CTA 102, classified as a flat spectrum radio quasar at z = 1.037, produced an exceptionally bright optical flare in 2012 September. Following the Fermi Large Area Telescope detection of enhanced γ-ray activity, we closely monitored this source in the optical and near-infrared bands for the 10 subsequent nights using 12 telescopes in Japan and South Africa. On MJD 56197 (2012 September 27, four to five days after the peak of bright γ-ray flare), polarized flux showed a transient increase, while total flux and polarization angle (PA) remained almost constant during the "orphan polarized-flux flare." We also detected an intra-night and prominent flare on MJD 56202. The total and polarized fluxes showed quite similar temporal variations, but the PA again remained constant during the flare. Interestingly, the PAs during the two flares were significantly different from the jet direction. The emergence of a new emission component with a high polarization degree (PD) up to 40% would be responsible for the observed two flares, and such a high PD indicates the presence of a highly ordered magnetic field at the emission site. We argue that the well-ordered magnetic field and even the observed directions of the PA, which is grossly perpendicular to the jet, are reasonably accounted for by transverse shock(s) propagating down the jet.
Abstract Crystals of the title compound are prepared by transferring EtOH into a flask containing stoichiometric quantities of SnI 2 and MeNH 3 I (65 °C followed by cooling to 5 °C, 10—30% yield).
Recently, it was shown that the shape of lightning-generated induction magnetic field waveforms in the ELF frequency range is well comparable to that of lightning current waveforms. Therefore, charge amounts of any lightning discharges occurring within the area where the induction magnetic fields are measured can be easily estimated from ELF waveforms by quantitatively evaluating the relation between ELF waveforms and the current waveforms. In this study, we analyzed lightning current waveforms measured by a Rogowski coil installed at Mt. Ogkami and ELF waveforms measured at Onagawa observatory. Based on the quantitative comparison between the ELF waveforms and the current waveforms, empirical equations that enable us to directly convert from the magnetic field intensities into the current intensities and charge amount were obtained. Furthermore, using ELF waveform data obtained at Kuju station in Kyushu and the Japan Lightning Detection Network (JLDN) lightning data, peak current values and charge amounts for the lightning discharges occurring when severe downbursts occurred in the Kanto Plain were estimated by applying the empirical equations. Then, we newly found a clear feature showing that the time variation of charge amounts drastically changed just before the downburst onset.
