Search

Catalytic asymmetric iodoesterification of simple alkenes was achieved using a dinuclear zinc-3,3'-(R,S,S)-bis(aminoimino)binaphthoxide (di-Zn) complex. For iodoesterification using p-methoxybenzoic acid, the N-iodonaphthalenimide (NIN)-I2 system was effective for producing iodoesters in a highly enantioselective manner. The synthetic utility of chiral iodo-p-methoxybenzoates was also demonstrated. The quartet of metal ionic bond, hydrogen bond, halogen bond, and π-π stacking is harmonized on the single reaction sphere of di-Zn catalyst for enabling the highly enantioselective catalytic asymmetric iodoesterification of simple alkenes for the first time.

Itoh, R and Hirose, N. Relationship among biological maturation, physical characteristics, and motor abilities in youth elite soccer players. J Strength Cond Res 34(2): 382-388, 2020-Studies investigating skeletal maturity and motor abilities in youth Asian elite soccer players are lacking. We aimed to investigate the cross-sectional relationship among skeletal age (SA), physical characteristics, and motor abilities in youth elite soccer players. Skeletal age is commonly used to estimate the maturity status of youth athletes using a hand-wrist radiograph. We enrolled 49 youth elite male soccer players (12.7 ± 0.2 years). Height, body mass, body fat percentage, circumference (thigh/calf), flexibility, 10-m/50-m sprint, 10-m × 5 shuttle run, the crank test, 5-step bounding, Yo-Yo intermittent recovery test level 2, and cooper run were measured. Participants were divided into early (n = 14), average (n = 22), and late (n = 13) maturation groups according to their chronological age (CA) and SA based on the following criteria: SA-CA-1 year, SA-CA = ±1 year, and SA-CA+1 year, respectively. The difference in parameters among the groups was analyzed using one-way analysis of variance and Tukey's post hoc test. Statistical significance was set at p0.05. The early and average maturation groups were taller and heavier and had a larger circumference than the late maturation group (p0.05). Conversely, the early and average groups were significantly faster in 50-m sprint (p0.05) and scored higher in 5-step bounding (p0.05) than the late group. There was no difference in other parameters among the groups. In conclusion, the difference in biological maturity influences physical and physiological development, particularly height and muscular power, in youth elite soccer players.

The astrophysical journal 932(1), 40 (2022). doi:10.3847/1538-4357/ac6c29, The Fermi Gamma-ray Burst Monitor (GBM) triggers on-board in response to ∼40 short gamma-ray bursts (SGRBs) per year; however, their large localization regions have made the search for optical counterparts a challenging endeavour. We have developed and executed an extensive program with the wide field of view of the Zwicky Transient Facility (ZTF) camera, mounted on the Palomar 48 inch Oschin telescope (P48), to perform target-of-opportunity (ToO) observations on 10 Fermi-GBM SGRBs during 2018 and 2020–2021. Bridging the large sky areas with small field-of-view optical telescopes in order to track the evolution of potential candidates, we look for the elusive SGRB afterglows and kilonovae (KNe) associated with these high-energy events. No counterpart has yet been found, even though more than 10 ground-based telescopes, part of the Global Relay of Observatories Watching Transients Happen (GROWTH) network, have taken part in these efforts. The candidate selection procedure and the follow-up strategy have shown that ZTF is an efficient instrument for searching for poorly localized SGRBs, retrieving a reasonable number of candidates to follow up and showing promising capabilities as the community approaches the multi-messenger era. Based on the median limiting magnitude of ZTF, our searches would have been able to retrieve a GW170817-like event up to ∼200 Mpc and SGRB afterglows to z = 0.16 or 0.4, depending on the assumed underlying energy model. Future ToOs will expand the horizon to z = 0.2 and 0.7, respectively., Published by Univ., Chicago, Ill. [u.a.]

We followed up the massive young stellar object S255-NIRS3 (= S255-IRS1b) during its recent accretion outburst event in the $K_{\rm s}$ band with Kanata/HONIR for four years after its burst and obtained a long-term light curve. This is the most complete near-infrared light curve of the S255-NIRS3 burst event that has ever been presented. The light curve showed a steep increase reaching a peak flux that was 3.4 mag brighter than the quiescent phase and then a relatively moderate year-scale fading until the last observation, similar to that of the accretion burst events such as EXors found in lower-mass young stellar objects. The behavior of the $K_{\rm s}$-band light curve is similar to that observed in 6.7 GHz class II methanol maser emission, with a sudden increase followed by moderate year-scale fading. However, the maser emission peaks appear 30–50 d earlier than that of the $K_{\rm s}$ band emission. The similarities confirmed that the origins of the maser emission and the $K_{\rm s}$-band continuum emission are common, as previously shown from other infrared and radio observations by Stecklum et al. (2016, Astronomer’s Telegram, 8732), Caratti o Garatti et al. (2017b, Nature Phys., 13, 276), and Moscadelli et al. (2017, A&A, 600, L8). However, the differences in energy transfer paths, such as the exciting/emitting/scattering structures, may cause the delay in the flux-peak dates.

The Belle II experiment is a new generation B-factory experiment at KEK in Japan aiming at the search for New Physics in a huge sample of B-meson dacays. The commissioning of accelerator and detector for the first physics run has been started from March this year. The Belle II High Level Trigger (HLT) is fully working in the beam run. The HLT is now operated with 1600 cores clusterized in 5 units of 16 processing servers, which is the 1/4 of full configuration. In each unit, the event-by-event basis parallel processing is implemented using the IPC-based ring buffers with the event transport over the network socket connection. The load balancing is automatically ensured by the ring buffers. In each processing server with 20 cores, the parallel processing is implemented utilizing the multi-process approach to run the same code for different events without taking a special care. The copy-on-write fork of processes efficiently reduces the memory consumption. The event selection is done using the same offline code in two steps. The first is the track finding and the calorimeter clustering, and the rough event selection is performed to discard off-vertex background events efficiently. The full event reconstruction is performed for the selected events and they are classified in multiple categories. Only the events in the categories of interest are finally sent out to the storage. The live data quality monitoring is also performed on HLT. For the selected events, the reconstructed tracks are extrapolated to the surface of pixel detector(PXD) and lively fed back to the readout electronics for the real time data reduction by sending only the associated hits. Currently the accelerator study is still on-going to increase the luminosity and the physics data taking is being performed by sharing the time. During the data taking, sometimes the background rate becomes high and the L1 trigger rate reaches close to 10kHz, which is the 1/3 of maximum design rate. In this condition, the performance of Belle II HLT is discussed with the detailed report on various kinds of troubles and their fixes.

At the high luminosity flavor factory experiments such as the Belle II experiment, it is expected to find the new physics effect and constrain the new physics models with the high statics and many observables. In such analysis, the global analysis of the many observables with the model-independent approach is important. One difficulty in such global analysis is that the new physics could affect the numerical results obtained by experiments assuming the Standard Model, because of the changes of the reconstructed kinematical distributions used in the event selection and in the fitting to obtain the number of signal and background events. Therefore, it is also important to prepare the event generator including the new physics effects for the Monte Carlo simulation of the detector response to estimate and consider the effects properly in the global analysis. In this work, we present development of the event generator of B->K(*)ll decays including the new physics effect in the model-independent way by parametrizing with the Wilson coefficients. We implement the decay model using the EvtGen [https://evtgen.hepforge.org/] framework so that it can be applicable in the analysis software framework of the B physics experiments. For the theoretical calculation of the new physics effect we consider the EOS [https://eos.github.io/] library and other possible calculations. We report the results obtained by the developed event generator and application in the global analysis.

We performed deep spectropolarimetric observations of a prototypical starburst galaxy M82 with the Subaru Telescope in order to study the kinematics of the dust outflow. We obtained optical polarized emission-line spectra up to $\sim$4~kpc away from the nucleus of the galaxy along three position angles within the conical outflowing wind (superwind). The H$\alpha$ emission line in the superwind is strongly polarized and the polarization pattern shows dust scattering of central light sources, being consistent with the previous works. The intensity weighted polarization degree of the H$\alpha$ line reaches $\sim$30\%\ at maximum. There are at least two light sources at the central region of the galaxy; one of which is located at the near-infrared nucleus and the other resides at one of the peaks of the 3 mm radio and molecular gas emission. The outer (> 1 kpc) dust is illuminated by the former, whereas the inner dust is scattering the light from the latter. We investigated as well the dust motion from the velocity field of the polarized H$\alpha$ emission line. The dust is accelerated outward on the northwest side of the nucleus. A simple bi-conical dust outflow model shows that the outflow velocity of the dust reaches $\gtrsim 300-450$ km/s at $\sim 4$ kpc from the nucleus, suggesting that some portion of the dust escapes from the gravitational potential of M82 into the intergalactic space. At some regions on the southeast side, in particular along the position angle of 138$^\circ$, the dust has radial velocity slower than the systemic velocity of the galaxy, apparently suggesting inflowing motion toward the nucleus. These components are spatially consistent with a part of the molecular gas stream, which is kinematically independent of the outflow gas, thus the apparent inflow motion of the dust reflects the streaming motion associated with the molecular gas stream., Comment: 24 pages, 36 figures, accpected for publication in PASJ. Figures 28--36 can be found at https://home.hiroshima-u.ac.jp/~yoshidam/M82-sp/figures28-36.zip

We report results from X-ray and optical observations of the Galactic black hole candidate MAXI J1828-249, performed with Suzaku and the Kanata telescope around the X-ray flux peak in the 2013 outburst. The time-averaged X-ray spectrum covering 0.6--168 keV was approximately characterized by a strong multi-color disk blackbody component with an inner disk temperature of ~0.6 keV, and a power-law tail with a photon index of ~2.0. We detected an additional structure at 5-10 keV, which can be modelled neither with X-ray reflection on the disk, nor relativistic broadening of the disk emission. Instead, it was successfully reproduced with a Comptonization of disk photons by thermal electrons with a relatively low temperature (, Comment: 18 pages, 9 figures and 3 tables, Accepted for publication in PASJ

We present optical and near-infrared observations of the nearby Type Iax supernova (SN) 2014dt from 14 to 410 days after the maximum light. The velocities of the iron absorption lines in the early phase indicated that SN 2014dt showed slower expansion than the well-observed Type Iax SNe 2002cx, 2005hk and 2012Z. In the late phase, the evolution of the light curve and that of the spectra were considerably slower. The spectral energy distribution kept roughly the same shape after ~100 days, and the bolometric light curve flattened during the same period. These observations suggest the existence of an optically thick component that almost fully trapped the {\gamma}-ray energy from 56 Co decay. These findings are consistent with the predictions of the weak deflagration model, leaving a bound white dwarf remnant after the explosion., Comment: 39 pages, 14 figures, accepted for publication in PASJ

We present recent optical photometric observations of the blazar OJ 287 taken during September 2015 -- May 2016. Our intense observations of the blazar started in November 2015 and continued until May 2016 and included detection of the large optical outburst in December 2016 that was predicted using the binary black hole model for OJ 287. For our observing campaign, we used a total of 9 ground based optical telescopes of which one is in Japan, one is in India, three are in Bulgaria, one is in Serbia, one is in Georgia, and two are in the USA. These observations were carried out in 102 nights with a total of ~ 1000 image frames in BVRI bands, though the majority were in the R band. We detected a second comparably strong flare in March 2016. In addition, we investigated multi-band flux variations, colour variations, and spectral changes in the blazar on diverse timescales as they are useful in understanding the emission mechanisms. We briefly discuss the possible physical mechanisms most likely responsible for the observed flux, colour and spectral variability., 11 pages, 6 figures, 4 tables; Accepted for publication in MNRAS

We present a multi-wavelength spectral and temporal analysis of the blazar OJ 287 during its recent activity between December 2015 -- May 2016, showing strong variability in the near-infrared (NIR) to X-ray energies with detection at $\gamma$-ray energies as well. Most of the optical flux variations exhibit strong changes in polarization angle and degree. All the inter-band time lags are consistent with simultaneous emissions. Interestingly, on days with excellent data coverage in the NIR--UV bands, the spectral energy distributions (SEDs) show signatures of bumps in the visible--UV bands, never seen before in this source. The optical bump can be explained as accretion-disk emission associated with the primary black hole of mass $\sim \rm 1.8 \times10^{10} M_{\odot}$ while the little bump feature in the optical-UV appears consistent with line emission. Further, the broadband SEDs extracted during the first flare and during a quiescent period during this span show very different $\gamma$-ray spectra compared to previously observed flare or quiescent spectra. The probable thermal bump in the visible seems to have been clearly present since May 2013, as found by examining all available NIR-optical observations, and favors the binary super-massive black hole model. The simultaneous multi-wavelength variability and relatively weak $\gamma$-ray emission that shows a shift in the SED peak is consistent with $\gamma$-ray emission originating from inverse Compton scattering of photons from the line emission that apparently contributes to the little blue bump., Comment: 24 pages, 6 figures, 2 tables, MNRAS in press

We report on a recent multi-band optical photometric and polarimetric observational campaign of the blazar OJ 287 which was carried out during September 2016 -- December 2017. We employed nine telescopes in Bulgaria, China, Georgia, Japan, Serbia, Spain and the United States. We collected over 1800 photometric image frames in BVRI bands and over 100 polarimetric measurements over ~175 nights. In 11 nights with many quasi-simultaneous multi-band (V, R, I) observations, we did not detect any genuine intraday variability in flux or color. On longer timescales, multiple flaring events were seen. Large changes in color with respect to time and in a color--magnitude diagram were seen, and while only a weak systematic variability trend was noticed in color with respect to time, the color--magnitude diagram shows a bluer-when-brighter trend. Large changes in the degree of polarization, and substantial swings in the polarization angle were detected. The fractional Stokes parameters of the polarization showed a systematic trend with time in the beginning of these observations, followed by chaotic changes and then an apparently systematic variation at the end. These polarization changes coincide with the detection and duration of the source at very high energies as seen by VERITAS. The spectral index shows a systematic variation with time and V-band magnitude. We briefly discuss possible physical mechanisms that could explain the observed flux, color, polarization, and spectral variability., Comment: 16 pages, 8 figures, 7 tables; Accepted for Publication to AJ

We have monitored the R-band optical linear polarisation of ten jetted NLSy1 galaxies with the aim to quantify their variability and search for candidate long rotation of the polarisation plane. In all cases for which adequate datasets are available we observe significant variability of both the polarisation fraction and angle. In the best-sampled cases we identify candidate long rotations of the polarisation plane. We present an approach that assesses the probability that the observed phenomenology is the result of pure noise. We conclude that although this possibility cannot be excluded it is much more likely that the EVPA undergoes an intrinsic evolution. We compute the most probable parameters of the intrinsic event which forecasts events consistent with the observations. In one case we find that the EVPA shows a preferred direction which, however, does not imply any dominance of a toroidal or poloidal component of the magnetic field at those scales., Presented at the conference "Revisiting narrow-line Seyfert 1 galaxies and their place in the Universe" (9-13 April 2018, Padova Botanical Garden, Italy) and is included in Volume 328 of the PoS as article 019

Narrow line Seyfert 1 galaxies (NLSy1s) constitute the AGN subclass associated with systematically smaller black hole masses. A few radio loud ones have been detected in MeV -- GeV energy bands by Fermi and evidence for the presence of blazar-like jets has been accumulated. In this study we wish to quantify the temporal behaviour of the optical polarisation, fraction and angle, for a selected sample of radio loud NLSy1s. We also search for rotations of the polarisation plane similar to those commonly observed in blazars. We have conducted R-band optical polarisation monitoring of a sample of 10 RL NLSy1s 5 of which have been previously detected by Fermi. The dataset includes observations with the RoboPol, KANATA, Perkins and Steward polarimeters. In the cases where evidences for long rotations of the polarisation plane are found, we carry out numerical simulations to assess the probability that they are caused by intrinsically evolving EVPAs instead of observational noise. Even our moderately sampled sources show indications of variability, both in polarisation fraction and angle. For the four best sampled objects in our sample we find multiple periods of significant polarisation angle variability. In the two best sampled cases, namely J1505+0326 and J0324+3410, we find indications for three long rotations. We show that although noise can induce the observed behaviour, it is much more likely that the apparent rotation is caused by intrinsic evolution of the EVPA. To our knowledge this is the very first detection of such events in this class of sources. In the case of the largest dataset (J0324+3410) we find that the EVPA concentrates around a direction which is at 49.3\degr to the 15-GHz radio jet implying a projected magnetic field at an angle of 40.7\degr to that axis., Comment: Accepted for publication in section 2. Astrophysical processes of Astronomy and Astrophysics

The long gamma-ray burst GRB 161017A was detected by Fermi and Swift, and its afterglow was observed by the MITSuME 50-cm optical telescope promptly about 50 s after the burst. Early optical observations revealed that the optical lightcurve exhibits a plateau and rebrightening in the early afterglow phase about 500 and 5000 s after the trigger, respectively. By investigating the behavior of the spectral and temporal flux variation, it was found that the plateau and re-brightening cannot be explained in the context of the simple standard afterglow model. These observational features can be explained with two independent refreshed shocks, which indicate the long-acting central engine. We evaluated the physical parameters of the subsequent shells, and we then determined the kinetic energy ratio of the two colliding shells to the leading shell to be roughly 1 and 8, respectively. In addition, two prominent X-ray flares about 200 s after the trigger may be signatures of delayed ejections of the energetic jets responsible for the refreshed shocks. Such late activity of the central engine and X-ray flares play a crucial role in understanding the mechanisms for jet formation and photon emission.

The spectral energy distributions (SEDs) of blazars are dominated by synchrotron and inverse Compton radiation. The origin of blazar variability can be investigated from the time variation of the SEDs. In the present study, we used Markov chain Monte Carlo (MCMC) method to estimate the optimal model parameters of SEDs and their uncertainties. Our experiments using artificial data demonstrate that at least one prior probability is required to uniquely determine the solution. We used simultaneous observations of Mrk 421 with Fermi-LAT, Swift-XRT, and the 1.5-m optical telescope, Kanata from 2009 to 2011 reported in Itoh et al. (2015). We succeeded in estimating the optimal parameters and their uncertainties by using the prior probability of the variation time-scale and Doppler factor. We found that the power-law index of the electron energy distribution shows a clear positive correlation with the X-ray flux even if the uncertainties are considered.

We report on the variation in the optical polarization of the blazar PKS 1749+096 observed in 2008--2015. The degree of polarization (PD) tends to increase in short flares having a time-scale of a few days. The object favors a polarization angle (PA) of $40^\circ$--$50^\circ$ at the flare maxima, which is close to the position angle of the jet ($20^\circ$--$40^\circ$). Three clear polarization rotations were detected in the negative PA direction associated with flares. In addition, a rapid and large decrease in the PA was observed in the other two flares, while another two flares showed no large PA variation. The light curve maxima of the flares possibly tend to lag behind the PD maxima and color-index minima. The PA became $-50^\circ$ to $-20^\circ$ in the decay phase of active states, which is almost perpendicular to the jet position angle. We propose a scenario to explain these observational features, where transverse shocks propagate along curved trajectories. The favored PA at the flare maxima suggests that the observed variations were governed by the variations in the Doppler factor, $\delta$. Based on this scenario, the minimum viewing angle of the source, $\theta_\mathrm{min}=4.8^\circ$--$6.6^\circ$, and the location of the source, $\Delta r\gtrsim 0.1$pc, from the central black hole were estimated. In addition, the acceleration of electrons by the shock and synchrotron cooling would have a time-scale similar to that of the change in $\delta$. The combined effect of the variation in $\delta$ and acceleration/cooling of electrons is probably responsible for the observed diversity of the polarization variations in the flares., Comment: 12 pages, 9 figures, accepted for publication in PASJ

The first detected gravitational wave from a neutron star merger was GW170817. In this study, we present J-GEM follow-up observations of SSS17a, an electromagnetic counterpart of GW170817. SSS17a shows a 2.5-mag decline in the $z$-band from 1.7 days to 7.7 days after the merger. Such a rapid decline is not comparable with supernovae light curves at any epoch. The color of SSS17a also evolves rapidly and becomes redder for later epochs; the $z-H$ color changed by approximately 2.5 mag in the period of 0.7 days to 7.7 days. The rapid evolution of both the optical brightness and the color are consistent with the expected properties of a kilonova that is powered by the radioactive decay of newly synthesized $r$-process nuclei. Kilonova models with Lanthanide elements can reproduce the aforementioned observed properties well, which suggests that $r$-process nucleosynthesis beyond the second peak takes place in SSS17a. However, the absolute magnitude of SSS17a is brighter than the expected brightness of the kilonova models with the ejecta mass of 0.01 $\Msun$, which suggests a more intense mass ejection ($\sim 0.03 \Msun$) or possibly an additional energy source., Comment: 7 pages, 5 figures. Published in PASJ (Publications of the Astronomical Society of Japan)

We demonstrate improved optical sectioning in light sheet fluorescence microscopy using tunable structured illumination (SI) frequencies to optimize image quality in scattering specimens. The SI patterns are generated coherently using a one-dimensional spatial light modulator for maximum pattern contrast, and the pattern spatial frequency is adjustable up to half the incoherent cutoff frequency of our detection objective. At this frequency, we demonstrate background reductions of 2 orders of magnitude.

Blazars are highly variable active galactic nuclei which emit radiation at all wavelengths from radio to gamma-rays. Polarized radiation from blazars is one key piece of evidence for synchrotron radiation at low energies and it also varies dramatically. The polarization of blazars is of interest for understanding the origin, confinement, and propagation of jets. However, even though numerous measurements have been performed, the mechanisms behind jet creation, composition and variability are still debated. We performed simultaneous gamma-ray and optical photopolarimetry observations of 45 blazars between Jul. 2008 and Dec. 2014 to investigate the mechanisms of variability and search for a basic relation between the several subclasses of blazars. We identify a correlation between the maximum degree of optical linear polarization and the gamma-ray luminosity or the ratio of gamma-ray to optical fluxes. Since the maximum polarization degree depends on the condition of the magnetic field (chaotic or ordered), this result implies a systematic difference in the intrinsic alignment of magnetic fields in pc-scale relativistic jets between different types blazars (FSRQs vs. BL Lacs), and consequently between different types of radio galaxies (FR Is vs. FR IIs)., Comment: 17 pages, 30 figures, 6 tables. Accepted for publication in Astrophysical Journal

Here we report on the results of the WEBT photo-polarimetric campaign targeting the blazar S5~0716+71, organized in March 2014 to monitor the source simultaneously in BVRI and near IR filters. The campaign resulted in an unprecedented dataset spanning $\sim 110$\,h of nearly continuous, multi-band observations, including two sets of densely sampled polarimetric data mainly in R filter. During the campaign, the source displayed pronounced variability with peak-to-peak variations of about $30\%$ and "bluer-when-brighter" spectral evolution, consisting of a day-timescale modulation with superimposed hourlong microflares characterized by $\sim 0.1$\,mag flux changes. We performed an in-depth search for quasi-periodicities in the source light curve; hints for the presence of oscillations on timescales of $\sim 3$\,h and $\sim 5$\,h do not represent highly significant departures from a pure red-noise power spectrum. We observed that, at a certain configuration of the optical polarization angle relative to the positional angle of the innermost radio jet in the source, changes in the polarization degree led the total flux variability by about 2\,h; meanwhile, when the relative configuration of the polarization and jet angles altered, no such lag could be noted. The microflaring events, when analyzed as separate pulse emission components, were found to be characterized by a very high polarization degree ($> 30\%$) and polarization angles which differed substantially from the polarization angle of the underlying background component, or from the radio jet positional angle. We discuss the results in the general context of blazar emission and energy dissipation models., 16 pages, 17 Figures; ApJ accepted

著者人数: 42名, Accepted: 2016-03-14, 資料番号: SA1160038000

We report X-ray, optical, and near-infrared monitoring of the new X-ray transient MAXI J1820$+$070 discovered with MAXI on 2018 March 11. Its X-ray intensity reached $\sim 2$ Crab in 2--20 keV at the end of March, and then gradually decreased until the middle of June. In this period, the X-ray spectrum was described by Comptonization of the disk emission, with a photon index of $\sim$1.5 and an electron temperature of $\sim$50 keV, which is consistent with a black hole X-ray binary in the low/hard state. The electron temperature and the photon index were slightly decreased and increased with increasing flux, respectively. The source showed significant X-ray flux variation on timescales of seconds. This short-term variation was found to be associated with changes in the spectral shape, and the photon index became slightly harder at higher fluxes. This suggests that the variation was produced by a change in the properties of the hot electron cloud responsible for the strong Comptonization. Modeling a multi-wavelength SED around the X-ray flux peak at the end of March, covering the near-infrared to X-ray bands, we found that the optical and near-infrared fluxes were likely contributed substantially by the jet emission. Before this outburst, the source was never detected in the X-ray band with MAXI (with a 3$\sigma$ upper limit of $\sim$0.2 mCrab in 4--10 keV, obtained from the 7-year data in 2009--2016), whereas weak optical and infrared activity was found at their flux levels $\sim$3 orders of magnitude lower than the peak fluxes in the outburst., Comment: 14 pages, 9 figures, accepted for publication in ApJ

We analyze the linear polarization of the relativistic jet in BL Lacertae object OJ 287 as revealed by multi-epoch Very Long Baseline Array images at 43 GHz and monitoring observations at optical bands. The electric-vector position angle of the optical polarization matches that at 43 GHz at locations that are often in the compact millimeter-wave >core> or, at other epochs, coincident with a bright, quasi-stationary emission feature ∼0.2 mas (∼0.9 pc projected on the sky) downstream from the core. This implies that electrons with high enough energies to emit optical synchrotron and γ-ray inverse Compton radiation are accelerated both in the core and at the downstream feature, the latter of which lies ≥10 pc from the central engine. The polarization vector in the stationary feature is nearly parallel to the jet axis, as expected for a conical standing shock capable of accelerating electrons to GeV energies.© 2018. The American Astronomical Society. All rights reserved.., The authors thank Dr. Ioannis Myserlis for a critical review of a draft of this manuscript. The authors acknowledge financial support by MEXT/JSPS Grant-in-Aid for Scientific Research on Innovative Areas (No. 25120007). M.S. was supported during this study by a JSPS Postdoctoral Fellowship for Research Abroad. The research at Boston University was supported in part by National Science Foundation grant AST-1615796 and NASA Fermi Guest Investigator Program grants NNX14AQ58G and 80NSSC17K0649. The St. Petersburg University team acknowledges support from Russian Science Foundation grant 17-12-01029. I.A. acknowledges support by a Ramon y Cajal grant of the Ministerio de Economia y Competitividad (MINECO) of Spain. The research at the IAA-CSIC was supported in part by the MINECO through grants AYA2016-80889-P, AYA2013-40825-P, and AYA2010-14844; and by the regional government of Andalucia through grant P09-FQM-4784. Calar Alto Observatory is jointly operated by the Max-Planck-Institut fur Astronomie and the IAA-CSIC. The VLBA is an instrument of the Long Baseline Observatory (LBO). The LBO is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. Data from the Steward Observatory spectro-polarimetric monitoring project were used. This program was supported by Fermi Guest Investigator grants NNX08AW56G, NNX09AU10G, NNX12AO93G, and NNX15AU81G.

During the month of 2009 December, the blazar 3C 454.3 became the brightest gamma-ray source in the sky, reaching a peak flux F 2000 × 10 -8 photons cm-2 s-1 for E > 100 MeV. Starting in 2009 November intensive multifrequency campaigns monitored the 3C 454 gamma-ray outburst. Here, we report on the results of a two-month campaign involving AGILE, INTEGRAL, Swift/XRT, Swift/BAT, and Rossi XTE for the high-energy observations and Swift/UVOT, KANATA, Goddard Robotic Telescope, and REM for the near-IR/optical/UV data. GASP/WEBT provided radio and additional optical data. We detected a long-term active emission phase lasting 1 month at all wavelengths: in the gamma-ray band, peak emission was reached on 2009 December 2-3. Remarkably, this gamma-ray super-flare was not accompanied by correspondingly intense emission in the optical/UV band that reached a level substantially lower than the previous observations in 2007-2008. The lack of strong simultaneous optical brightening during the super-flare and the determination of the broadband spectral evolution severely constrain the theoretical modeling. We find that the pre- and post-flare broadband behavior can be explained by a one-zone model involving synchrotron self-Compton plus external Compton emission from an accretion disk and a broad-line region. However, the spectra of the 2009 December 2-3 super-flare and of the secondary peak emission on 2009 December 9 cannot be satisfactorily modeled by a simple one-zone model. An additional particle component is most likely active during these states. © 2010. The American Astronomical Society. All rights reserved.

The Fermi LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include NASA and the Department of Energy in the United States, the Commissariat a l’Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucleaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K. A. Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d’Etudes Spatiales in France. This work was performed in part under DOE Contract DE- AC02-76SF00515.

Casadio, Carolina et. al., We perform a multi-wavelength polarimetric study of the quasar CTA 102 during an extraordinarily bright γ-ray outburst detected by the Fermi Large Area Telescope in 2012 September-October when the source reached a flux of F = 5.2 ± 0.4 × 10 photons cm s. At the same time, the source displayed an unprecedented optical and near-infrared (near-IR) outburst. We study the evolution of the parsec-scale jet with ultra-high angular resolution through a sequence of 80 total and polarized intensity Very Long Baseline Array images at 43 GHz, covering the observing period from 2007 June to 2014 June. We find that the γ-ray outburst is coincident with flares at all the other frequencies and is related to the passage of a new superluminal knot through the radio core. The powerful γ-ray emission is associated with a change in direction of the jet, which became oriented more closely to our line of sight (θ ∼ 1.°2) during the ejection of the knot and the γ-ray outburst. During the flare, the optical polarized emission displays intra-day variability and a clear clockwise rotation of electric vector position angles (EVPAs), which we associate with the path followed by the knot as it moves along helical magnetic field lines, although a random walk of the EVPA caused by a turbulent magnetic field cannot be ruled out. We locate the γ-ray outburst a short distance downstream of the radio core, parsecs from the black hole. This suggests that synchrotron self-Compton scattering of NIR to ultraviolet photons is the probable mechanism for the γ-ray production., This research has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO) grant AYA2013-40825-P. The research at Boston University (BU) was funded in part by NASA Fermi Guest Investigator grants NNX14AQ58G and NNX13AO99G, and Swift Guest Investigator grant NNX14AI96G. I. A. acknowledges support by a Ramon y Cajal grant of the MINECO. The VLBA is operated by the National Radio Astronomy Observatory. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The PRISM camera at Lowell Observatory was developed by K. Janes et al. at BU and Lowell Observatory, with funding from the NSF, BU, and Lowell Observatory. St. Petersburg University team acknowledges support from Russian RFBR grant 15-02-00949 and St. Petersburg University research grant 6.38.335.2015. This research was conducted in part using the Mimir instrument, jointly developed at Boston University and Lowell Observatory and supported by NASA, NSF, and the W.M. Keck Foundation. The Mimir observations were performed by Lauren Cashman, Jordan Montgomery, and Dan Clemens, all from Boston University. This research is partly based on data taken at the IRAM 30 m Telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). The Submillimeter Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica. Data from the Steward Observatory spectropolarimetric monitoring project were used. This program is supported by Fermi Guest Investigator grants NNX08AW56G, NNX09AU10G, and NNX12AO93G. The Metsahovi team acknowledges the support from the Academy of Finland to our observing projects (numbers 212656, 210338, 121148, and others).

We report on long-term multi-wavelength monitoring of blazar Mrk~421 from 2010 to 2011. The source exhibited extreme X-ray flares in 2010. Our research group performed optical photopolarimetric follow-up observations using the Kanata telescope. In 2010, the variability in the X-ray band was significant, while the optical and ultraviolet (UV) flux decreased gradually. Polarization properties also exhibited unique variability in 2010, suggesting the presence of systematic component of polarization and magnetic field alignment for the emergence of a new polarized emission region. In contrast, in 2011 the variability in the X-ray band was smaller, and the variability in the optical and UV bands was larger, than in 2010. To explore the reasons for these differences, spectral fitting analysis was performed via simple synchrotron-self Compton modelling; the results revealed different behaviors in terms of spectral evolution between these periods, suggesting different variability mechanisms between 2010 and 2011. In 2010, the radiation was likely the result of energy injection into the emitting regions with an aligned magnetic field. In contrast, in 2011 the superposition of different emission regions may have contributed to the low degree of observed polarization. It also implies that high-energy electron which were not accelerated to ultra-relativistic velocities were injected in 2011., Comment: 8 pages, 5 figures, 1 table. Accepted by PASJ

The occurrence of low-amplitude flux variations in blazars on hourly timescales, commonly known as microvariability, is still a widely debated subject in high-energy astrophysics. Several competing scenarios have been proposed to explain such occurrences, including various jet plasma instabilities leading to the formation of shocks, magnetic reconnection sites, and turbulence. In this letter we present the results of our detailed investigation of a prominent, five-hour-long optical microflare detected during recent WEBT campaign in 2014, March 2-6 targeting the blazar 0716+714. After separating the flaring component from the underlying base emission continuum of the blazar, we find that the microflare is highly polarized, with the polarization degree $\sim (40-60)\%$$\pm (2-10)\%$, and the electric vector position angle $\sim (10 - 20)$deg$\pm (1-8)$deg slightly misaligned with respect to the position angle of the radio jet. The microflare evolution in the $(Q,\,U)$ Stokes parameter space exhibits a looping behavior with a counter-clockwise rotation, meaning polarization degree decreasing with the flux (but higher in the flux decaying phase), and approximately stable polarization angle. The overall very high polarization degree of the flare, its symmetric flux rise and decay profiles, and also its structured evolution in the $Q-U$ plane, all imply that the observed flux variation corresponds to a single emission region characterized by a highly ordered magnetic field. As discussed in the paper, a small-scale but strong shock propagating within the outflow, and compressing a disordered magnetic field component, provides a natural, though not unique, interpretation of our findings., Comment: 9 pages, 4 Figures, ApJ Letter accepted

Hyaluronic acid and chondroitin were successfully synthesized as representative molecules of glucosaminoglycans and galactosaminoglycans found in a glycosaminoglycan family via enzymatic polymerization catalyzed by testicular hyaluronidases. A newly designed N-acetylhyalobiuronate oxazoline derivative with a β-D-glucuronyl-(1→3)-N-acetyl-D-glucosamine disaccharide structure served as a transition-state analogue substrate monomer for the enzyme, giving rise to artificial hyaluronic acid in 52% yields with a number-average molecular weight of 1.35 × 104 through ring-opening polyaddition in a perfect regioselective and stereoselective manner. A novel N-acetylchondrosine oxazoline derivative with a β-D-glucuronyl-(1→3)-N-acetyl-D-galactosamine disaccharide structure also acted as a transition-state analogue substrate monomer for the enzyme, yielding artificial chondroitin in 35% yields with a number-average molecular weight of 2.5 × 103. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3541–3548, 2003

Optical and near-infrared observations of novae give us useful information for understanding the diversity of nova eruptions. Classical nova V1723 Aql was discovered by F. Kabashima and K. Nishiyama on 2010 September 11. We have conducted photometric and spectroscopic observations of V1723 Aql in both optical and near-infrared (NIR) wavelength regions since its discovery. The V-band decline time by 2 mag after the maximum, t2, was ~12 d. The apparent Fe II emission lines were also seen in the optical spectra. The Rc- and Ic-band light curves exhibited rapid declines (0.16 mag d−1 in Rc) 20 days after the visual maximum, while the NIR (J, H, and Ks) showed slow decline rates (~0.07 mag d−1). This rapid reddening suggests that dust particles formed during the very early phase of the expansion in V1723 Aql.

We have developed an optical and near-infrared instrument HONIR (Hiroshima Optical and Near-InfraRed camera) with imaging, spectroscopy, and polarimetry capabilities in two (one optical and one near-infrared) bands simultaneously. Imaging capability with a field of view of 10 arcmin by 10 arcmin has been available since 2011, as reported in the previous SPIE conference. In addition, spectroscopic and polarimetric optical components (grisms, an Wollaston prism, a half-wave plate, and focal masks) were installed in the instrument, which enabled us to perform spectroscopy and linear polarization measurement by imaging polarimetry and spectro-polarimetry. Spectral resolution of R = λ/(triangle)λ ~ 440 - 800 is achieved in spectroscopy using a slit mask with an 1".3 width. In polarimetry, instrumental polarization is less than ~0.05 % with stability of better than ~0.05 %, which is sufficiently small to achieve an aimed accuracy of polarization measurement of ~0.1 % at primal observing wavelengths.

We developed a new readout system for the near-infrared detector VIRGO-2K (2kx2k HgCdTe array) installed in the optical-infrared simultaneous camera, HONIR, for the 1.5 m Kanata telescope at Higashi-Hiroshima observatory. The main goal of this development is to read out one frame within ~ 1 second through 16 output readout mode of the detector, in order to reduce the overhead time per exposure. The system is based on a CCD controller, Kiso Array Controller (KAC). We redesigned the analog part of KAC to fit VIRGO-2K. We employed a fully differential input circuit and a third order Bessel low-pass filter for noise reduction and a constant current system to improve the linearity of the detector. We set the cutoff frequency of the Bessel low-pass filter at the readout clock rate (120 kHz). We also set the constant current at 200 μA according to the data sheet of VIRGO-2K. We tested the new readout system at room temperature and confirmed that the low-pass filter works well as designed. The fluctuation of the current level of the constant current system is less than 2% for the typical output voltage range of VIRGO-2K (3.2-4.4 V). We measured the readout noise caused by the new readout system (connected to cooled multiplexer) and found that it is 30-40 μV rms, being comparable to or slightly higher than the typical readout noise of VIRGO-2K, ∼ 37 μV rms.

We present a study of SN 2009js in NGC 918. Multi-band Kanata optical photometry covering the first ~120 days show the source to be a Type IIP SN. Reddening is dominated by that due to our Galaxy. One-year-post-explosion photometry with the NTT, and a Subaru optical spectrum 16 days post-discovery, both imply a good match with the well-studied subluminous SN 2005cs. The plateau phase luminosity of SN 2009js and its plateau duration are more similar to the intermediate luminosity IIP SN 2008in. Thus, SN 2009js shares characteristics with both subluminous and intermediate luminosity SNe. Its radioactive tail luminosity lies between SN 2005cs and SN 2008in, whereas its quasi-bolometric luminosity decline from peak to plateau (quantified by a newly-defined parameter Delta[logL] measuring adiabatic cooling following shock breakout) is much smaller than both the others. We estimate the ejected mass of 56Ni to be low (~0.007 Msun). The SN explosion energy appears to have been small, similar to SN 2005cs. SN 2009js is the first subluminous SN IIP to be studied in the mid-infrared. It was serendipitously caught by Spitzer at very early times. In addition, it was detected by WISE 105 days later with a significant 4.6 micron flux excess above the photosphere. The infrared excess luminosity relative to the photosphere is clearly smaller than that of SN 2004dj extensively studied in the mid-infrared. The excess may be tentatively assigned to heated dust with mass ~3e-5 Msun, or to CO fundamental emission as a precursor to dust formation., Comment: Accepted for publication in ApJ

Quasar 3C 279 is known to exhibit episodes of optical polarization angle rotation. We present new, well-sampled optical polarization data for 3C 279 and introduce a method to distinguish between random and deterministic electric vector position angle (EVPA) variations. We observe EVPA rotations in both directions with different amplitudes and find that the EVPA variation shows characteristics of both random and deterministic cases. Our analysis indicates that the EVPA variation is likely dominated by a random process in the low brightness state of the jet and by a deterministic process in the flaring state., Comment: 6 pages, 2 figures, 4 tables, proceeding to appear on EPJ Web of Conferences "The Innermost Regions of Relativistic Jets and their Magnetic Fields (Granada, Spain,10-14 June 2013)"

We present a set of photometric and spectroscopic observations of a bright Type Ib supernova SN 2012au from -6d until ~+150d after maximum. The shape of its early R-band light curve is similar to that of an average Type Ib/c supernova. The peak absolute magnitude is M_R=-18.7+-0.2 mag, which suggests that this supernova belongs to a very luminous group among Type Ib supernovae. The line velocity of He I {\lambda}5876 is about 15,000 km/s around maximum, which is much faster than that in a typical Type Ib supernova. From the quasi-bolometric peak luminosity of (6.7+-1.3)x10^(42) erg/s, we estimate the \Ni mass produced during the explosion as ~0.30 Msun. We also give a rough constraint to the ejecta mass 5-7 Msun and the kinetic energy (7-18)x10^(51) erg. We find a weak correlation between the peak absolute magnitude and He I velocity among Type Ib SNe. The similarities to SN 1998bw in the density structure inferred from the light curve model as well as the large peak bolometric luminosity suggest that SN 2012au had properties similar to energetic Type Ic supernovae., Comment: 15 pages, 5 figures; accepted to ApJL

We show that light sheet fluorescence microscopy with structured and pivoting illumination enables fast image acquisition and improved image quality. A one-dimensional spatial light phase modulator is used to control the illumination profile at high speed. To demonstrate the features of the system, we image fluorescent beads and biological samples, successfully obtaining optically sectioned images with higher contrast using structured illumination and with reduced shadowing effects using pivoting illumination.