• Title/Summary/Keyword: merger

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Discovery of an elliptical jellyfish galaxy with MUSE

  • Sheen, Yun-Kyeong;Smith, Rory;Jaffe, Yara;Kim, Minjin;Duc, Pierre-Alain;Ree, Chang Hee;Nantais, Julie;Candlish, Graeme;Yi, Sukyoung;Demarco, Ricardo;Treister, Ezequiel
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.46.2-46.2
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    • 2017
  • We will present a discovery of an elliptical jellyfish galaxy in Abell 2670 (Sheen et al. 2017, ApJL, 840, L7). Our MUSE IFU spectra revealed a rotating gas disk in the center of the galaxy and long ionised gas tails emanating from the disk. Its one-sided tails and a tadpole-like morphology of star-forming blobs around the galaxy suggested that the galaxy is experiencing strong ram-pressure stripping in the cluster environment. Stellar kinematics with stellar absorption lines in the MUSE spectra demonstrated that the galaxy is an elliptical galaxy without any hint of a stellar disk. Then, the primary question would be the origin of the rich gas component in the elliptical galaxy. A plausible scenario is a wet merger with a gas-rich companion. In order to investigate star formation history of the system (the galaxy and star-forming blobs), we derived star-formation rate and metallicity from the MUSE spectra. Photometric UV-Optica-IR SED fitting was also performed using GALEX, SDSS, 2MASS and WISE data, to estimate dust and gas masses in the system. For a better understanding of star formation history and environmental effect of this galaxy, FIR/sub-mm follow-up observations are proposed.

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Dependence of Barredness of Late-Type Galaxies on Galaxy Properties and Environment

  • Lee, Gwang-Ho;Park, Chang-Bom;Lee, Myung-Gyoon;Choi, Yun-Young
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.75.2-75.2
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    • 2010
  • We investigate the dependence of occurrence of bar in galaxies on galaxy properties and environment. The environmental conditions considered include the large-scale background density and distance to the nearest neighbor galaxy. We use a volume-limited sample of 33,296 galaxies brighter than $M_r$=-19.5+5logh at $0.02{\leqq}z{\leqq}0.05489$, drawn from the Sloan Digital Sky Survey Data Release 7. We classify the galaxies into early and late types, and identify bars by visual inspection. We find that the fraction of barred galaxies ($f_{bar}$) is 18.2% on average in the case of late-type galaxies, and depends on both u-r color and central velocity dispersion $(\sigma);f_{bar}$ is a monotonically increasing function of u-r color, and has a maximum value at intermediate velocity dispersion (${\sigma}{\simeq}170km\;s^{-1}$). This trend suggests that bars are dominantly hosted by systems having intermediate-mass with no recent interaction or merger history. We also find that $f_{bar}$ does not directly depend on the large-scale background density as its dependence disappears when other physical parameters are fixed. We discover the bar fraction decreases as the separation to the nearest neighbor galaxy becomes smaller than 0.1 times the virial radius of the neighbor regardless of neighbor's morphology. These results imply that it is difficult for bars to be maintained during strong tidal interactions, and that the source for this phenomenon is gravitational and not hydrodynamical.

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The Spatial Characteristics and Types of Municipal Mergers in Japan : Focused on the Tokyo Metropolitan Area (일본 행정구역 개편의 공간특성과 유형 - 수도권 지역을 중심으로 -)

  • Cho, A-Ra
    • Journal of the Korean association of regional geographers
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    • v.16 no.6
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    • pp.653-672
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    • 2010
  • This study aimed to examine the characteristics and types of reformation of local administrative districts in a metropolitan area, focused on the experiences of Japan, where municipal mergers were carried out extensively over the last ten years. Local administrative districts substantially have spatial characteristics. Therefore, the reformation of local administrative districts should be followed by a detailed analysis of the characteristics of the local area. Unlike other regions, the metropolitan area of Japan shows discriminative characteristics of finance, population and centrality. In addition, there are many types of regional context within a metropolitan area. These could be categorized by finance, population, centrality and basic industry. In conclusion, I revealed that municipal mergers could be categorized by their background and process and many issues were contained in each category. It had a meaning that municipal mergers had characteristics that expanded the regional inequality. Therefore, different approaches considering regional characteristics would be required for a municipal merger to be a useful way for regional development.

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A Study on the Screen Space and Motion of Tabaimo Animation (타바이모(TABAIMO) 애니메이션의 화면 공간과 움직임에 대한 연구)

  • Lee, Jin-Young
    • Cartoon and Animation Studies
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    • s.35
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    • pp.89-106
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    • 2014
  • According to Norman McLaren, a Canadian animator, "Animation is not art of moving pictures but art of drawn motions". As he puts it, animation performs the role of magic that turns static to dynamic. Particularly, the space of animation, which is generated through merger of several layers, creates distinctive space that is not to be found in other art genres. Also, the motion of animation, which, unlike live action in film, can be limitlessly created according to a director's subjective domain, has a more autonomous existence. In this paper, I study the space and motion in animation grounded in a director's subjective domain, based on the works by Tabaimo, the Japanese animator director and modern artist. She made an independent use of color sense and perspective that maximized a flat surface, which contributed to creating a new world that doesn't exist in reality. Motion created in such a space is more relative than universal. Therefore, Tabaimo's animation has made aggressive use of a device that gives more originality to the director's themed world, while audience can participate in the strange but new world.

A Study on the Domestic Waste Occurence and Admistration Condition of Iksan City (익산시의 생활폐기물 발생 및 관리 현황조사)

  • 육찬남
    • Journal of environmental and Sanitary engineering
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    • v.13 no.3
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    • pp.79-84
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    • 1998
  • The study result on the domestic waste occurrence and admistration condition of Iksan City as follows ; 1. The year of 1995 has observed a radically decreasing ratio of per capita waste generation compared to the previous year by 26.2%, owing to the publication of the new amendment of volume based charge as well as to the rural population included through the merger of Iksan City and Iksan Country ; the daily quantity of domestic waste for Iksan residents in 1997 was calculated to be $0.66kg/capita{\cdot}day$. 2. Waste generation in nonresidential areas were $8.04kg/capita{\cdot}day$ in average ; the quantity per capita in market places was observed to generate the largest, $36.76kg/capita{\cdot}day$, while that of services was the smallest $0.25kg/capita{\cdot}day$. 3. The average generation per capita of household waste was $0.23kg/capita{\cdot}day$ in the area which has no volume based charge system. This area showed no difference from those of other areas ; the apparent density of the waste recorded the lowest $0.llkg/{\ell}$ for District Offices, while the highest among the classified fields was $0.40kg/{\ell}$ of the Fire Station. 4. Iksan City showed great contribution by decreasing the absolute quantity of waste for landfill by waste classfication, according to the days of the week and reutilizing recyclable waste since August, 1997. 5. Location of a landfill site for disposal of nonrecyclable waste will cause a serious problem to the community and it will be highly recommendable to have governmental support and professtional consultation as well as open discussions, such as hearings, for the settlement of the problem.

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The Role of Korea Institute for Health and Social Affairs (한국보건사회연구원의 역할)

  • Jo, Jaegoog
    • Health Policy and Management
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    • v.28 no.3
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    • pp.217-221
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    • 2018
  • Korea Institute for Family Planning (KIFP) was established on July 1, 1971 (Law 2270) and Korea Health Development Institute (KHDI) was established on April 19, 1976 (Law 2857). Korea Institute for Population and Health (KIPH) was formed through the merger of KIFP and KHDI (Act 3417) on July 1, 1981. Korea Institute for Health and Social Affairs (KIHASA), the former KIPH, was renamed KIHASA on December 30, 1989 (Law 4181) with its additional function of research in social security. It was transferred on January 29, 1999 to the Office of State Affairs Coordination pursuant to the Law on the Establishment, Operation and Promotion of State-Sponsored Organizations (Law 5733). Annually it conducts approximately 50 short- and long-term research projects to accumulate a wide range of research experience. Also it studies and evaluates the primary issues of national health services, health and medical industries, social insurance, social security, family welfare, and population. it conducts joint research projects and active information exchange programs with related domestic and international organizations through seminars and conferences. It executes specific research and development projects according to the government's requests. it educates and trains people domestically and abroad by disseminating a wide-range of information on health and social affairs. it conducts national household surveys on areas of fertility, health and medical care of the disabled, the elderly, and low-income earners. The mid- and long-term research goals of KIHASA should be established and managed systematically. A new organization such as 'Center for Policy Evaluation' is needed to enhance research abilities and experiences. Able research personnels should be recruited and current researchers should try to develop their abilities.

Enhanced Nitrogen in Morphologically Disturbed Blue Compact Galaxies at 0.20 < z < 0.35: Probing Galaxy Merging Features

  • Chung, Jiwon;Rey, Soo-Chang;Sung, Eon-Chang;Yeom, Bum-Suk;Humphrey, Andrew;Yi, Wonhyeong;Kyeong, Jaemann
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.39-39
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    • 2013
  • We present a study of correlations between the elemental abundances and galaxy morphologies of 91 blue compact galaxies (BCGs) at z=0.20-0.35 with Sloan Digital Sky Survey (SDSS) DR7 data. We classify the morphologies of the galaxies as either 'disturbed' or 'undisturbed', by visual inspection of the SDSS images, and using the Gini coefficient and M20. We derive oxygen and nitrogen abundances using the Te method. We find that a substantial fraction of BCGs with disturbed morphologies, indicative of merger remnants, show relatively high N/O and low O/H abundance ratios. The majority of the disturbed BCGs exhibit higher N/O values at a given O/H value compared to the morphologically undisturbed galaxies, implying more efficient nitrogen enrichment in disturbed BCGs. We detect Wolf-Rayet (WR) features in only a handful of the disturbed BCGs, which appears to contradict the idea that WR stars are responsible for high nitrogen abundance. Combining these results with Galaxy Evolution Explorer (GALEX) GR6 ultraviolet (UV) data, we find that the majority of the disturbed BCGs show systematically lower values of the $H{\alpha}$ to near-UV star formation rate ratio. The equivalent width of the $H{\beta}$ emission line is also systematically lower in the disturbed BCGs. Based on these results, we infer that disturbed BCGs have undergone star formation over relatively longer time scales, resulting in a more continuous enrichment of nitrogen. We suggest that this correlation between morphology and chemical abundances in BCGs is due to a difference in their recent star formation histories.

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Internal kinematics of dwarf early-type galaxies with blue-center in the Virgo Cluster from Gemini GMOS long-slit spectroscopy

  • Chung, Jiwon;Rey, Soo-Chang;Sung, Eon-Chang;Lee, Youngdae;Kim, Suk;Lee, Woong
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.33.1-33.1
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    • 2016
  • Dwarf elliptical galaxies (dEs), the most abundant galaxy type in clusters, were recently shown to exhibit a wide variety in their properties. Particularly, the presence of blue cores in some dEs, what we call dE(bc), supports the scenario of late-type galaxy infall and subsequent transformation into red, quiescent dEs. While several transformation mechanisms for these dE(bc)s within cluster environment have been proposed, all these processes are able to explain only some of the observational properties of dEs. In this context, internal kinematic properties of dE(bc)s provide the most crucial evidence to discriminate different processes for the formation of these galaxies. We present Gemini Multi Object Spectrograph (GMOS) long-slit spectroscopy of two dE(bc)s in the Virgo cluster. We obtained radial profiles of velocity and velocity dispersion out to ~1.3 effective radius. We found that two dE(bc)s exhibit kinematically decoupled components as well as distinct peculiar features in velocity profiles, supporting the scenario of mergers. We also found that these galaxies are structurally compatible with low surface brightness component of blue compact dwarf galaxies. We suggest that a part of dE(bc)s in the Virgo Cluster were formed through galaxy merger in low density environment such as galaxy group or outskirt of the cluster, and then were quenched by subsequent effects within cluster environment.

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Study on Ways to Improve Military Logistics Systems Based on IPA Analysis (IPA 분석을 활용한 군 물류체계 개선방안에 대한 연구)

  • Bae, Kuk-Hwan;Gong, Jeong-Min;Yeo, Gi-Tae
    • Journal of Digital Convergence
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    • v.15 no.3
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    • pp.139-146
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    • 2017
  • This study endeavors to propose factors that should be intensively managed by using an IPA model to analyze the strengths of military logistics. Based on the improvement measures, we constructed a questionnaire with 5 points of Likert scale and analyzed the importance and satisfaction through SPSS 23. Examination of several evaluation factors revealed 'expansion of and modernization storage facilities' as the most important factor, 'merger and abolition of regional logistics work' (3.56) had the highest satisfaction level. Factors involving the expansion and modernization of the storage facilities showed the largest difference between importance level and satisfaction level, at 2.01. This indicates the necessity for an overall review of the expansion and modernization of storage facilities related to military logistics. This study aims to identify the areas that should be improved firstly in military logistics and concentrate on management to create more effective results. Thus it suggests that this study has a concentration on management for the streamlining of military logistics.

A Study on the Performance of the M&A Firm in KOSDAQ (코스닥시장 M&A기업의 성과에 관한 연구)

  • Kim, Kyung-Sik
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.1 s.45
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    • pp.219-229
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    • 2007
  • The results of the research in M&A firms in the KOSDAQ market are as follows. First, the effect of the M&A disclosure at the time of disclosure was that the positive (+) cumulative abnormal return (CAR) can be interpreted as an increase in the value of the firm; however, in the long run, firms which used the KOSDAQ index and the control firm, which did not use the index were found to have conflicting results. Second, the findings show that the rise in value of general firms resulting from a M&A were higher that those of venture firms. Third, in testing the performance extrapolation hypothesis, it was shown that the performance of "value" firms (firms with a high B/M ratio but poor performance in the past) was better after a M&A than those of the "glamour" firms and that the performance extrapolation hypothesis was substantiated. Fourth, it can be construed that a size effect in a merger exists. The CAR of the small firms surpasses those of large firms. Fifth, in verifying operating performance, most variables showed a positive (+) value at the time of M&A but showed a negative (-) value after a M&A. These results show that because on the Korean KOSDAQ market, M&A are approached from a financial rather than an economic aspect, it can be inferred that it lowers the firms value.

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