Search

We present the gamma-ray, X-ray, optical and radio data for GRB100814A. At the end of the slow decline phase of the X-ray and optical afterglow, a sudden and prominent rebrightening in the optical band occurs followed by a fast decay in both bands. This optical rebrightening is accompanied by possible chromatic variations. We discuss possible interpretations, such as double component scenarios and internal dissipation mechanism, with their virtues and drawbacks. We also compare GRB100814A with other Swift bursts that show optical rebrightenings with similar properties.

We have studied the optical temporal evolution of 42 Swift GRBs. Our investigation shows that most of the optical properties can be interpreted by the external shock model and implies that the observed optical emission originated from this model. However, of the 42 GRBs, 10 show shallow decay properties in their overall optical light curve. Further investigations into the 10 GRBs found that the corresponding shallow decay properties were also found in their X-ray light curve. Apart from GRB 050730, our results also indicate that most shallow decay orginates from the external shock in both X-ray and optical. We conclude that, for some bursts, the optical and X-ray shallow decay have an extrnal origin, but some bursts have different emission mechanisms.

We present our successful program using Chandra for identifying the X-ray afterglow with sub-arcsecond accuracy for the short GRB 111117A d iscovered by Swift and Fermi. Thanks to our rapid target of opportuni ty request, Chandra clearly detected the X-ray afterglow, whereas no optical afterglow was found in deep optical observations. Instead, we clearly detect the host galaxy in optica; and also in near-infrared b ands. We found that the best photometric redshift fitofthe host is z = 1.31:(+0.46/-0.23) (90% confidence), making it one of the highest redshift short GRBs. Furthermore, we see an offset of 1.0+/-O.2 arcseco nds, which corresponds to 8.4+/-1.7 kpc aSBuming z= 1.31, between the host and the afterglow position. We discuss the importance of using Chandra for obtaining sub-arcsecond localization of the afterglow in X -rays for short GRBs to study GRB environments in great detail.

This study presents multi-wavelength observational results for energetic GRB100414A with GeV photons. The prompt spectral fitting using Suzaku/WAM data yielded spectral peak energies of E peak of 1458.7 +132.6 −106.6 keV and Eiso of 34.5 +2.0 −1.8 × 10 52 erg with z = 1.368. The optical afterglow light curves between 3 and 7 days were effectively fitted according to a simple power law with a temporal index of α = −2.6 ± 0.1. The joint light curve with earlier Swift/UVOT observations yields a temporal break at 2.3±0.2 days. This was the first Fermi /LAT detected event that demonstrated the clear temporal break in the optical afterglow. The jet opening angle derived from this temporal break was 5.8, consistent with those of other well-observed long gamma-ray bursts (GRBs). The multi-wavelength analyses in this study showed that GRB100414A follows E peak − Eiso and E src peak − Eγ correlations. The late afterglow revealed a flatter evolution with significant excesses at 27.2 days. The most straightforward explanation for the excess is that GRB100414A was accompanied by a contemporaneous supernova. The model light curve based on other GRB−SN events is marginally consistent with that of the observed lightcurve. Subject headings: Gamma-ray burst: individual

We present deep optical and X-ray follow-up observations of the bright unassociated Fermi-LAT gammaray source 1FGL J1311.7-3429. The source was already known as an unidentified EGRET source (3EG J1314-3431, EGR J1314-3417), hence its nature has remained uncertain for the past two decades. For the putative counterpart, we detected a quasi-sinusoidal optical modulation of delta_m\sim2 mag with a period of ~1.5 hr in the Rc, r' and g' bands. Moreover, we found that the amplitude of the modulation and peak intensity changed by > 1 mag and 0.5 mag respectively, over our total six nights of observations from 2012 March and May. Combined with Swif t UVOT data, the optical-UV spectrum is consistent with a blackbody temperature, kT \sim1 eV, and the emission volume radius Rbb\sim 1.5x10^4 km. In contrast, deep Suzaku observations conducted in 2009 and 2011 revealed strong X-ray flares with a lightcurve characterized with a power spectrum density of P(f) propto f^(-2) but the folded X-ray light curves suggest an orbital modulation also in X-rays. Together with the non-detection of a radio counterpart, and significant curved spectrum and non-detection of variability in gamma-rays, the source may be the second radio-quiet gamma-ray emitting milli-second pulsar candidate after 1FGL J2339.7-0531, although the origin of flaring X-ray and optical variability remains an open question., 8 pages, 10 figures, to appear in the Astrophysical Journal (ApJ)

We present the study on GRB 071112C X-ray and optical light curves. In these two wavelength ranges, we have found different temporal properties. The R-band light curve showed an initial rise followed by a single power-law decay, while the X-ray light curve was described by a single power-law decay plus a flare-like feature. Our analysis shows that the observed temporal evolution cannot be described by the external shock model in which the X-ray and optical emission are produced by the same emission mechanism. No significant color changes in multi-band light curves and a reasonable value of the initial Lorentz factor ({\Gamma}0 = 275 \pm 20) in a uniform ISM support the afterglow onset scenario as the correct interpretation for the early R-band rise. The result suggests the optical flux is dominated by afterglow. Our further investigations show that the X-ray flux could be created by an additional feature related to energy injection and X-ray afterglow. Different theoretical interpretations indicate the additional feature in X-ray can be explained by either late internal dissipation or local inverse-Compton scattering in the external shock., Comment: 20 pages, 3 figures, accepted for publication in ApJ

Recent searches by unbiased, wide-field surveys have uncovered a group of extremely luminous optical transients. The initial discoveries of SN 2005ap by the Texas Supernova Search and SCP-06F6 in a deep Hubble pencil beam survey were followed by the Palomar Transient Factory confirmation of host redshifts for other similar transients. The transients share the common properties of high optical luminosities (peak magnitudes ~ -21 to -23), blue colors, and a lack of H or He spectral features. The physical mechanism that produces the luminosity is uncertain, with suggestions ranging from jet-driven explosion to pulsational pair-instability. Here we report the most detailed photometric and spectral coverage of an ultra-bright transient (SN 2010gx) detected in the Pan-STARRS 1 sky survey. In common with other transients in this family, early-time spectra show a blue continuum, and prominent broad absorption lines of O II. However, about 25d after discovery, the spectra developed type Ic supernova features, showing the characteristic broad Fe II and Si II absorption lines. Detailed, post-maximum follow-up may show that all SN 2005ap and SCP-06F6 type transients are linked to supernovae Ic. This poses problems in understanding the physics of the explosions: there is no indication from late-time photometry that the luminosity is powered by 56Ni, the broad lightcurves suggest very large ejected masses, and the slow spectral evolution is quite different from typical Ic timescales. The nature of the progenitor stars and the origin of the luminosity are intriguing and open questions., 16 pages, 4 figures, 1 table. Accepted for publication in the Astrophysical Journal Letters on September 9

The WIDeField telescope for Gamma-ray burst Early Timing (WIDGET) is used for a fully automated, ultra-wide-field survey aimed at detecting the prompt optical emission associated with Gamma-ray Bursts (GRBs). WIDGET surveys the HETE-2 and Swift/BAT pointing directions covering a total field of view of 62 degree x 62 degree every 10 secounds using an unfiltered system. This monitoring survey allows exploration of the optical emission before the gamma-ray trigger. The unfiltered magnitude is well converted to the SDSS r' system at a 0.1 mag level. Since 2004, WIDGET has made a total of ten simultaneous and one pre-trigger GRB observations. The efficiency of synchronized observation with HETE-2 is four times better than that of Swift. There has been no bright optical emission similar to that from GRB 080319B. The statistical analysis implies that GRB080319B is a rare event. This paper summarizes the design and operation of the WIDGET system and the simultaneous GRB observations obtained with this instrument., Comment: 19 pages, 11 figures, Accepted to appear in PASJ

Classification of different kinds of space objects plays an important role in many astronomy areas Nowadays the classification process can possibly involve a huge amount of data It could take a long time for processing and demand many resources for computation and storage In addition, it may also take much effort to train a qualified expert who needs to have both the astronomy domain knowledge and the capability to manipulate the data This research intends to provide an efficient, scalable classification system for astronomy research We implement a dynamic classification framework and system using support vector machines (SVMs) The proposed system is based on a large-scale, distributed storage environment, on which scientists can design their analysis processes in a more abstract manner, instead of an awkward and time-consuming approach which searches and collects related subset of data from the huge data set The experimental results confirm that our system is scalable and efficient.

慢性腎不金のため透析を施行している症例で, 〓痒感を訴えている20例 (男6例, 女14例, 平均年齢58±13歳, 平均透析年数3.2±2.5年) に対し, テルフェナジン120mg/日分2を4週間投与し, 投与前後で〓痒感, IgEに関して検討した. 〓痒感は有意 (p

We present our optical observations of {\em Swift} GRB 070518 afterglow obtained at the 0.8-m Tsinghua University-National Astronomical Observatory of China telescope (TNT) at Xinglong Observatory. Our follow-up observations were performed from 512 sec after the burst trigger. With the upper limit of redshift $\sim$0.7, GRB 070518 is found to be an optically dim burst. The spectra indices $��_{ox}$ of optical to X-ray are slightly larger than 0.5, which implies the burst might be a dark burst. The extinction $A_{V}$ of the host galaxy is 3.2 mag inferred from the X-ray hydrogen column density with Galactic extinction law, and 0.3 mag with SMC extinction law. Also, it is similar to three other low-redshift optically dim bursts, which belong to XRR or XRF, and mid-term duration($T_{90}, 8 pages, 4 figures, MNRAS accepted

The Suzaku Wide‐band All‐sky Monitor (WAM) consists of 20 BGO anti‐coincidence scintillators for the Hard X‐ray Detector (HXD). The WAM has a wide field of view (FOV), about half of the whole sky, a large collecting area, 800 cm2, and broad‐band energy coverage from 50 to 5000 keV. Thus it has been designed to work as a gamma‐ray burst detector. For the three years since Suzaku launch in July 2005, the WAM has been working very well. About 500 GRBs have been detected through the end of 2008, corresponding to a detection rate of ∼140 GRBs per year. The current status of the WAM is presented in this paper.

We report the detection of early (60-230 s) optical emission of the gamma-ray burst afterglow of GRB 071010B. No significant correlation with the prompt γ-ray emission was found. Our high time resolution data combining with other measurements within 2 days after the burst indicate that GRB 071010B is composed of a weak early brightening (α ~ 0.6), probably caused by the peak frequency passing through the optical wavelengths, followed by a decay (α ~ − 0.51), attributed to continuous energy injection by patchy jets.

80歳, 女性。右乳頭周囲に生じた乳房Paget病。非定型的乳房切断術を施行時, Halstedリンパ節の腫大を認めた。病理組織学的に乾酪壊死を伴わない肉芽腫を認めた。肉芽腫は異物巨細胞を混じ, 胞体内にasteroid bodyが存在した。この肉芽腫の発生機序について腫瘍細胞のリン脂質が関与するという説があり, 脂肪染色を含む各種特殊染色を施行したが, 原因を明らかにすることができなかった。

The long, bright gamma-ray burst GRB 070125 was localized by the Interplanetary Network. We present light curves of the prompt gamma-ray emission as observed by Konus-WIND, RHESSI, Suzaku-WAM, and \textit{Swift}-BAT. We detail the results of joint spectral fits with Konus and RHESSI data. The burst shows moderate hard-to-soft evolution in its multi-peaked emission over a period of about one minute. The total burst fluence as observed by Konus is $1.79 \times 10^{-4}$ erg/cm$^2$ (20 keV--10 MeV). Using the spectroscopic redshift $z=1.548$, we find that the burst is consistent with the ``Amati'' $E_{peak,i}-E_{iso}$ correlation. Assuming a jet opening angle derived from broadband modeling of the burst afterglow, GRB 070125 is a significant outlier to the ``Ghirlanda'' $E_{peak,i}-E_\gamma$ correlation. Its collimation-corrected energy release $E_\gamma = 2.5 \times 10^{52}$ ergs is the largest yet observed., Comment: 25 pages, 6 figures; accepted for publication in ApJ. Improved spectral fits and energetics estimates

Aims. Understand the shape and implications of the multiband light curve of GRB 050408, an X-ray rich (XRR) burst. Methods. We present a multiband optical light curve, covering the time from the onset of the gamma-ray event to several months after, when we only detect the host galaxy. Together with X-ray, millimetre and radio observations we compile what, to our knowledge, is the most complete multiband coverage of an XRR burst afterglow to date. Results. The optical and X-ray light curve is characterised by an early flattening and an intense bump peaking around 6 days after the burst onset. We explain the former by an off-axis viewed jet, in agreement with the predictions made for XRR by some models, and the latter with an energy injection equivalent in intensity to the initial shock. The analysis of the spectral flux distribution reveals an extinction compatible with a low chemical enrichment surrounding the burst. Together with the detection of an underlying starburst host galaxy we can strengthen the link between XRR and classical long-duration bursts., 出版社版: http://www.aanda.org/index.php?option=article&access=doi&doi=10.1051/0004-6361:20066660

The wide‐band all‐sky monitor (WAM) onboard Suzaku has the largest effective area in 300–5000 keV, and thus very powerful to constrain the E peak and high energy tail of gamma‐ray burst prompt emission. Collaboration with GLAST will give us high‐quality data of gamma‐ray prompt emissions to probe and resolve the emission mechanism and central engine of gamma‐ray bursts. Here we report initial results of the WAM and address on the collaboration with GLAST.

We verified the off-axis jet model of X-ray flashes (XRFs) and examined a discovery of off-axis orphan gamma-ray burst (GRB) afterglows. The XRF sample was selected on the basis of the following three factors: (1) a constraint on the lower peak energy of the prompt spectrum , (2) redshift measurements, and (3) multicolor observations of an earlier (or brightening) phase. XRF 020903 was the only sample selected on the basis of these criteria. A complete optical multicolor afterglow light curve of XRF 020903 obtained from archived data and photometric results in the literature showed an achromatic brightening around 0.7 days. An off-axis jet model with a large observing angle (0.21 rad, which is twice the jet opening half-angle, ) can naturally describe the achromatic brightening and the prompt X-ray spectral properties. This result indicates the existence of off-axis orphan GRB afterglow light curves. Events with a larger viewing angle () could be discovered using an 8 m class telescope with wide-field imagers such as the Subaru Hyper-Suprime-Cam and the Large Synoptic Survey Telescope.

We revealed that the dwarf nova 1RXS J232953.9+062814 is an SU UMa-type system with a superhump period of 66.774+/-0.010 min. The short period strongly indicates that the orbital period of this object is below the period minimum of cataclysmic variables. The superhump period is 4.04+/-0.02 % longer than the photometric period during quiescence (64.184+/-0.003 min), which is probably associated with the orbital period. Although the standard evolutionary scenario of cataclysmic variables predicts lower mass-transfer rates in systems with shorter orbital periods, we revealed firm evidence of a relatively high mass-transfer rate from its large proper motion and bright apparent magnitude. Its proximity indicates that we have overlooked a number of objects in this new class. With the analogous system of V485 Cen, these objects establish the first subpopulation in hydrogen-rich cataclysmic variables below the period minimum., Comment: 5 pages, 2 figures, PASJ in press

We present multi-wavelength observations of a typical long duration GRB 120326A at $z=1.798$, including rapid observations using a submillimeter array (SMA), and a comprehensive monitoring in X-ray and optical. The SMA observation provided the fastest detection to date among seven submillimeter afterglows at 230 GHz. The prompt spectral analysis, using Swift and Suzaku yielded a spectral peak energy of $E^{\rm src}_{\rm peak}=107.8^{+15.3}_{-15.3}$ keV and equivalent isotropic energy of $E_{\rm iso}$ as $3.18^{+0.40}_{-0.32}\times 10^{52}$ erg. The temporal evolution and spectral properties in the optical were consistent with the standard forward shock synchrotron with jet collimation ($6^{\circ}.69\pm0^{\circ}.16$). The forward shock modeling using a 2D relativistic hydrodynamic jet simulation also determined the reasonable burst explosion and the synchrotron radiation parameters for the optical afterglow. The X-ray light curve showed no apparent jet break and the temporal decay index relation between the X-ray and optical ($\alpha{\rm o}-\alpha_{X}=-1.45\pm0.10$) indicated different radiation processes in the X-ray and optical. Introducing synchrotron self-inverse Compton radiation from reverse shock is a possible solution, and the detection and the slow decay of the afterglow in submillimeter supports that this is a plausible idea. The observed temporal evolution and spectral properties as well as forward shock modeling parameters, enabled to determine reasonable functions to describe the afterglow properties. Because half of events share similar properties in the X-ray and optical to the current event, GRB120326A will be a benchmarks with further rapid follow-ups, using submillimeter instruments such as SMA and ALMA., Comment: 25 pages, 7 figures, 2 tables, accepted for publication in ApJ

At high redshift, the universe was so young that core-collapse supernovae (SNe) are suspected to be the dominant source of dust production. However, some observations indicate that the dust production by SNe is an inefficient process, casting doubts on the existence of abundant SNe-dust in the early universe. Recently, Perley et al. (2010) reported that the afterglow of GRB 071025 - an unusually red GRB at z ~ 5 - shows evidence for the SNe-produced dust. Since this is perhaps the only high redshift GRB exhibiting compelling evidence for SNe-dust but the result could easily be affected by small systematics in photometry, we re-examined the extinction properties of GRB 071025 using our own optical/near-infrared data at a different epoch. In addition, we tested SNe-dust models with different progenitor masses and dust destruction efficiencies to constrain the dust formation mechanisms. By searching for the best-fit model of the afterglow spectral energy distribution, we confirm the previous claim that the dust in GRB 071025 is most likely to originate from SNe. We also find that the SNe-dust model of 13 or 25M_{\odot} without dust destruction fits the extinction property of GRB 071025 best, while pair-instability SNe (PISNe) models with a 170M_{\odot} progenitor poorly fit the data. Our results indicate that, at least in some systems at high redshift, SNe with intermediate masses within 10 - 30M_{\odot} were the main contributors for the dust enrichment, and the dust destruction effect due to reverse shock was negligible., 14 pages, 2 figures, Accepted for publication in ApJL

To the Editor.— The combination of genital and axillary Paget's disease seems to be extremely rare. We recently experienced two cases of genital Paget's disease with bilateral axillary involvement, and observed that the appearances of their axillary lesions changed daily. Report of Cases.—Case 1.— A 77-year-old man had itchy erythema on his penile foreskin and scrotum for about 4 years. Physical examination revealed several erythematous and depigmented macules measuring approximately 1 to 2 cm in diameter on his penis and scrotum. We also noted an ill-defined fingertip-sized irregular erythema on each axilla (Fig 1). After admission, we noticed that the clinical appearances of his axillary lesions changed daily: on our first examination the apparent erythematous lesions of his axillae became fainter and obscure. Case 2.— A 72-year-old man had a gradually enlarging erythema on his pubic skin for about 2 years. Physical examination revealed a 23 × 18-mm erythematous plaque on the pubic area and reticular hypopigmented macules around it. There also was an egg-sized illdefined faintly erythematous macule on each axilla (Fig 2, left). After admission, we also found that the clinical appearances of his axillary lesions changed day by day from erythematous plaques to

著者人数: 16名, Accepted: 2006-09-20, 資料番号: SA1000366000

We report here the discovery by the Intermediate Palomar Transient Factory (iPTF) of iPTF14yb, a luminous(Mr ≈ -27.8 mag), cosmological (redshift 1.9733), rapidly fading optical transient. We demonstrate, based onprobabilistic arguments and a comparison with the broader population, that iPTF14yb is the optical afterglow ofthe long-duration gamma-ray burst GRB 140226A. This marks the first unambiguous discovery of a GRBafterglow prior to (and thus entirely independent of) an associated high-energy trigger. We estimate the rate ofiPTF14yb-like sources (i.e., cosmologically distant relativistic explosions) based on iPTF observations, inferringan all-sky value of Rrel = 610 yr?1 (68% confidence interval of 1102000 yr?1). Our derived rate is consistent(within the large uncertainty) with the all-sky rate of on-axis GRBs derived by the Swift satellite. Finally, webriefly discuss the implications of the nondetection to date of bona fide orphan afterglows (i.e., those lackingdetectable high-energy emission) on GRB beaming and the degree of baryon loading in these relativistic jets. © 2015. The American Astronomical Society. All rights reserved.

The Suzaku Wide-band All-sky Monitor (WAM) consists of thick BGO anti-coincidence shields of the Hard X-ray Detectors (HXD). It views about half of the sky and has a geometrical area of 800 cm per side and an effective area of 400 cm, even at 1 MeV. Hence, the WAM can provide unique opportunities to detect high-energy emission from GRBs and solar flares in the sub-MeV to MeV range. The WAM has detected more than 400 GRBs and 100 solar flares since its launch. This paper describes the in-flight performance of the HXD/WAM during the initial two years of operations, including the in-flight energy response, spectral and timing capabilities, and in-orbit background.