied DC bias voltage, and the polarization and wavelength of incident light were evaluated for the GaN/AlN QWIP. The maximum responsivity was estimated to be 0.11mA/W for a DC bias of 15V at room temperature.
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| 6. |
- Yoshihara, Masato, et al.
(author)
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Does complete-staging lymphadenectomy improve survival outcomes in stage I endometrioid epithelial ovarian carcinoma? A multi-institutional retrospective study with propensity score-weighted analysis
- 2021
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In: Japanese journal of clinical oncology. - : Oxford University Press (OUP). - 1465-3621. ; 51:3, s. 387-392
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Journal article (peer-reviewed)abstract
- BACKGROUND: We investigated the prognostic impact of complete-staging lymphadenectomy on patients with clinically apparent Stage I endometrioid epithelial ovarian carcinoma. METHODS: We conducted a regional multi-institutional retrospective study between 1986 and 2018. Amongst 4897 patients with malignant ovarian tumours diagnosed under central pathological review, 259 women with Stage I endometrioid epithelial ovarian carcinoma were eligible. We evaluated differences in survival of patients with both pelvic and para-aortic lymphadenectomy (Group A) and those with only pelvic lymphadenectomy and/or clinical lymph node evaluation (Group B). To analyse the therapeutic effects, the baseline imbalance between patients with both pelvic and para-aortic lymphadenectomy and others was adjusted with an inverse probability of treatment weighting using propensity score involving independent clinical variables. RESULTS: In total, 145 patients (56.0%) received both pelvic and para-aortic lymphadenectomy. With propensity score-based adjustment, estimated survival was better in Group A compared with that in Group B but not significant. Pelvic and para-aortic lymphadenectomy also led to no significant improvement of overall survival in most of the subgroups. However, point estimations of the hazard ratio for lymphadenectomy in patients with an age of 45 or younger (hazard ratio, 0.304; 95% confidence interval, 0.094-0.982), a Grade 1-2 (hazard ratio, 0.441; 95% confidence interval, 0.204-0.954) and T1c2-3 tumour (hazard ratio, 0.449; 95% confidence interval, 0.164-1.231) were better compared with those with the opposite characteristics. CONCLUSIONS: Complete-staging lymphadenectomy was not a significant prognostic factor in patients with Stage I endometrioid epithelial ovarian carcinoma, where we still need to explore appropriate candidate for the procedure.
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| 7. |
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- 2019
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Journal article (peer-reviewed)
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