282 research outputs found

    High Metallicity of the X-Ray Gas up to the Virial Radius of a Binary Cluster of Galaxies: Evidence of Galactic Superwinds at High-Redshift

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    We present an analysis of a Suzaku observation of the link region between the galaxy clusters A399 and A401. We obtained the metallicity of the intracluster medium (ICM) up to the cluster virial radii for the first time. We determine the metallicity where the virial radii of the two clusters cross each other (~2 Mpc away from their centers) and found that it is comparable to that in their inner regions (~0.2 Zsun). It is unlikely that the uniformity of metallicity up to the virial radii is due to mixing caused by a cluster collision. Since the ram-pressure is too small to strip the interstellar medium of galaxies around the virial radius of a cluster, the fairly high metallicity that we found there indicates that the metals in the ICM are not transported from member galaxies by ram-pressure stripping. Instead, the uniformity suggests that the proto-cluster region was extensively polluted with metals by extremely powerful outflows (superwinds) from galaxies before the clusters formed. We also searched for the oxygen emission from the warm--hot intergalactic medium in that region and obtained a strict upper limit of the hydrogen density (nH<4.1x10^-5 cm^-3).Comment: Typo corrected. The published version is available on-line free of charge by the end of 2008. http://pasj.asj.or.jp/v60/sp1/60s133/60s133.pd

    The Abudance Crown of Thorn Starfish (Acanthaster Planci) in Coral Reef Ecosystem Tikus Island Bengkulu Province

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    Penelitian ini dilaksanakan pada bulan Juni 2019 di Pulau Tikus Provinsi Bengkulu untuk mengetahui bagaimana kepadatan bintang laut berduri (A. planci), bagaimana kondisi terumbu karang serta bagaimana kepadatan bintang laut berduri (A. planci) pada ekosistem terumbu karang yang dianalisis berdasarkan tutupan karang hidup di Pulau Tikus. Metode yang digunakan adalah metode survey. Pengambilan data kondisi terumbu karang dilakukan menggunakan metode Underwater Photograph Transect (UPT) dan pengambilan data kepadatan A. planci menggunakan metode line Intercept Transect (LIT). Kondisi Terumbu karang Pulau Tikus Provinsi Bengkulu pada 3 stasiun penelitian kedalaman 4 meter didapatkan masuk dalam kategori sedang-bagus. Pada stasiun I didapatkan persentase tutupan 44,4% atau dalam kategori sedang, pada stasiun II didapatkan persentase tutupan 59,33% dan stasiun III didapatkan persentase tutupan 59,04% yang masuk dalam kategori baik. Sedangkan pada kedalaman 9 meter didapatkan persentase tutupan dalam kategori buruk yaitu 13,93-20,20%. Kepadatan A. planci pada 3 stasiun penelitian yang masing masing dilakukan pengambilan data pada kedalaman 4 dan 9 meter semuanya masih dalam status populasi normal atau alami dengan kepadatan tertinggi yaitu 0,004 ind/mĀ² sehingga belum memberikan ancaman yang berarti bagi ekosistem terumbu karang. Kepadatan A. planci pada masing masing stasiun penelitian juga tidak memperlihatkan perbedaan baik itu berdasarkan kedalaman maupun berdasarkan stasiun

    Searching for Diffuse Nonthermal X-Rays from the Superbubbles N11 and N51D in the Large Magellanic Cloud

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    We report on observations of the superbubbles (SBs) N11 and N51D in the Large Magellanic Cloud (LMC) with Suzaku and XMM-Newton. The interior of both SBs exhibits diffuse X-ray emission, which is well represented by thin thermal plasma models with a temperature of 0.2-0.3keV. The presence of nonthermal emission, claimed in previous works, is much less evident in our careful investigation. The 3-sigma upper limits of 2-10keV flux are 3.6*10^{-14}ergs/cm^2/s and 4.7*10^{-14}ergs/cm^2/s for N11 and N51D, respectively. The previous claims of the detection of nonthermal emission are probably due to the inaccurate estimation of the non X-ray background. We conclude that no credible nonthermal emission has been detected from the SBs in the LMC, with the exception of 30 Dor C.Comment: 9 pages, accepted for publication in ApJ

    X-ray Temperature and Mass Measurements to the Virial Radius of Abell 1413 with Suzaku

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    We present X-ray observations of the northern outskirts of the relaxed galaxy cluster A1413 with Suzaku, whose XIS instrument has the low intrinsic background needed to make measurements of these low surface brightness regions. We excise 15 point sources superimposed on the image above a flux of 1Ɨ10āˆ’141\times 10^{-14} \fluxunit (2--10keV) using XMM-Newton and Suzaku images of the cluster. We quantify all known systematic errors as part of our analysis, and show our statistical errors encompasses them for the most part. Our results extend previous measurements with Chandra and XMM-Newton, and show a significant temperature drop to about 3keV at the virial radius, r200r_{200}. Our entropy profile in the outer region (>0.5r200> 0.5 r_{200}) joins smoothly onto that of XMM-Newton, and shows a flatter slope compared with simple models, similar to a few other clusters observed at the virial radius. The integrated mass of the cluster at the virial radius is approximately 7.5Ɨ1014MāŠ™7.5\times10^{14}M_{\odot} and varies by about 30% depending on the particular method used to measure it.Comment: 32pages, 9 figures, accepted for publication in PAS

    Eco-aesthetic dimensions: Herbert Marcuse, ecollogy and art

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    In his last book, The Aesthetic Dimension (1978), Marcuse argued that a concern for aesthetics is justified when political change is unlikely. But the relation between aesthetics and politics is oblique: ā€œArt cannot change the world, but it can contribute to changing the consciousness ā€¦ of the men and women who could change the world.ā€ (p. 33). Marcuse also linked his critique of capitalism to environmentalism in the early 1970s: ā€œthe violation of the Earth is a vital aspect of the counterrevolution.ā€ (Ecology and Revolution, in The New Left and the 1960s, Collected Papers 3, 2005, p. 173). This article revisits Marcuseā€™s ideas on aesthetics and ecology, and reviews two recent art projects which engage their audiences in ecological issues: The Jetty Project (2014) by Wolfgang Weilederā€”which used recycled material and community participation to construct a temporary monument within a wider conservation project on the Tyne, N-E Englandā€”and Fracking Futures by HeHe (Helen Evans and Heiko Hansen)ā€”which turned the interior of the gallery at FACT, Liverpool, into what appeared to be a fracking site. The aim is not to evaluate the projects, nor to test the efficacy of Marcuseā€™s ideas, more to ask again whether art has a role in a shift of attitude which might contribute to dealing with the political and economic causes of climate change

    Suzaku measurement of Abell 2204's intracluster gas temperature profile out to 1800 kpc

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    Context: Measurements of intracluster gas temperatures out to large radii are important for the use of clusters for precision cosmology and for studies of cluster physics. Previous attempts to measure robust temperatures at cluster virial radii failed. Aims: The goal of this work is to measure the temperature profile of the very relaxed galaxy cluster Abell 2204 out to large radii, possibly reaching the virial radius. Methods: Taking advantage of its low particle background due to its low-Earth orbit, Suzaku data are used to measure the outer temperature profile of Abell 2204. These data are combined with Chandra and XMM-Newton data of the same cluster in order to make the connection to the inner regions, unresolved by Suzaku, and to determine the smearing due to Suzaku's PSF. Results: The temperature profile of Abell 2204 is determined from 10 kpc to 1800 kpc, close to an estimate of r200 (the approximation to the virial radius). The temperature rises steeply from below 4 keV in the very center up to more than 8 keV in the intermediate range and then decreases again to about 4 keV at the largest radii. Varying the measured particle background normalization artificially by +-10 percent does not change the results significantly. Predictions for outer temperature profiles based on hydrodynamic simulations show good agreement. In particular, we find the observed temperature profile to be slightly steeper but consistent with a drop of a factor of 0.6 from 0.3 r200 to r200, as predicted by simulations. Conclusions: Temperature measurements up to the virial radius seem feasible with Suzaku, when a careful analysis of the different background components and the effects of the PSF is performed. The result obtained here indicates that numerical simulations capture the intracluster gas physics well in cluster outskirts.Comment: 7 pages; Astronomy and Astrophysics, accepted; additional systematic effects have been quantified, results unchanged; also available at http://www.reiprich.ne

    Monte-Carlo Simulator and Ancillary Response Generator of Suzaku XRT/XIS System for Spatially Extended Source Analysis

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    We have developed a framework for the Monte-Carlo simulation of the X-Ray Telescopes (XRT) and the X-ray Imaging Spectrometers (XIS) onboard Suzaku, mainly for the scientific analysis of spatially and spectroscopically complex celestial sources. A photon-by-photon instrumental simulator is built on the ANL platform, which has been successfully used in ASCA data analysis. The simulator has a modular structure, in which the XRT simulation is based on a ray-tracing library, while the XIS simulation utilizes a spectral "Redistribution Matrix File" (RMF), generated separately by other tools. Instrumental characteristics and calibration results, e.g., XRT geometry, reflectivity, mutual alignments, thermal shield transmission, build-up of the contamination on the XIS optical blocking filters (OBF), are incorporated as completely as possible. Most of this information is available in the form of the FITS (Flexible Image Transport System) files in the standard calibration database (CALDB). This simulator can also be utilized to generate an "Ancillary Response File" (ARF), which describes the XRT response and the amount of OBF contamination. The ARF is dependent on the spatial distribution of the celestial target and the photon accumulation region on the detector, as well as observing conditions such as the observation date and satellite attitude. We describe principles of the simulator and the ARF generator, and demonstrate their performance in comparison with in-flight data.Comment: 19 pages with 8 figures, accepted for publication in PASJ Vol 58, Suzaku special issu

    Consilient Discrepancy: Porosity and Atmosphere in Cinema and Architecture

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    Cinema constitutes a way of looking at the world, at a world ā€“ its aspect, its appearance; but it also presents how that world looks, its prospect ā€“ by the prospective glance it throws back toward us. The ā€œlookā€ of a film ā€“ its mood, ambiance or atmosphere ā€“ eclipses formal and aesthetics registers. It is fundamentally world-forming, and therefore both cosmogonic and ethical: cosmogonic because it produces a world in the midst of, and as, the temporality that devolves through its passage; and ethical because the world it brings about is an inhabited world, a conjugation of people and place that constructs particular ways of being-there-together. The premise here is that atmosphere, ambiance and mood have never been vague categories for cinema and need not be for architecture: rather, that they are in fact producible through deliberate organizational strategies ā€“ kinematic and narrative in film, tectonic and material in architecture ā€“ according to what might be called ā€œconsilient discrepancyā€ ā€“ the coexistence of disseveral systems in unaligned multiplicity that, while never fusing, resonate to produce emergent conditions. Cinema offers architecture an accessible and instructive instance of such consilient discrepancy, because, in it, atmosphere is more fully captured and the conditions that create it more evidently analyzable. To that extent, cinema provides architecture with comparative grounds for engaging with atmosphere through a properly tectonic practice that can potentially enrich the design and experience of architecture. Consilient discrepancy is evident across multiple registers in film. It can function at the level of narrative, space and time and thus puts into question verisimilitude, causality, situational and durational veracity. An example of this is the constitutive disjunctions of Jean-Luc Godardā€™s jump cut montage where sampled film sequences, film and photographic stills, texts and citations, ambient sound, spoken word and music, build into complex assemblages of sense (Histoire(s) du Cinema, 1998). It is evident in Nicholas Roegā€™s multiple, simultaneous temporalities where past and future events interpenetrate and mutually condition the narrative present (Bad Timing, 1980). Similarly, we can find it in Michelangelo Antonioniā€™s sequence shots that traverse multiple timeframes across the same space ā€“ a technique that enables past and present to communicate and amplify the affective, foundational value of the unseen and off-frame (The Passenger, 1975). Another example would be David Lynchā€™s labyrinthine existential settings, constituted of interminable slippages between indeterminable and infinitely potentialized spaces of dreams, imagination, memory and reality (Mulholland Drive, 2001). Likewise, we could cite Michael Hanakeā€™s persistent displacement of causality and verisimilitude through ambiguous narrative viewpoints (CachĆ©, 2005), and Roy Anderssonā€™s radically liminal settings and characters whose lives constitute larval pre- and/or posthuman states of existence (A Pigeon Sat on a Branch Reflecting on Existence, 2014). This paper will foreground two foundational characteristics of atmosphere in cinema, as evident in the works just cited, and explore their applicability to architecture. The first characteristic is the consilient discrepancy outlined here by way of introduction, and the second, related characteristic, is a spatiality of porosity and occlusion. The provisional aim of comparing cinema and architecture according to this tectonic logic is to go beyond typical ways of understanding cinemaā€™s formal engagement with architecture. For this purpose, a detailed analysis of BĆ©la Tarrā€™s film Werckmeister Harmonies (2000) will serve as a case study for how the medium of cinema generates atmosphere, ambiance and mood through visual language. This will be followed by a similarly detailed consideration of concomitant qualities created in two recent works by the architects Flores Prats, the Mills Museum and Casal Balaguer. Functioning as exemplars of how cinematic qualities can be made manifest in architecture, these precedents will further substantiate the cinematicā€“architectonic proposition ventured in this paper

    The simple and rapid detection of specific PCR products from bacterial genomes using Zn finger proteins

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    A novel method of rapid and specific detection of polymerase chain reaction (PCR) products from bacterial genomes using Zn finger proteins was developed. Zn finger proteins are DNA-binding proteins that can sequence specifically recognize PCR products. Since Zn finger proteins can directly detect PCR products without undergoing dehybridization, unlike probe DNA, and can double check the specific PCR amplification and sequence specificity of the PCR products, this novel method would be quick and highly accurate. In this study, we tried to detect Legionella pneumophila using Sp1. It was found that a 49 bp L. pneumophila-specific region containing the Sp1 recognition site is located on the flhA gene of the L. pneumophila genome. We succeeded in specifically detecting PCR products amplified from L. pneumophila in the presence of other bacterial genomes by ELISA, and demonstrated that Sp1 enables the discrimination of L. pneumophila-specific PCR products from others. By fluorescence depolarization measurement, these specific PCR products could be detected within 1 min. These results indicate that the rapid and simple detection of PCR products specific to L. pneumophila using a Zn finger protein was achieved. This methodology can be applied to the detection of other bacteria using various Zn finger proteins that have already been reported
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