Suzaku X-Ray Observations of the Accreting NGC 4839 Group of Galaxies and the Radio Relic in the Coma Cluster

Based on Suzaku X-ray observations, we study the hot gas around the NGC4839 group of galaxies and the radio relic in the outskirts of the Coma cluster. We find a gradual decline in the gas temperature from 5 keV around NGC4839 to 3.6 keV at the radio relic, across which there is a further, steeper drop down to 1.5 keV. This drop as well as the observed surface brightness profile are consistent with a shock with Mach number M = 2.2 pm 0.5 and velocity vs = (1410 pm 110) km s^-1. A lower limit of B > 0.33 mu G is derived on the magnetic field strength around the relic from upper limits to inverse Compton X-ray emission. Although this suggests that the non-thermal electrons responsible for the relic are generated by diffusive shock acceleration (DSA), the relation between the measured Mach number and the electron spectrum inferred from radio observations are inconsistent with that expected from the simplest, test-particle theory of DSA. Nevertheless, DSA is still viable if it is initiated by the injection of a pre-existing population of non-thermal electrons. Combined with previous measurements, the temperature profile of Coma in the southwest direction is shallower outside NGC4839 and also slightly shallower in the outermost region. The metal abundance around NGC4839 is confirmed to be higher than in its vicinity, implying a significant peak in the abundance profile that decreases to 0.2 solar toward the outskirts. We interpret these facts as due to ram pressure stripping of metal-enriched gas from NGC4839 as it falls into Coma. The relic shock may result from the combined interaction of pre-existing intracluster gas, gas associated with NGC 4839, and cooler gas flowing in from the large-scale structure filament in the southwest.Comment: 13 page, accepted for publication in Publications of the Astronomical Society of Japa

Metallicity of the Fossil Group NGC 1550 Observed with Suzaku

We studied the temperature and metal abundance distributions of the intra-cluster medium (ICM) in a group of galaxies NGC 1550 observed with Suzaku. The NGC 1550 is classified as a fossil group, which have few bright member galaxies except for the central galaxy. Thus, such a type of galaxy is important to investigate how the metals are enriched to the ICM. With the Suzaku XIS instruments, we directly measured not only Si, S, and Fe lines but also O and Mg lines and obtained those abundances to an outer region of ~0.5 r_180 for the first time, and confirmed that the metals in the ICM of such a fossil group are indeed extending to a large radius. We found steeper gradients for Mg, Si, S, and Fe abundances, while O showed almost flat abundance distribution. Abundance ratios of alpha-elements to Fe were similar to those of the other groups and poor clusters. We calculated the number ratio of type II to type Ia supernovae for the ICM enrichment to be 2.9 +- 0.5 within 0.1 r_180, and the value was consistent with those for the other groups and poor clusters observed with Suzaku. We also calculated metal mass-to-light ratios (MLRs) for Fe, O and Mg with B-band and K-band luminosities of the member galaxies of NGC 1550. The derived MLRs were comparable to those of NGC 5044 group in the r<0.1 r_180 region, while those of NGC 1550 are slightly higher than those of NGC 5044 in the outer region.Comment: 11 pages, 7 figures, accepted for publication in PAS

Isolation and Characterization of Phthalic Acid Utilizing Bacteria

集積培養法によって土壌からフタル酸,イソ－およびテレ－フタル酸を唯一の炭素源として生育する14株が得られた。これらの菌株はフタル酸異性体の利用性の相違に基づき,7群に分けられた。このうちで,フタル酸に最も良く生育したNa3－31株を用いて実験を行なった。 フタル酸酸化活性の高い菌体を得るには,培地の窒素源は硝酸アンモニウムが良く,鉄イオン濃度はFeSO4・7H2Oとして0.5㎎/100ml程度が良かった。重金属により本菌株の生育およびフタル酸酸化活性が完全に阻害された。 本菌株のフタル酸代謝系は誘導的であり,培地中にフタル酸が無くなると,その代謝活性は急激に減少した。高活性の菌体を多量に得るには,集菌1時間前に0.05%程度のフタル酸を再添加して集菌すれば良い。 本菌株は生育基質として種々の芳香族化合物を利用したが,フタル酸生育菌体は,フタル酸,カテコールおよびその誘導体のみを利用した。プロトカテキン酸を利用できないので従来提示されているプロトカテキン酸を経る代謝系とは異なる経路で本菌株はフタル酸を代謝分解していると推測された。Fourteen strains capable of growing on phthalic acid, iso- and/or tere- phtalic acids as a sole carbon source respectively, were isolated from soil with enrichment culture method. Strain No. 3-31 with an ability to grow on phthalic acid abundantly was selected for further experiments. Ammonium nitrate and ferrous sulfate enhanced the production of cells with high phthalic acid oxidizing activity. Enzymes to metabolise phthalic acid in this strain was inducible. It was required to add 0.05 % phthalic acid before harvest to obtain the large amount of cells with high activity to oxidize phthalic acid. Since cells grown on phthalic acid could not oxidize protocatechuic acid, a new pathway to metabolise phthalic acid was estimated

A fundamental study assessing the generalized fitting method in conjunction with every possible coalition of N-combinations (G-EPOC) using the appendicitis detection task of computed tomography

Purpose: Increased use of deep learning (DL) in medical imaging diagnoses has led to more frequent use of 10-fold cross-validation (10-CV) for the evaluation of the performance of DL. To eliminate some of the (10-fold) repetitive processing in 10-CV, we proposed a "generalized fitting method in conjunction with every possible coalition of N-combinations (G-EPOC)", to estimate the range of the mean accuracy of 10-CV using less than 10 results of 10-CV. Material and methods: G-EPOC was executed as follows. We first provided (2N-1) coalition subsets using a specified N, which was 9 or less, out of 10 result datasets of 10-CV. We then obtained the estimation range of the accuracy by applying those subsets to the distribution fitting twice using a combination of normal, binominal, or Poisson distributions. Using datasets of 10-CVs acquired from the practical detection task of the appendicitis on CT by DL, we scored the estimation success rates if the range provided by G-EPOC included the true accuracy. Results: G-EPOC successfully estimated the range of the mean accuracy by 10-CV at over 95% rates for datasets with N assigned as 2 to 9. Conclusions: G-EPOC will help lessen the consumption of time and computer resources in the development of computer-based diagnoses in medical imaging and could become an option for the selection of a reasonable K value in K-CV

Formation of Nanometer-Thick Water Layer at High Humidity on Dynamic Crystalline Material Composed of Multi-Interactive Molecules

Crystalline powders self-assembled from interactive discrete molecules reversibly transformed from a porous structure to a 2D one with a nanometer-thick H2O layer by hydration/dehydration. Multi-point weak intermolecular interactions contributed to maintenance of each phase. This structure transformation induced a humidity-dependent ion conductivity change from insulator to 3.4 x 10(-3) S cm(-1).open1122sciescopu

Bayesian inference to identify crystalline structures for XRD

Crystalline phase structure is essential for understanding the performance and properties of a material. Therefore, this study identified and quantified the crystalline phase structure of a sample based on the diffraction pattern observed when the crystalline sample was irradiated with electromagnetic waves such as X-rays. Conventional analysis necessitates experienced and knowledgeable researchers to shorten the list from many candidate crystalline phase structures. However, the Conventional diffraction pattern analysis is highly analyst-dependent and not objective. Additionally, there is no established method for discussing the confidence intervals of the analysis results. Thus, this study aimed to establish a method for automatically inferring crystalline phase structures from diffraction patterns using Bayesian inference. Our method successfully identified true crystalline phase structures with a high probability from 50 candidate crystalline phase structures. Further, the mixing ratios of selected crystalline phase structures were estimated with a high degree of accuracy. This study provided reasonable results for well-crystallized samples that clearly identified the crystalline phase structures

Suzaku Observation of Group of Galaxies NGC 507: Temperature and Metal Distributions in the Intra-cluster Medium

Temperature and abundance distributions of the intra-cluster medium (ICM) in the NGC 507 group of galaxies were studied with Suzaku. Observed concentric annular spectra were well-represented by a two temperature model for ICM, and we found steeper abundance gradients for Mg, Si, S, and Fe compared with O in the central region. Abundance ratios of alpha-elements to iron were found to be similar to those in other groups and poor clusters. We calculated metal mass-to-light ratios for Fe, O and Mg (IMLR, OMLR, MMLR) for NGC 507, and values for different systems were compared. Hotter and richer systems tend to show higher values of IMLR, OMLR, and MMLR. OMLR and MMLR were measured to an outer region for the first time with Suzaku, while IMLR was consistent with that with ASCA. We also looked into 2-dimensional map of the hardness ratio, but found no significant deviation from the circular symmetry.Comment: 12 pages, 10 figures, accepted for publication in PAS

THERMAL AND CHEMICAL EVOLUTIONS OF GALAXY CLUSTERS OBSERVED WITH SUZAKU

We studied the properties of the intracluster medium (ICM) of galaxy clusters to outer regions observed with Suzaku. The observed temperature dropped by about ~30% from the central region to the virial radius of the clusters. The derived entropy profile agreed with the expectation from simulations within r500, while the entropy profile in r &gt; r500 indicated a flatter slope than the simulations. This would suggest that the cluster outskirts were out of hydrostatic equilibrium. As for the metallicity, we studied the metal abundances from O to Fe up to ~0.5 times the virial radius of galaxy groups and clusters. Comparing the results with supernova nucleosynthesis models, the number ratio of type II to Ia supernovae is estimated to be ~3.5. We also calculated not only Fe, but also O and Mg mass-to-light ratios (MLRs) with K-band luminosity. The MLRs in the clusters had a similar feature