Modified Slim-Disk Model Based on Radiation-Hydrodynamic Simulation Data: The Conflict Between Outflow and Photon Trapping

Photon trapping and outflow are two key physics associated with the supercritical accretion flow. We investigate the conflict between these two processes based on two-dimensional radiation-hydrodynamic (RHD) simulation data and construct a simplified (radially) one-dimensional model. Mass loss due to outflow, which is not considered in the slim-disk model, will reduce surface density of the flow, and if very significant, it will totally suppress photon trapping effects. If the photon trapping is very significant, conversely, outflow will be suppressed because radiation pressure force will be reduced. To see what actually occurs, we examine the RHD simulation data and evaluate the accretion rate and outflow rate as functions of radius. We find that the former monotonically decreases, while the latter increases, as the radius decreases. However, the former is kept constant at small radii, inside several Schwarzschild radii, since the outflow is suppressed by the photon trapping effects. To understand the conflict between the photon trapping and outflow in a simpler way, we model the radial distribution of the accretion rate from the simulation data and build up a new (radially) one-dimensional model, which is similar to the slim-disk model but incorporates the mass loss effects due to the outflow. We find that the surface density (and, hence, the optical depth) is much reduced even inside the trapping radius, compared with the case without outflow, whereas the effective temperature distribution hardly changes. That is, the emergent spectra do not sensitively depend on the amount of mass outflow. We conclude that the slim-disk approach is valid for interpreting observations, even if the outflow is taken into account.Comment: 15 pages, 5 figures, accepted for publication in PAS

ブラックホール周りの超エディントン噴出流の特性

京都大学0048新制・論文博士博士(理学)乙第12813号論理博第1539号新制||理||1577(附属図書館)31300(主査)教授 嶺重 慎, 准教授 前田 啓一, 教授 長田 哲也学位規則第4条第2項該当Doctor of ScienceKyoto UniversityDFA

Mapping of the 2018 Heavy Rain Disaster in the Southern Part of Hiroshima Prefecture

これまでに発生した土砂災害，洪水，地震，津波などの災害の様子を示した地図をディザスターマップ（災害記録地図）と呼ぶことを提案し，その一例として平成30年7月豪雨直後から行った災害を記録する活動内容を報告した。平成30年7月豪雨によって広島県南部では多数の斜面崩壊が発生し，甚大な被害が生じた。広島大学の調査団を中心に，豪雨直後からその後約1年半に渡り，災害の情報を整理し，被害の様子を記録するディザスターマップの作成を行ってきた。具体的には地理情報システム（GIS）を用いて斜面崩壊の発生状況を示す地図や，被災の様子を記録した写真を撮影位置に配置した地図の作成である。本稿ではこのようなディザスターマップの作成経緯や内容などの記述に加え，今後の防災教育などにおいてのこれらの地図の活用の可能性について予察的な考察を行った。本稿では，過去のすべての災禍を「古災害」（paleo-disaster）と呼ぶことを提案した。ディザスターマップの作成を含め，過去の災禍についてそれぞれの広がりや履歴が明らかにされる研究が進展することを期待したい。A massive disaster, including a large number of slope movements and the flooding of large rivers, was triggered by record-breaking torrential rain in July 2018 over a broad area of western Japan. Severe damage in the southern part of Hiroshima prefecture was mainly caused by the debris flow, with a total of 108 people reported killed or missing. The geographer group for “the Hiroshima University Disaster Investigation Team for July Torrential Rain of 2018” recorded the distribution of slope movements as geographical data and prepared detailed maps on the geographic information system (GIS) since just after its initiation. The authors also created “disaster maps” with photographs of locations of slope movements, broken artificial features, and floods taken in the field were depicted in Higashihiroshima City, where the largest number of slope movements occurred in Hiroshima prefecture. In this paper, we described the process of making these maps and their contents, and the possibility of utilizing them for disaster prevention education. We also proposed referring to all past disasters as “paleo-disaster” to progress the research that reveals the distribution and history of past disasters

Two separate tyrosine protein kinases in human platelets

AbstractTyrosine protein kinase activities were detected in the cytosolic fraction (PC-TPK) and the particulate fraction (PM-TPK) in human platelets using the synthetic peptide, E11G1, (Glu-Asp-Ala-Glu-Tyr-Ala-Ala-Arg-Arg-Arg-Gly) as a substrate. PC-TPK and PM-TPK were different in substrate specificities, divalent cation requirements and apparent Mr values. These results strongly suggest that in platelets there exist at least two separate tyrosine protein kinases; one is present in cytosol and the other might be associated with membranes

Thermal Control System to Easily Cool the GAPS Balloon-borne Instrument on the Ground

This study developed a novel thermal control system to cool detectors of the General AntiParticle Spectrometer (GAPS) before its flights. GAPS is a balloon-borne cosmic-ray observation experiment. In its payload, GAPS contains over 1000 silicon detectors that must be cooled below -40^{\circ}\mbox{C}. All detectors are thermally coupled to a unique heat-pipe system (HPS) that transfers heat from the detectors to a radiator. The radiator is designed to be cooled below -50^{\circ}\mbox{C} during the flight by exposure to space. The pre-flight state of the detectors is checked on the ground at 1 atm and ambient room temperature, but the radiator cannot be similarly cooled. The authors have developed a ground cooling system (GCS) to chill the detectors for ground testing. The GCS consists of a cold plate, a chiller, and insulating foam. The cold plate is designed to be attached to the radiator and cooled by a coolant pumped by the chiller. The payload configuration, including the HPS, can be the same as that of the flight. The GCS design was validated by thermal tests using a scale model. The GCS design is simple and provides a practical guideline, including a simple estimation of appropriate thermal insulation thickness, which can be easily adapted to other applications.Comment: 8 pages, 14 figures, 3 table

PNLH related to Aspergillus infection

Aspergillus nodules (AN) are an unusual form of chronic pulmonary aspergillosis. On the other hand, pulmonary nodular lymphoid hyperplasia (PNLH) is classified as a reactive pulmonary lymphoproliferative disorder. A 65-year-old male was referred to our hospital due to a nodule in the left upper lobe. Histologically, a mixture of prominent lymphoid follicular formation, and hyaline necrosis were observed. Grocott staining revealed morphological forms of Aspergillus spp. in the necrosis. The final clinical diagnosis was suspected AN histologically consistent with PNLH. This case suggests that there may be PNLH cases in which local infection with Aspergillus contributes to its pathophysiology