Kiyoshi Sakimoto

OPTICAL AND NEAR-INFRARED POLARIMETRY OF HIGHLY REDDENED Type Ia SUPERNOVA 2014J: PECULIAR PROPERTIES OF DUST IN M82

We presented optical and near-infrared multi-band linear polarimetry of the highly reddened Type Ia SN~2014J appeared in M82. SN~2014J exhibits large polarization at shorter wavelengths, e.g.,

GRB 091208B: FIRST DETECTION OF THE OPTICAL POLARIZATION IN EARLY FORWARD SHOCK EMISSION OF A GAMMA-RAY BURST AFTERGLOW

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Bayesian Approach to Find a Long-Term Trend in Erratic Polarization Variations Observed in Blazars

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Extremely High Polarization in the 2010 Outburst of Blazar 3C 454.3

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A Study of the Long-term Spectral Variations of 3C 66A Observed with the Fermi and Kanata Telescopes

band, and the polarization decreases rapidly at longer wavelengths, with the position angle of the polarization remaining at approximately

Early Spectroscopy of the 2010 Outburst of U Scorpii

40^{\circ}

Rapidly‐Responding Optical Polarimetry of GRB afterglows with Hiroshima 1.5‐m Telescope and One‐shot Wide‐field Polarimeter

over the observed wavelength range. These polarimetric properties suggest that the observed polarization is likely to be caused predominantly by the interstellar dust within M82. Further analysis shows that the polarization peaks at a wavelengths much shorter than those obtained for the Galactic dust. The wavelength dependence of the polarization can be better described by an inverse power law rather than by Serkowski law for Galactic interstellar polarization. These suggests that the nature of the dust in M82 may be different from that in our Galaxy, with polarizing dust grains having a mean radius of

THE STRUCTURE AND EMISSION MODEL OF THE RELATIVISTIC JET IN THE QUASAR 3C 279 INFERRED FROM RADIO TO HIGH-ENERGY γ-RAY OBSERVATIONS IN 2008-2010

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Photopolarimetric Monitoring of Blazars in the Optical and Near-Infrared Bands with the Kanata Telescope. I. Correlations between Flux, Color, and Polarization

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Prominent Polarized Flares of the Blazars AO 0235164 and PKS 1510089

We report that the optical polarization in the afterglow of GRB 091208B is measured at t = 149-706 s after the burst trigger, and the polarization degree is P = 10.4{ ± 2.5%. The optical light curve at this time shows a power-law decay with index –0.75 ± 0.02, which is interpreted as the forward shock synchrotron emission, and thus this is the first detection of the early-time optical polarization in the forward shock (rather than that in the reverse shock reported by Steele et al.). This detection disfavors the afterglow model in which the magnetic fields in the emission region are random on the plasma skin depth scales, such as those amplified by the plasma instabilities, e.g., Weibel instability. We suggest that the fields are amplified by the magnetohydrodynamic instabilities, which would be tested by future observations of the temporal changes of the polarization degrees and angles for other bursts.