• 제목/요약/키워드: ALMA

검색결과 121건 처리시간 0.028초

Astrochem 코드를 활용한 천체에서의 화학반응

  • 양승원;곽규진
    • 천문학회보
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    • 제40권1호
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    • pp.81.4-82
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    • 2015
  • ALMA(Atacama Large Millimeter/submillimeter Array)의 고분해능 분광관측을 통해 천체에 존재하는 분자에 관한 다양한 정보를 얻을 수 있었고, 이러한 분자들을 형성하는 화학적 반응 메커니즘을 이해하는 것이 천체 현상을 이해하는 데 중요한 부분을 차지하게 되었다. 이러한 노력의 일환으로, 천체에서의 화학반응을 연구하기 위한 몇몇 코드가 개발되었는데 그중에 대표적인 것이 Astrochem 코드이다. 이 코드는 천체에 존재 할 수 있는 화학물질들의 분포변화를 시간에 따른 함수로 계산하는데, 이를위해 다양한 분자들을 형성하는 것으로 알려진 화학반응 데이터베이스인 KIDA, OSU를 활용한다. 이번 포스터에서는 Astrochem 코드를 이용해 얻을 수 있는 결과인 비교적 간단한 분자들의 시간에 따른 분포 변화를 발표한다. 향후 연구 방향은 유체역학 코드와 Astrochem 코드를 결합한 유체-천체화학 코드를 개발하는 것이며 이를 활용해 유체역학 현상이 다양한 분자들의 분포 변화에 어떠한 영향을 미치는지를 연구할 것이다. 이를 통해 보다 정확하게 천체 현상들을 예측 및 재현 가능할 것으로 기대된다.

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DUST-OBSCURED RADIO AGNS FROM THE WISE SURVEY

  • Kim, Minjin;Lonsdale, Carol J.;Lacy, Mark;Kimball, Amy;Condon, Jim
    • 천문학논총
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    • 제27권4호
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    • pp.289-290
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    • 2012
  • Feedback from accreting BH (AGN) is thought to be responsible for the co-evolution of BHs and galaxies. It is likely to be prominent in the most luminous dust-obscured quasars, particularly those containing radio sources too luminous to be powered by starbursts. In order to investigate the feedback mechanism in detail, we select a unique sample containing ~ 200 of the most luminous obscured QSOs by cross-matching the WISE catalog with the FIRST and NVSS radio surveys. We present overall statistics for the observed range of colors and radio/mid-IR flux density ratio. We also present our efforts to understand the physical and evolutionary nature of these extreme feedback candidates using various telescopes such as Magellan, SOAR, Herschel, and ALMA.

Critical thrust force and feed rate determination in drilling of GFRP laminate with backup plate

  • Heidary, Hossein;Mehrpouya, Mohammad A.;Saghafi, Hamed;Minak, Giangiacomo
    • Structural Engineering and Mechanics
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    • 제73권6호
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    • pp.631-640
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    • 2020
  • Using backup plate is one of the most commonly used methods to decrease drilling-induced delamination of composite laminates. It has been shown that, the size of the delamination zone is related to the vertical element of cutting force named as thrust force. Also, direct control of thrust force is not a routine task, because, it depends on both drilling parameters and mechanical properties of the composite laminate. In this research, critical feed rate and thrust force are predicted analytically for delamination initiation in drilling of composite laminates with backup plate. Three common theories, linear elastic fracture mechanics, classical laminated plate and mechanics of oblique cutting, are used to model the problem. Based on the proposed analytical model, the effect of drill radius, chisel edge size, and backup plate size on the critical thrust force and feed rate are investigated. Experimental tests were carried out to prove analytical model.

SUBARU EXPLORATIONS OF EXO-SOLAR PLANETS AND DISKS

  • TAMURA MOTOHIDE
    • 천문학회지
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    • 제38권2호
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    • pp.319-324
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    • 2005
  • To date, more than 150 exo-solar planets have been observed by various methods such as spectroscopic, photometric, astrometric, gravitational lensing, pulsar timing methods. However, all these are indirect methods; they do not directly image the planets. Only free-floating planets or their 'ana-log' have been directly detected so far. Thus the next milestone is the direct imaging of any kinds of planetary mass objects orbiting around normal (young) stars, which might have been associated with protoplanetary disks, the sites of planet formation. I will describe some SUBARU efforts to detect self-luminous young giant planets as companions as well as direct imaging of the protoplanetary disks of ${\~}$100 AU size. The results of near-infrared coronagraphic imaging with adaptive optics are briefly presented on AB Aur, HD 142527, T Tau, and DH Tau. Our results demonstrate the importance of high-resolution (${\~}$0.1 arcsec) direct imaging over indirect observations such as modeling based on spectral energy distributions. The SUBARU observations are a prelude to ALMA from the morphological point of view.

The Development of the East Asian Observatory

  • Ho, Paul
    • 천문학회보
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    • 제40권2호
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    • pp.27.3-27.3
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    • 2015
  • The East Asian Observatory (EAO) was established in 2014 by the East Asian Core Observatories Association (EACOA). The goal of the EAO is to build and operate world-class facilities on behalf of the East Asian regions, as a counterpart to the European Southern Observatory (ESO). Leading astronomical facilities such as ALMA, TMT, GMT, and SKA are mega projects which require enormous economic resources. It is difficult for any observatory or any country to fund such facilities on its own. EAO intends to combine the resources and manpower in our East Asian regions, in order to play a leading role in the next generation frontier instruments. The EACOA institutes: NAOC, NAOJ, KASI, and ASIAA, have authorized the EAO to take on the operations of the James Clerk Maxwell Telescope (JCMT) on Mauna Kea as their first joint venture. In this talk, we will report on the development of EAO, our current operations of JCMT, and our future aspirations.

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THE AKARI DEEP FIELD SOUTH: PUSHING TO HIGH REDSHIFT

  • Clements, David L.
    • 천문학논총
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    • 제32권1호
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    • pp.275-279
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    • 2017
  • The AKARI Deep Field South (ADF-S) is a large extragalactic survey field that is covered by multiple instruments, from optical to far-IR and radio. I summarise recent results in this and related fields prompted by the release of the Herschel far-IR/submm images, including studies of cold dust in nearby galaxies, the identification of strongly lensed distant galaxies, and the use of colour selection to find candidate very high redshift sources. I conclude that the potential for significant new results from the ADF-S is very great. The addition of new wavelength bands in the future, eg. from Euclid, SKA, ALMA and elsewhere, will boost the importance of this field still further.

Wastewater process modeling

  • Serdarevic, Amra;Dzubur, Alma
    • Coupled systems mechanics
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    • 제5권1호
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    • pp.21-39
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    • 2016
  • Wastewater process models are the essential tools for understanding relevant aspects of wastewater treatment system. Wastewater process modeling provides more options for upgrades and better understanding of new plant design, as well as improvements of operational controls. The software packages (BioWin, GPS-X, Aqua designer, etc) solve a series of simulated equations simultaneously in order to propose several solutions for a specific facility. Research and implementation of wastewater process modeling in combination with computational fluid dynamics enable testing for improvements of flow characteristics for WWTP and at the same time exam biological, physical, and chemical characteristics of the flow. Application of WWTP models requires broad knowledge of the process and expertise in modeling. Therefore, an efficient and good modeling practice requires both experience and set of proper guidelines as a background.

건강증진을 위한 부문 간 협력의 이해 (Understanding Intersectoral Collaboration in Health Promotion)

  • 강은정
    • 보건교육건강증진학회지
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    • 제30권4호
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    • pp.17-24
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    • 2013
  • Objectives: This paper aims to give a review on the concept, the type, and the purpose of intersectoral collaboration, to provide a framework of intersectoral collaboration, and to review the effectiveness of intersectoral collaboration. Methods: Peer-reviewed journals were searched in Pubmed using the terms of 'intersectoral collaboration,' 'multi-sector policy,' 'intersectoral partnership,' and 'cross-sector collaboration.' In total, 240 papers were identified. After reviewing the abstracts of these papers, 59 papers were chosen to be reviewed in full-text. Contents were extracted from these papers that were pertinent to the research questions. Results: Intersectoral collaboration has been advocated since Alma Ata Declaration. However, it has been largely ignored in practice. Various factors including context, support, task, team, interactional process, individual, and overarching factors can affect the success and the failure of intersectoral collaboration. Conclusions: Some strategies to facilitate intersectoral collaboration activities and future research agenda were suggested.

Breaking the cosmic degeneracy with the supercluster straightness

  • Shim, Junsup;Lee, Jounghun;Baldi, Marco
    • 천문학회보
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    • 제39권2호
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    • pp.44.1-44.1
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    • 2014
  • 최근 연구에서 발디 등은 우주론적 축퇴라는 이슈를 부각시켰다. 우주론적 축퇴는 실제 우주가 다수의 대안 우주론을 동시에 복합적으로 가질 때 거대 구조를 이용한 기존의 통계적인 방법만으로 우주론을 단정적으로 구별해 내기 충분치 않다는 것을 의미한다. 이 연구에서는 초은하단 스파인(spine)의 비크기(specific size)가 우주론적 축퇴를 완화할 수 있는지 조사하였다. f(R) 중력과 무거운 중성미자가 동시에 복합적으로 적용되는 다체 수치실험의 헤일로들을 분석한 결과, f(R) 중력이 비크기에 미치는 영향을 최대한으로 억제하는 ${\sum}_im_{{\nu}_i}$의 값이 기존의 통계적인 방법들에서 얻은 값과 다름을 확인하였다. 더 나아가 z=0.3 이상의 높은 적색편이에서는 f(R) 중력과 ${\sum}_im_{{\nu}_i}$ 조합한 모든 우주에서의 초은하단 평균 비크기가 표준 우주론인 ${\Lambda}$ CDM과 통계적으로 유의미하게 달라지는 것을 확인하였다. (arXiv:1404.3639v1)

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BISTRO: B-fields In STar-forming Region Observations

  • 권우진
    • 천문학회보
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    • 제41권2호
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    • pp.47.2-47.2
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    • 2016
  • We introduce a magnetic field survey of the Gould Belt clouds using the James Clerk Maxwell Telescope (JCMT) POL-2: B-fields In STar-forming Region Observations (BISTRO). POL-2 with SCUBA-2 on JCMT is a unique facility, as it is the only facility world-wide that can map the magnetic field within cold dense cores and filaments on scales of ~1000 AU in nearby star-forming regions, such as Taurus and Ophiuchus. It can provide a link between the B-field measured on arc-minute scales by Planck and BLASTPOL and measurements made on arc-second scales by interferometers such as CARMA, SMA, and ALMA. BISTRO was awarded 224 hours toward 16 fields for the next 3 years and started to take data in the 2016A semester.

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