Development and On-sky Demonstration of Atmospheric Turbulence Profiler for Future Adaptive Optics with Multiple Laser Guide Stars

Tohoku University博士（理学）thesi

Development and On-sky Demonstration of Atmospheric Turbulence Profiler for Future Adaptive Optics with Multiple Laser Guide Stars

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UBVRI photometry of Betelgeuse over 23 years since 1999

We report the results of our continuous UBVRI-band photometry of Betelgeuse from 1999 to 2022 using the same photometric system. There are two advantages in our observation: (1) we used a photodiode as a detector to avoid saturation, and (2) our data set includes U-band light curve, which is not widely observed in recent CCD photometries. Using our light curves, we conducted the periodicity analysis, and found ~405- and ~2160-day periods. We also discuss the tentative detection of a long-period variation over 20 years or longer. Finally, we discuss the peculiar variation of the U-B color index during the "Great Dimming" event between late 2019 and early 2020.Comment: 29 pages, 7 figures, 2 tables. Published in OEJV. Full tables available as table1.dat and table2.da

High-field magnetization and magnetic phase transition in CeOs2Al10

We have studied the magnetization of CeOs2Al10 in high magnetic fields up to 55 T for H // a and constructed the magnetic phase diagram for H // a. The magnetization curve shows a concave H dependence below T_max \sim40 K which is higher than the transition temperature T_0 \sim29 K. The magnetic susceptibility along the a-axis shows a smooth and continuous decrease down to \sim20 K below T_max \sim40 K without showing an anomaly at T_0. From these two results, a Kondo singlet is formed below T_max and coexists with the antiferro magnetic order below T_0. We also propose that the larger suppression of the spin degrees of freedom along the a-axis than along the c-axis below T_max is associated with the origin of the antiferro magnetic component.Comment: 4 pages, 4 figures, to appear in Phys. Rev. B, Rapid Commu

High-field magnetization and magnetic phase transition in CeOs2Al10

We have studied the magnetization of CeOs2Al10 in high magnetic fields up to 55 T for H // a and constructed the magnetic phase diagram for H // a. The magnetization curve shows a concave H dependence below T_max \sim40 K which is higher than the transition temperature T_0 \sim29 K. The magnetic susceptibility along the a-axis shows a smooth and continuous decrease down to \sim20 K below T_max \sim40 K without showing an anomaly at T_0. From these two results, a Kondo singlet is formed below T_max and coexists with the antiferro magnetic order below T_0. We also propose that the larger suppression of the spin degrees of freedom along the a-axis than along the c-axis below T_max is associated with the origin of the antiferro magnetic component.Comment: 4 pages, 4 figures, to appear in Phys. Rev. B, Rapid Commu

Empirical studies on the future prospects of new firms and the assessment abilities of financial institutions

70801968 (科研費)南山大学新規開業企業の将来性と金融機関の目利き能力に関する実証分析 2019～2022年度科学研究費助成事業 (若手研究) 研究成果報告書書33917 (科研費)202219K13746 (科研費)research repor