• Title/Summary/Keyword: space morphology

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An HI study of a tidally interacting BCD pair, ESO 435-IG20 and ESO-IG16

  • Kim, Jinhyub;Sung, Eon-Chang;Chung, Aeree
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.50.1-50.1
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    • 2013
  • Blue Compact Dwarf galaxies (BCDs) are systems which have been experiencing the bursts of star formation in their central region. As one of the origins of active star formation, tidal interaction (merger or fly-by between dwarf galaxies) has been suggested. A pair of BCDs, ESO 435-IG20 and ESO 435-IG16, are suspected to be a good example of such case. They are located at a similar redshift and separated only by ~130 kpc at their distances. In addition a bridge-like HI structure has been found between these two BCDs in the HIPASS survey. In this study, using the ATCA HI data of a much better resolution, we probe the gas morphology and kinematics of individual galaxies. We discuss how tidal interaction is responsible for the high star formation rate in this BCD pair.

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Terminal Myelocystocele : Pathoembryogenesis and Clinical Features

  • Lee, Ji Yeoun;Kim, Kyung Hyun;Wang, Kyu-Chang
    • Journal of Korean Neurosurgical Society
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    • v.63 no.3
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    • pp.321-326
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    • 2020
  • There has been confusion in the classification of terminal myelocystocele (TMCC) due to its diverse morphology and vague pathoembryogenesis. TMCC could be summarized as having the essential features of an elongated caudal spinal cord extruding out of the dorsal extraspinal space that fuses with the subcutaneous fat, which is in the shape of a trumpet-shaped cerebrospinal fluid-filled cyst. The extraspinal portion of the extruded spinal cord is nonfunctional. The morphological features suggest that TMCC is formed during secondary neurulation, specifically the failure of the degeneration of the secondary neural tube near the time of the terminal balloon. This review discusses the definition, as well as the clinical and surgical features, of TMCC with special emphasis on its pathoembryogenesis.

Preparation of Porous Layered Carbon Using Magadiite Template (Magadiite 주형을 이용한 층상 카본의 합성)

  • Choe, Seok-Hyon;Jeong, Soon-Yong;Oh, Seong-Geun;Kwon, Oh-Yun
    • Applied Chemistry for Engineering
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    • v.16 no.3
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    • pp.408-412
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    • 2005
  • Porous layered carbon was prepared by interlayer pyrolysis of pyrolysis fuel oil (PFO) using magadiite template and successive dissolution of template. Particle morphology was plate type with d-spacing of approximately 0.7 nm and it had constant interlayer space. Specific surface area was $147{\sim}385m^2/g$ depending upon template type, mixing ratios and pyrolysis time.

Preparation of Layered Carbon Using Layered Silicate Template (층상 실리케이트 주형을 이용한 층상 카본의 합성)

  • Jeong, Eun-Il;Jeong, Soon-Yong;Kwon, Oh-Yun
    • Applied Chemistry for Engineering
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    • v.16 no.1
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    • pp.68-73
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    • 2005
  • Porous layered carbon was prepared by interlayer pyrolysis of pyrolysis fuel oil (PFO) using layered silicate template and successive dissolution of template. Particle morphology was plate type with d-spacing of 0.78~0.82 nm and constant interlayer space. Specific surface area was $30{\sim}576m^2/g$ depending upon template type, mixing ratios, pyrolysis temperature and pyrolysis time.

Road Boundary Detection on Highway with Searching Region of Interest on the Hough Transform Domain (Hough 변환된 영역의 관심 영역 검색 방법을 이용한 고속도로의 도로 윤곽선 검출)

  • Lin, Haiping;Bae, Jong-Min;Kim, Hyong-Suk
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.297-299
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    • 2006
  • Searching the region of interest on the Hough transform domain is done to determine the real road boundary on the high speed way. The mathematical morphology is employed to obtain the gradient image which is utilized in Hough transform. Many possible candidates of lines could appear on the ordinary road environment and simple selection of the strongest line segments likely to be fault boundary lines. To solve such problem, the search area for the candidates of the road boundary which is called the region of interest is limited on the Hough space. The effectiveness of the proposed algorithm has been shown with experimental results.

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Face Detection by Eye Detection with Progressive Thresholding

  • Jung, Ji-Moon;Kim, Tae-Chul;Wie, Eun-Young;Nam, Ki-Gon
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1689-1694
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    • 2005
  • Face detection plays an important role in face recognition, video surveillance, and human computer interface. In this paper, we present a face detection system using eye detection with progressive thresholding from a digital camera. The face candidate is detected by using skin color segmentation in the YCbCr color space. The face candidates are verified by detecting the eyes that is located by iterative thresholding and correlation coefficients. Preprocessing includes histogram equalization, log transformation, and gray-scale morphology for the emphasized eyes image. The distance of the eye candidate points generated by the progressive increasing threshold value is employed to extract the facial region. The process of the face detection is repeated by using the increasing threshold value. Experimental results show that more enhanced face detection in real time.

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Role of environment in the origin of early-type dwarf galaxies

  • Paudel, Sanjaya
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.55.2-55.2
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    • 2014
  • Role of environments is one of today's most widely discussed and debated topic in the field of extra-galactic astronomy. Extreme morphology-density relations found in low-mass galaxies are considered to be the result of an effective role played by environment in the evolution of these galaxies. I will present the results from our dedicated study of early-type dwarf galaxies (dEs) in different environments using imaging and spectroscopic data. We find that Virgo cluster dEs have a variety of structural and kinematic properties. A significant fraction of dEs possesses disk features, such as spiral arm and bar, while a central nucleus seems to be universal in these low mass galaxies. We also find that a majority of dEs are fast rotator and their rotation curves are much steeper than that of spiral galaxies of similar mass. Finally I will discuss how the different environmental mechanisms, i.e., gas-stripping or tidal interaction, can contribute to form heterogeneous dEs in Virgo cluster.

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High resolution Infrared spectroscopy of Planetary Nebula with IGRINS

  • Yu, Young Sam
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.93.2-93.2
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    • 2014
  • Planetary nebulae (PN) are the last stages of evolution of intermediate mass (1-8 Msolar) stars. Their shapes are thought to result from interactions between the present-day, fast (emerging white dwarf) and previously ejected, slow (red giant) stellar winds. The observation of young, bright PN, NGC7027 and BD+30 3639, was made on July 7, 2014 using the 2.7m Harlan J. Smith telescope at the McDonald Observatory. IGRINS with high spatial (0.27") and high spectral ($7.5km\;s^{-1}$) resolution will provide more nebular lines and excitation/abundances to constrain the morphology and kinematics of the Nebula and the PDRs. Combined with other archival data (X-ray, 2MASS, WISE, Spitzer, Herschel) for PN, high-resolution IR spectroscopy will yield insight into poorly understood aspects of PN morphologies and the late stages of binary star evolution.

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Relativistic Jets as Compact Radio Sources

  • Lee, Sang-Sung
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.39-39
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    • 2014
  • Studies of compact radio sources since the discovery of quasars have revealed a variety of physical properties: both in morphology and kinematics from sub-parsec to Mega-parsec scales, radiation mechanisms at frequencies from the radio to ${\gamma}$-rays, theoretical models for relativistic jets, etc. The frontier discovery of Very Long Baseline Interferometry (VLBI) observations for the compact extragalactic radio sources have triggered the extensive studies to investigate the underlying physics of the relativistic jets. In this context, the highest resolution VLBI surveys of ultra-compact radio sources provide the potentially important statistical basis for future study. As a tool of this study, a new millimeter VLBI network in Korea, the Korean VLBI Network (KVN) will paly an important role. We present results from large VLBI surveys of compact radio sources at millimeter wavelengths and discuss the prospects with the KVN on this study.

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P/2010 A2: Dynamical properties of dust and fragments

  • Kim, Yoonyoung;Ishiguro, Masateru
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.51.1-51.1
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    • 2016
  • We revisited a recent dust emission observed at a main-belt asteroid P/2010 A2 in terms of dynamical properties of dust particles and large fragments. This is a continued research that we made a presentation at the Korean Astronomical Society 2016 Spring Meeting, but we have strengthened the dynamical analysis of the ejecta to afford the conclusive evidence for the enigmatic phenomenon. We thus constructed a model to reproduce the morphology of the dust cloud based on the dust dynamics, and succeeded in reproducing the observed morphologies in different epochs over several years. For further analysis, we reconstructed the proper motion of large fragments with respect to the dust emission source estimated from our dust model. We found that (i) the dust cloud morphologies and (ii) observed trajectories of fragments are reasonably explained only when we assumed that both were ejected from a position where no object was detected from any observations. This result suggests that the original body was shattered by an impact, leaving only debris into space. In this presentation, we will compare our results with impact laboratory studies and provide an impact interpretation of the P/2010 A2 activity.

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