• 제목/요약/키워드: HST

검색결과 197건 처리시간 0.022초

OPTICAL AND NEAR-INFRARED IMAGING OF THE IRAS 1-JY SAMPLE OF ULTRALUMINOUS INFRARED GALAXIES

  • KIM D.-C.
    • 천문학회지
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    • 제36권3호
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    • pp.159-165
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    • 2003
  • Optical (R) and near-infrared (K') images of the IRAS 1-Jy sample of 118 ultraluminous infrared galaxies have been studied. All but one object in the 1-Jy sample show signs of strong tidal interaction/merger. Most of them harbor a single disturbed nucleus and are therefore in the later stages of a merger event. Single-nucleus ULIGs show a broad distribution in host magnitudes with significant overlap with those of quasars. The same statement applies to R - K' colors in ULIG and quasar hosts. An analysis of the surface brightness profiles of the host galaxies in single-nucleus sources reveals that about $35\%$ of the Rand K' surface brightness profiles are well fit by an elliptical-like $R^{1/4}$-law, while only $2\%$ are well fit by an exponential disk. Another $38\%$ of the single-nucleus systems are fit equally well with an exponential or de Vaucouleurs profile. Elliptical-like hosts are most common among merger remnants with Seyfert 1 nuclei ($83\%$) and Seyfert 2 optical characteristics ($69\%$). The mean effective radius of these ULIGs is 4.80 $\pm$ 1.37 kpc at Rand 3.48 $\pm$ 1.39 kpc at K'. These values are in excellent agreement with recent quasar measurements obtained at H with HST. The hosts of elliptical-like 1-Jy systems follow with some scatter the same ${\mu}e - r_e$ relation, giving credence to the idea that some of these objects may eventually become elliptical galaxies if they get rid of their excess gas or transform this gas into stars.

고속철도 안전확보를 위한 노선 인접 광산의 발파패턴 제안 (A Suggestion of Blasting Patterns of a Mine closed to Railway Line for Securing Safety of High Speed Train)

  • 김현기;이성혁;이진욱;최찬용
    • 한국구조물진단유지관리공학회 논문집
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    • 제19권5호
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    • pp.1-9
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    • 2015
  • 2015년도 개통을 위하여 호남고속철도 건설사업 건설이 진행되고 있으며, 이 노선은 차세대 고속열차의 HEMU-430X가 세계 최초로 주행하게 된다. 한편, 인근에 위치한 석회석 광산이 지속적인 발파작업을 시행하고 있으며, 더욱이 향후 연결통로 개설을 통하여 이 노선의 하부를 관통할 예정이다. 이 경우에 광산 발파로 인한 고속철도의 안정성과 열차주행으로 인한 광산 안정성 모두 검토되어야 한다. 이를 위하여 광산 발파진동계측을 통하여 진동추정식을 작성하였으며, 광산발파로 인한 철도 안정성을 정량적으로 검토하였다. 특히, 계측결과 분석에 의한 계측관리기준으로 0.5 kine(cm/sec)을 설정하여, 광산 발파진동을 제어하고자 하였으며, 발파진동의 제어를 통하여 고속열차의 안정성을 확보할 수 있는 광산의 발파패턴을 제안하였다. 또한, 고속열차 주행에 따른 진동이 광산에 미치는 영향을 수치해석적으로 검토하여 광산의 안정성도 확보할 수 있도록 하였다.

MMPI 임상척도와 성격척도를 통해 살펴 본 공황장애 환자의 특성에 대한 연구 (The study on characteristics of panic disorder through clinical and personality scales in MMPI of patients with Panic disorder)

  • 김진형;국윤재;최성열;김태헌;류영수;강형원
    • 동의신경정신과학회지
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    • 제16권1호
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    • pp.129-142
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    • 2005
  • Objectives : This study was to investigate MMPI profile on clinical scales and personality scales of Panic Disorder patients. Methods : Thirty eight Panic Disorder patients and twenty eight normal control were administered the MMPI. Experimental design was done by nonequivalent control group and statistics were crosstabs, chi-square test, ANOVA, t-test and cluster analysis Results and Conclusions : 1. The MMPI clinical scales profile of Panic Disorder patients was neurotic profile of 2-7 type. Panic Disorder patients was elevated the other scales except L, K, Mf and Ma scales for control group. 2. A result of grouping MMPI in Panic Disorder patients, we could classify into 3 different groups. Group 1 is a profile of conversional neurosis. Group 2 is a normal proflie. Group 3 is a proflie of $'{\Lambda}'$ type neurosis. 3. Personality characteristics in Panic Disorder patients was lowed scores in HST, NAR scales, elevated the other scales except ANT scale. Specially in PAG, AVD scales showed high scores.

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A deep and High-resolution Study of Ultra-diffuse Galaxies in Distant Massive Galaxy Clusters

  • Lee, Jeong Hwan;Kang, Jisu;Jang, In Sung;Lee, Myung Gyoon
    • 천문학회보
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    • 제44권1호
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    • pp.38.4-38.4
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    • 2019
  • Ultra-diffuse galaxies (UDGs) are intriguing in the sense that they are much larger than dwarf galaxies but have much lower surface brightness than normal galaxies. To date, UDGs have been found only in the local universe. Taking advantage of deep and high-resolution HST images, we search for UDGs in massive galaxy clusters in the distant universe. In this work, we present our search results of UDGs in three massive clusters of the Hubble Frontier Fields: Abell 2744 (z=0.308), Abell S1063 (z=0.348), and Abell 370 (z=0.375). These clusters are the most distant and massive among the host systems of known UDGs. The color-magnitude diagrams of these clusters show that UDGs are mainly located in the faint end of the red sequence. This means that most UDGs in these clusters consist of old stars. Interestingly, we found a few blue UDGs, which implies that they had recent star formation. The radial number densities of UDGs clearly decrease in the central region of the clusters in contrast to those of bright galaxies which keep rising. This implies that a large fraction of UDGs in the central region were tidally disrupted. These features are consistent with those of UDGs in nearby galaxy clusters. We estimate the total number of UDGs (N(UDG)) in each cluster. The abundance of UDGs shows a tight relation with the virial masses (M_200) of thier host systems: M_200 \propto N(UDG)^(1.01+/-0.05). This slope is found to be very close to one, indicating that efficiency of UDGs does not significantly depend on the host environments. Furthermore, estimation of dynamical masses of UDGs indicates that most UDGs have dwarf-like masses (M_200 < 10^11 M_Sun), but a few UDGs have $L{\ast}$-like masses (M_200 > 10^11 M_Sun). In summary, UDGs in distant massive clusters are found to be similar to those in the local universe.

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Observational Feature of Ejecta-Companion Interaction of A Type Ia SN 2021hpr Via The Very Early Light Curve

  • 임구;임명신;백승학;윤성철;최창수;김소피아;서진국;강원석;김태우;성현일;김용기;윤요라
    • 천문학회보
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    • 제46권2호
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    • pp.50.3-51
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    • 2021
  • The progenitor of Type Ia supernovae is largely expected as a close binary system of a carbon/oxygen white dwarf (WD) primary and its secondary non-degenerate (single degenerate; SD) or degenerate companion (double degenerate; DD). Here we present a high-cadence monitoring observation of SN 2021hpr in a spiral galaxy, NGC 3147. SN 2021hpr shows typical characteristics as a normal type Ia supernova from its photometric (Δm15(B)=1.01±0.03, dust free MB,max=-19.45±0.02) and spectroscopic data. To investigate its progenitor system, we fit the early part of BVRI-band light curve simultaneously with a combined version of ejecta-companion and simple power-law model. As a result, we found a significant feature of an early excess possibly from a 7.63±0.52R-sized companion at the optimal viewing angle while the fit is not successful at the common viewing angle. No possible red sources brighter than F555W=-7.01 AB mag is detected at the SN location in Hubble Space Telescope (HST) pre-explosion images, excluding massive stars with initial mass of >16M as companions. We suggest the progenitor system of SN 2021hpr can be a fairly large companion such as a main sequence, a low mass subgiant, and a helium giant star. In addition, a possibility of the ejecta-Disk Originated Matter (DOM) interaction for the DD scenario considering linearly-rising early flux still remains.

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Random Forest 기법을 이용한 도심지 MT 시계열 자료의 차량 잡음 분류 (Classification of Transport Vehicle Noise Events in Magnetotelluric Time Series Data in an Urban area Using Random Forest Techniques)

  • 권형석;류경호;심익현;이춘기;오석훈
    • 지구물리와물리탐사
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    • 제23권4호
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    • pp.230-242
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    • 2020
  • 201 6년 9월에 발생한 경주지진원 구역에 대한 정밀 지질구조 규명을 위해 MT 탐사를 적용하였다. 경주지역의 MT 측정자료는 조사지역 인근의 지하철, 전력선, 공장, 주택, 농경지에서 발생된 전기적 잡음과 철도, 도로에서의 차량잡음 등으로 인해 측정자료 왜곡이 심하게 발생되었다. 이 연구에서는 고속철도 및 고속도로와 인접한 4개소의 MT 탐사자료에 기계학습 기법을 적용하여 차량잡음이 포함된 시계열을 분류하였다. 고속열차 잡음이 포함된 시계열에 대해서는 확률적 경사 하강법, 서포트 벡터 머신과 랜덤 포레스트 3가지의 분류모델을 적용하여 그 결과를 비교하였다. 대형트럭 잡음이 포함된 시계열 자료에 대해서는 Hx 성분, Hy 성분과 Hx & Hy 합성성분 크기에 대한 3가지의 샘플 자료를 준비하였으며 랜덤 포레스트 분류모델을 구성하여 그 성능을 평가하였다. 마지막으로 차량잡음 제거 효과 분석을 위하여 차량잡음 제거 전후의 시계열, 진폭 스펙트럼과 겉보기비저항 곡선을 비교하였으며, 이를 통해 차량잡음이 영향을 미치는 주파수 대역과 차량잡음 제거 시 발생될 수 있는 문제점에 대해 고찰하였다.

화병환자의 MMPI 프로파일과 성격특성 연구 (A Study on the Characteristics of MMPI Profile and Personality in Patients with Hwa-byung)

  • 김지훤;박보라;장현호;김태헌;류영수;강형원
    • 동의신경정신과학회지
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    • 제20권3호
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    • pp.189-203
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    • 2009
  • Objectives : This study was to analyze characteristics of MMPI profile, personality and defensive mechanism on 32 Hwa-byeng patients. Methods : 32 Hwa-byeng patients and 28 normal control group were administered the MMPI. The characteristics of MMPI profile and the clinical scales of personality and defensive mechanism were analyzed statistically. Results : 1. Half of female Hwa-byeng patients are in their forties, twelve patients are high school graduates, housewives seem to have Hwa-byeng more than workers, and married ones have Hwa-byeng more than singles, divorcees or separated one 2. 60.6% patients are getting stressed from their husbands(the specific reasons are infidelity(55%), incapability(25%) and violence(20%)). And the rest are from in-law(28.8%), children(6.4%) and their own parents(3.2%). 3. MMPI profile of Hwa-byeng patients appeared as a type of 3-1 elevated by the scale of 3(Hy) and 1 (Hs). And Hwa-byeng patients appeared significantly high in the rest of scales except L, K, Mf and Ma scales comparing to control group. 4. Hwa-byeng patients were classified into 3 groups. First group is "V" type which is high in K scale and low in 3 (Hy), 4(Pd), 6(Pa). Second group is "V" type which is high in K scale and high in 3(Hy), 4(Pd), 6(Pa). Third group is high in F scale and high in 1(Hs), Z(D), 3(Hy), 4(Pd), 6(Pa), 7(Pt), 8(Sc) and 0(Si). 5. The analysis on MMPI profiles indicates that the thirties are highier in F scale than the fifties, the fifties are highier in Hy scale than the forties, workers are highier in Pd scale than housewives, singles or divorcees are highier in Pa scale than the married. 6. The characteristics of personality in Hwa-byeng patients are as follows. They are significantly lower in HST, NAR and very higher in CPS, PAG, DEP, STY, AVD, SZD comparing to control group. Especially in AVD and SZD scales are appeared the highest.

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