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During a winter thunderstorm on 6 February 2017 in Japan, photonuclear reactions such as 14N(γ, n)13N were triggered by a downward terrestrial gamma‐ray flash (TGF), as reported by Enoto et al. (2017, https://doi.org/10.1038/nature24630). In the present paper, we compare the observation with a simulation model of downward TGFs and subsequent photonuclear reactions constructed by the first paper of the series and Wada, Enoto, Nakazawa, et al. (2019, https://doi.org/10.1103/physrevlett.123.061103). The observation and model consist of three components: annihilation gamma rays from positrons produced by β+‐decay nuclei, deexcitation gamma rays originating from neutron captures, and radiation doses by TGF photons. Each component of the observation is reproduced by the simulation model, and we constrain a relation between the number of avalanche electrons and their production altitude of the downward TGF. The constraints by three components match within an order of magnitude. The downward TGF is estimated to comprise (0.5–2.5) × 1019 avalanche electrons above 1 MeV produced at an altitude of 1.4–2.7 km. Despite differences in altitude, direction, and season, downward TGFs in winter thunderstorms are thought to have the same mechanism of electron acceleration and multiplication in lightning as TGFs observed by in‐orbit satellites. Plain Language Summary: Lightning flashes are sometimes accompanied by strong high‐energy emission called "terrestrial gamma‐ray flashes" (TGFs). The energy of gamma rays in TGFs is high enough to trigger nuclear reactions with atmospheric nuclei such as nitrogen and oxygen. The nuclear reactions produce neutrons and unstable isotopes that emit positrons. In the companion paper of this series, we calculated the nuclear reactions and propagation processes of their products such as positrons and neutrons and modeled their characteristics at ground level by simulations. In the present paper, the simulation model is compared with the actual observation of a TGF and nuclear reactions during winter thunderstorms in Japan. The model successfully reproduces the observation and estimate the production altitude the number of energetic electrons involved in the TGF. Key Points: A simulation model of photonuclear reactions in lightning is compared with an observation during a winter thunderstorm reported by Enoto et al. (2017, https://doi.org/10.1038/nature24630)Three detected signatures originating from positrons, neutrons, and TGF photons are reproduced by the simulation modelA downward TGF triggering photonuclear reactions comprised 1018 to 1019 avalanche electrons produced at 1.4–2.7 km above sea level [ABSTRACT FROM AUTHOR]

During 2017–2018 winter operation of the Gamma‐Ray Observation of Winter Thunderclouds experiment in Japan, two downward terrestrial gamma‐ray flashes (TGFs) that triggered atmospheric photonuclear reactions were detected. They took place during winter thunderstorms on 5 December 2017 and 9 January 2018 at Kanazawa, Ishikawa Prefecture, Japan. Each event coincided with an intracloud/intercloud discharge, which had a negative‐polarity peak current higher than 150 kA. Their radio waveforms in the low‐frequency band are categorized as a distinct lightning type called "energetic in‐cloud pulse" (EIP). Negative‐polarity EIPs have been previously suggested to be highly associated with downward TGFs, and the present observations provide evidence of the correlation between them for the first time. Furthermore, both of the downward TGFs followed "gamma‐ray glows," minute‐lasting high‐energy emissions from thunderclouds. It is suggested that the negative EIPs took place with downward propagating negative leaders or upward positive ones developed in highly electrified regions responsible for the gamma‐ray glows. Plain Language Summary: We observed, on the ground, intense and brief gamma‐ray emissions, called "downward terrestrial gamma‐ray flashes," twice during winter thunderstorms in Japan. They coincided with a kind of in‐cloud lightning discharges called "negative energetic in‐cloud pulses." They have been previously predicted to have a connection to downward terrestrial gamma‐ray flashes, and we observationally confirm the prediction for the first time. Furthermore, the two downward terrestrial gamma‐ray flashes were preceded by weak and minute‐lasting gamma‐ray emissions coming from thunderclouds, called "gamma‐ray glows." High electric fields inside thunderclouds required to produce gamma‐ray glows were thus related to the downward terrestrial gamma‐ray flashes and the negative energetic in‐cloud pulses. Key Points: Two downward terrestrial gamma‐ray flashes detected in Japan were coincident with high peak‐current lightning dischargesThe lightning discharges can be categorized as negative energetic in‐cloud pulsesBoth cases took place in highly electrified regions responsible for production of gamma‐ray glows [ABSTRACT FROM AUTHOR]

B Background: b Emerging evidence suggests the prognostic impact of the tumor microenvironment (TME) in peripheral T-cell lymphomas (PTCLs). THE GENETIC SUBTYPES AND THE TUMOR MICROENVIRONMENT SIGNATURES ARE ASSOCIATED WITH DISTINCT OUTCOMES IN PERIPHERAL T-CELL LYMPHOMA Ninety-two nTFHLs included 85 angioimmunoblastic T-cell lymphomas (AITLs), four nPTCL with TFH phenotypes, two follicular T-cell lymphomas, and one unclassifiable nTFHL. [Extracted from the article]

Using archival data from Suzaku, XMM–Newton , and NuSTAR , nine representative ultra-luminous X-ray sources (ULXs) in nearby galaxies were studied. Their X-ray spectra were all reproduced with a multicolour disc emission model plus its Comptonization. However, the spectral shapes of individual sources changed systematically depending on the luminosity, and defined three typical spectral states. These states differ either in the ratio between the Comptonizing electron temperature and the innermost disc temperature, or in the product of Compton y-parameter and fraction of the Comptonized disc photons. The luminosity range at which a particular state emerges was found to scatter by a factor of up to 16 among the eight ULXs. By further assuming that the spectral state is uniquely determined by the Eddington ratio, the sample ULXs are inferred to exhibit a similar scatter in their masses. This gives a model-independent support to the interpretation of ULXs in terms of relatively massive black holes. None of the spectra showed noticeable local structures. Especially, no Fe K-shell absorption/emission lines were detected, with upper limits of 30–40 eV in equivalent width from the brightest three among the sample: NGC 1313 X-1, Holmberg IX X-1, and IC 342 X-1. These properties disfavour ordinary mass accretion from a massive companion star, and suggest direct Bondi–Hoyle accretion from dense parts of the interstellar medium. [ABSTRACT FROM AUTHOR]

Abstract: An on‐ground observation program for high‐energy atmospheric phenomena in winter thunderstorms along the Japan Sea has been performed via measurements of gamma ray radiation, atmospheric electric field, and low‐frequency radio band. On 11 February 2017, the radiation detectors recorded gamma ray emission lasting for 75 s, and then abruptly terminated with a nearby lightning discharge. The gamma ray spectrum extended up to 20 MeV and was reproduced by a cutoff power law model with a photon index of 1 . 3 6 − 0 . 04 + 0 . 03, being consistent with Bremsstrahlung radiation from a thundercloud (known as a gamma‐ray glow or a thunderstorm ground enhancement). The low‐frequency radio monitors, installed ∼50 km away from the gamma ray observation site recorded leader development of an intracloud/intercloud discharge spreading over ∼60 km area with a ∼300‐ms duration. The timing of the gamma ray termination coincided with the moment when the leader development of the intracloud/intercloud discharge passed 0.7 km horizontally away from the radiation monitors. The intracloud/intercloud discharge started ∼15 km away from the gamma ray observation site. Therefore, the glow was terminated by the leader development, while it did not trigger the lightning discharge in the present case. [ABSTRACT FROM AUTHOR]

Attempts were made to construct a unified description of the spectra of ULX (Ultra Luminous X-ray source) objects, including their power-law (PL) state and disk-like state. Among spectral models proposed to explain either state, the present work adopts the one which combines multi-color disk (MCD) emission and its thermal Comptonization (THC). This model was applied to several datasets of ULXs obtained by Suzaku, XMM- Newton, and Nustar. The model well explains all the spectra, regardless of the spectral states, in terms of a cool disk ( Tin = 0.2-0.5 keV) and a cool thick ( Te = 1-3 keV, τ ∼ 10) corona. The fit results can be characterized by two new parameters. One is Q ≡ Te/ Tin which describes the balance between the Compton cooling and gravitational heating of the coronal electrons, while the other is F ≡ 1 - Fdirect/ Ftotal, namely, the covering fraction of the MCD by the corona. Here [ABSTRACT FROM AUTHOR]

The stellar wind around a compact object in luminous wind-accreting high-mass X-ray binaries is expected to be strongly ionized with the X-rays coming from the compact object. The stellar wind of hot stars is mostly driven by light absorption in lines of heavier elements, and X-ray photo-ionization significantly reduces the radiative force within the so-called Strömgren region, leading to wind stagnation around the compact object. In close binaries like Vela X-1 this effect might alter the wind structure throughout the system. Using the spectral data from the Monitor of All-sky X-ray Image (MAXI), we studied the observed dependence of the photoelectric absorption as a function of the orbital phase in Vela X-1 and found that it is inconsistent with expectations for a spherically symmetric smooth wind. Taking into account previous investigations, we developed a simple model for wind structure with a stream-like photoionization wake region of slower and denser wind trailing the neutron star, which is responsible for the observed absorption curve. [ABSTRACT FROM AUTHOR]

Based on optical and X-ray data for a sample of 34 relaxed rich clusters with redshift of 0.1-0.9, we studied the relative spatial distribution of the two major baryon contents, the cluster galaxies and the hot plasmas. Using photometric data taken with the UH88 telescope, we determined the integrated radial light profiles of member galaxies in each cluster using two independent approaches, i.e., the field background subtraction and the color-magnitude filtering. The ICM mass profile of each cluster in our sample was derived from a spatially-resolved spectral analysis using XMM- Newton and Chandra data. When the sample is divided into three subsamples with redshift intervals of z = 0.11-0.22, 0.22-0.45, and 0.45- 0.89, the galaxy light vs. ICM mass ratio profiles for the central 0.65 R500 regions were found to steepen from the higher- to lower- redshift subsamples, meaning that the galaxies become more concentrated in the ICM sphere towards lower redshifts. Besides, the galaxy light vs. total mass ratio profiles also exhibit gradual concentration towards lower redshift. We interpret that the galaxies, the ICM, and the dark matter components followed a similar spatial distribution in the early phase ( z > 0.5), while the galaxies have fallen towards the center relative to the ICM and dark matter. Such galaxy infall is likely tobe caused by ICM drag when galaxies move through the ICM, even though the dynamical friction can enhance the infall of the most massive galaxies. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

ABSTRACT In 2009 January, the 2.1-s anomalous X-ray pulsar 1E 1547.0−5408 evoked intense burst activity. A follow-up Suzaku observation on January 28 recorded enhanced persistent emission in both soft and hard X-rays. Through a reanalysis of the same Suzaku data, 18 short bursts were identified in the X-ray events recorded by the Hard X-ray Detector (HXD) and the X-ray Imaging Spectrometer (XIS). Their spectral peaks appear in the HXD-PIN band, and their 10-70 keV X-ray fluences range from ∼2 × 10−9 to 10−7 erg cm−2. Thus, the 18 events define a significantly weaker burst sample than has ever been obtained previously, ∼10−8-10−4 erg cm−2. In the ∼0.8 to ∼300 keV band, the spectra of the three brightest bursts can be represented successfully by a two-blackbody model, or a few alternative models. A spectrum that is constructed by stacking 13 weaker short bursts with fluences in the range (0.2-2) × 10−8 erg s−1 is less curved, and its ratio to the persistent emission spectrum becomes constant at ∼170 above ∼8 keV. As a result, the two-blackbody model was able to reproduce the stacked weaker-burst spectrum only after adding a power-law model, for which the photon index is fixed at 1.54 as measured by the persistent spectrum. These results imply that there is a possibility that the spectrum composition that employs an optically thick component and a hard power-law component can describe the wide-band spectra of both the persistent and weak-burst emissions, despite the fact that their fluxes differ by two orders of magnitude. Based on the spectral similarity, we discuss a possible connection between the unresolved short bursts and the persistent emission. [ABSTRACT FROM AUTHOR]

Gas electron multipliers with a liquid crystal polymer insulator (LCP-GEMs) can be employed as X-ray polarimeters in several satellite missions in low-earth orbit. To evaluate their resistance to radiation, LCP-GEMs were exposed to Fe ion and proton beams from the heavy-ion accelerator facility HIMAC, and the gas gain was monitored. The LCP-GEMs survived 14.4-year-equivalent irradiation by fully stripped Fe ions with an energy of 500 MeV\ nuc^-1, which simulated galactic cosmic-ray ions. We also studied the degradation of the insulator layer of the LCP-GEMs by irradiation with 160 MeV protons to simulate geomagnetically trapped protons. After irradiation with protons for 31.6 years equivalent, no significant change in gain was observed. [ABSTRACT FROM AUTHOR]

ABSTRACT SGR 1833−0832 was discovered on 2010 March 19, thanks to the Swift detection of a short hard X-ray burst and follow-up X-ray observations. Since then, it was repeatedly observed with Swift, Rossi X-ray Timing Explorer and XMM-Newton. Using these data, which span about 225 d, we studied the long-term spectral and timing characteristics of SGR 1833−0832. We found evidence for diffuse emission surrounding SGR 1833−0832, which is most likely a halo produced by the scattering of the point-source X-ray radiation by dust along the line of sight, and we show that the source X-ray spectrum is well described by an absorbed blackbody, with temperature kT∼ 1.2 keV and absorbing column NH= (10.4 ± 0.2) × 1022 cm−2, while different or more complex models are disfavoured. The source persistent X-ray emission remained fairly constant at ∼3.7 × 10−12 erg cm−2 s−1 for the first ∼20 d after the onset of the bursting episode, then it faded by a factor of ∼40 in the subsequent ∼140 d, following a power-law trend with index α≃−0.5. We obtained a phase-coherent timing solution with the longest baseline (∼225 d) to date for this source which, besides period P= 7.565 4084(4) s and period derivative s s−1, includes higher order period derivatives. We also report on our search of the counterpart to the soft gamma-ray repeater (SGR) at radio frequencies using the Australia Telescope Compact Array and the Parkes Radio Telescope. No evidence for radio emission was found, down to flux densities of 0.9 mJy (at 1.5 GHz) and 0.09 mJy (at 1.4 GHz) for the continuum and pulsed emissions, respectively, consistently with other observations at different epochs. Finally, the analysis of the field of PSR B1830−08 (J1833−0827), which was serendipitously imaged by the XMM-Newton observations, led to the discovery of the X-ray pulsar wind nebula generated by this 85-ms radio pulsar. We discuss its possible association with the unidentified TeV source HESS J1834−087. [ABSTRACT FROM AUTHOR]

A rapid timing analysis of Very Large Telescope (VLT)/ULTRACAM (optical) and RXTE (X-ray) observations of the Galactic black hole binary GX 4 in the low/hard, post-outburst state of 2007 June is presented. The optical light curves in the and u′ filters show slow (∼20 s) quasi-periodic variability. Upon this is superposed fast flaring activity on times approaching the best time resolution probed (∼50 ms in r′ and g′) and with maximum strengths of more than twice the local mean. Power spectral analysis over ∼0.004–10 Hz is presented, and shows that although the average optical variability amplitude is lower than that in X-rays, the peak variability power emerges at a higher Fourier frequency in the optical. Energetically, we measure a large optical versus X-ray flux ratio, higher than that seen on previous occasions when the source was fully jet dominated. Such a large ratio cannot be easily explained with a disc alone. Studying the optical–X-ray cross-spectrum in Fourier space shows a markedly different behaviour above and below ∼0.2 Hz. The peak of the coherence function above this threshold is associated with a short optical time lag with respect to X-rays, also seen as the dominant feature in the time-domain cross-correlation at ≈150 ms. The rms energy spectrum of these fast variations is best described by distinct physical components over the optical and X-ray regimes, and also suggests a maximal irradiated disc fraction of 20 per cent around 5000 Å. If the constant time delay is due to propagation of fluctuations to (or within) the jet, this is the clearest optical evidence to date of the location of this component. The low-frequency quasi-periodic oscillation is seen in the optical but not in X-rays, and is associated with a low coherence. Evidence of reprocessing emerges at the lowest Fourier frequencies, with optical lags at ∼10 s and strong coherence in the blue u′ filter. Consistent with this, simultaneous optical spectroscopy also shows the Bowen fluorescence blend, though its emission location is unclear. However, canonical disc reprocessing cannot dominate the optical power easily, nor explain the fast variability. [ABSTRACT FROM AUTHOR]

We present the discovery of optical/X-ray flux correlations on rapid time-scales in the low/hard state of the Galactic black hole GX 339−4. The source had recently emerged from outburst and was associated with a relatively faint counterpart with mag 17. The optical [Very Large Telescope (VLT)/ULTRACAM] and X-ray ( Rossi X-ray Timing Explorer) data show a clear positive cross-correlation function (CCF) signal, with the optical peak lagging X-rays by ∼150 ms, preceded by a shallow rise and followed by a steep decline along with broad anticorrelation dips. An examination of the light curves shows that the main CCF features are reproduced in superpositions of flares and dips. The CCF peak is narrow and the X-ray autocorrelation function (ACF) is broader than the optical ACF, arguing against reprocessing as the origin for the rapid optical emission. X-ray flaring is associated with spectral hardening, but no corresponding changes are detected around optical peaks and dips. The variability may be explained in the context of synchrotron emission with interaction between a jet and a corona. The complex CCF structure in GX 339−4 has similarities to that of another remarkable X-ray binary XTE J1118+480, in spite of showing a weaker maximum strength. Such simultaneous multiwavelength, rapid timing studies provide key constraints for modelling the inner regions of accreting stellar sources. [ABSTRACT FROM AUTHOR]

We have observed the X-ray brightest planetary nebula BD +30° 3639 with the new Japanese astronomical satellite Suzaku. With its superior spectral resolution back-illuminated CCD camera, a blend of K-lines from highly ionized C, N, O elements are successfully resolved into individual species, and an extremely high relative abundance ratio of C/O $\sim$ 40 is obtained. This strongly suggests the direct measurement of the helium shell-burning products. [ABSTRACT FROM PUBLISHER]

The soft gamma-ray detector (SGD) onboard the Japanese future high energy astrophysics mission (NeXT) is a Compton telescope with narrow field of view, which utilizes Compton kinematics to enhance its background rejection capabilities. It is realized as a hybrid semiconductor gamma-ray detector which consists of silicon and cadmium telluride (CdTe) detectors. It can detect photons in a wide energy band (0.05-1 MeV) at a background level of 5 times10-7 counts/s/cm2/keV; the silicon layers are required to improve the performance at a lower energy band (<0.3 MeV). Excellent energy resolution is the key feature of the SGD, allowing it to achieve both high angular resolution and good background rejection capability. An additional capability of the SGD, its ability to measure gamma-ray polarization, opens up a new window to study properties of astronomical objects. We will present the development of key technologies to realize the SGD: high quality CdTe, low noise front-end application-specific integrated circuit, and bump bonding technology. Energy resolutions of 1.7 keV (full-width at half-maximum) for CdTe pixel detectors and 1.1 keV for Si strip detectors have been measured. We also present the validation of Monte Carlo simulation used to evaluate the performance of the SGD [ABSTRACT FROM PUBLISHER]

We summarize significant improvements which have been achived in the development of Astro-E2 Hard Xray Detector (HXD-II). An expanded energy range and better energy resolution have been achieved from progresses in device materials and redesigning ot the front-end electronics. An improved estimation for the detector background in orbit has also been conducted based upon results from our proton irradiation experiment. The sensitivity of HXD-II can be expected to reach an order of 10-6 [cs-1 keV-1 cm-2]. [ABSTRACT FROM AUTHOR]