본문 바로가기
HOME> 보고서 > 보고서 검색상세

보고서 상세정보

천체물리연구
Basic Research on Astrophysics

  • 사업명

    (연구회소관출연기관)한국천문연구원<기초>

  • 과제명

    천체물리 연구

  • 주관연구기관

    한국천문연구원
    Korea Astronomy Observatory

  • 연구책임자

    송두종

  • 참여연구자

    김민선   김순옥   김종수   김홍서   노혜림   민영철   박영득   선광일   안상현   여아란   이영웅   ...  

  • 보고서유형

    최종보고서

  • 발행국가

    대한민국

  • 언어

    한국어

  • 발행년월

    2008-12

  • 과제시작년도

    2008

  • 주관부처

    교육과학기술부

  • 사업 관리 기관

    교육과학기술부

  • 등록번호

    TRKO200900074133

  • 과제고유번호

    1345072179

  • 키워드

    별 생성 기작.우주의 구조와 진화.고 에너지 천체물리.수치 천체물리.분광관측.슈퍼버블.Star formation.Structure and evolution of universe.High energy astrophysics.Numerical astrophysics Spectroscopy.superbubble.

  • DB 구축일자

    2013-04-18

  • 초록 


    The main research results produced by the international Center for Astrophysics GCAP) at Korea Astronomy and Space Science Instit...

    The main research results produced by the international Center for Astrophysics GCAP) at Korea Astronomy and Space Science Institute (KASI) can be summarized as follows.
    The weakly nonlinear process of gravitating system has fundamental importance in cosmology. We investigate whether Newton's gravity sufficient to handle the weakly nonlinear evolution stage of the large-scale cosmic structures. We resolve the issue by analytically deriving the density and velocity power spectra to the second order in the context of Einstein's gravity.
    In high energy astronomy/astrophysics, particularly the observations of far ultraviolet, X-ray, and gamma-ray signals provide valuable essential information on fascinating phenomena associated with compact objects such as white dwarfs, neutron stars (pulsars), and black holes. To understand the compact objects, we studied the X-ray and optical light curves of the magnetic cataclysmic variable MU Cam using the XMM-Newton data, and the optical data taken with 1 meter telescope of the Mt. Lemmon Optical Astronomy Observatory, KASI.
    We measured the hard (2-8 keV) X-ray luminosity function (XLF) of AGNs up to z = 5. At hight red-shifts, the wide area coverage of the Chandra Multiwavelength Project is crucial to detect rare and luminous (Lx > $10^{44}$ ergs $s^{-l}$) AGNs. The inclusion of samples from deeper published surveys, such as the Chandra Deep Fields, allows us to span the lower Lx range of the XLF. We find that the luminosity function is similar to that found in previous X-ray surveys up to z = 3 with an evolution dependent on both luminosity and redshift. At z > 3, there is a significant decline in the numbers of AGNs with an evolution rate similar to that found by studies of optically selected QSOs.
    We also obtain the global accretion solutions with the shocks in terms of a few flow parameters, namely, energy, angular momentum, black hole rotation parameter and the accretion rate, which effectively acts as the cooling parameter (Das & Chakrabarti 2008). We find that the accreting matter experiences centrifugal force which acts as a barrier, inducing a shock formation. In the study of propagation of UHECRs, we selected the groups of galaxies as mock observers that have similar halo gas temperature to the Local Group. We model the observer locations according to the strength of the magnetic field at the Local Group and estimate the fraction f in terms of magnetic field strength. We observed that the value of f is higher when observers are belong to the region of weaker magnetic field and vice versa.
    Since the first discovery of an extrasolar planet in 1995, more than 200 planets have been reported mostly around solar-type stars. Planetary systems in intermediate-mass (1.5 to 5 solar masses) stars should also be studied because they can give constraints on the roles of key factors controlling planet formation. We detected 9 exo-planet candidates from five year's observation of 55 K giants, and 1 candidate from 10 M giant stars. Our survey indicates larger planet detection frequency, about 16%, around intermediate mass stars.
    The main research focus of the simulation group of our center is to demonstrate that turbulence is one of important ingredients for control star formation. For this purpose, we did high-resolution MHD turbulence simulations for star formation in a molecular cloud. From a set of simulated data, we identified dense cores in the cloud, calculated the surface- and volume-integration terms in the virial equation. We have developed the numerical code to solve the MHD equations involving the bipolar diffuction term, and we are now performing the numerical simulations on the star formation. One of the highlights of our study is that the presence of self-gravity modifies the slopes of the core mass function (CMF) at the high-mass end. At low thresholds, the slope is shallower than the one predicted by pure turbulent fragmentation.
    We have estimated the fractal dimension of the molecular clouds associated with the H IT region Sh 156 in the Outer Galaxy. We selected the $^{12}CO$ cube data from the FCRAO CO Survey of the Outer Galaxy. Using a developed code within IRAF, we identified slice-clouds (2-dimensional clouds in velocity-channel maps) with two threshold temperatures to estimate the fractal dimension. The fractal dimensions was estimated to be D = 1.5 ~ 1.53 for NP $\geq$ 40, where P $\propto$ $A^{D/2}$ (P is perimeter and A is area), which is slightly larger than other results.
    We also found a new cloud in the direction toward north -east from AFGL 2591 (projected distance ~ 2.4 pc), which is probably associated with the AFGL 2591 cloud. The $^{12}CO$ spectrum clearly shows a blue-shifted high-velocity wing at around the velocity -20 ~ -10 km $s^{-1}$, but it is not clear whether this high-velocity component has a bipolar nature in our observations.
    We also studied the far-ultraviolet diffuse emission map of the Eridanus superbubble, obtained using the SPEAR/FIMS instrument. The features seen in the FUV image closely resemble those seen in the H$\alpha$ map, including two prominent arcs identified earlier in Ha. While it has been argued that the FUV emission in this region is mostly due to the scattering of star light by dust, a close spectral examination reveals that one of the arcs is abundant in molecules and dust while the other is mainly composed of atomic species.


    $\cdot$ 우주론/고에너지 천체물리 연구
    - 초기우주에서 비선형 요동 연구, 암흠에너지 모형 연구, 우주론적 SGWB의 변형 스팩트럼 연구
    - X-선 및 감마선 폭발체에 대한 찬드라 및 스위프트 위...

    $\cdot$ 우주론/고에너지 천체물리 연구
    - 초기우주에서 비선형 요동 연구, 암흠에너지 모형 연구, 우주론적 SGWB의 변형 스팩트럼 연구
    - X-선 및 감마선 폭발체에 대한 찬드라 및 스위프트 위성 데이터 분석
    $\cdot$ 별/행성 연구 분야
    - 새로운 DIBS 및 외계 행성 탐색을 위한 분광관측
    - SMA를 이용한 별 주면 원반의 밀도와 온도 분포 연구
    $\cdot$ 성간물질 연구 분야
    - 자화된 성간 기체의 회전측정 스팩트럼, 분산측정 스팩트럼 연구
    - 은하면 제 2 상한 성운의 CO 관측 연구, 메탄올 등의 화학적 특성 연구
    - Eridanus Superbubble의 원자외선 관측 연구


  • 목차(Contents) 

    1. 제 1 장 우주론/고에너지 천체물리 연구 ...13
    2. 제 1 절 우주론 ...13
    3. 제 2 절 Chandra Archival Survey : X-ray Point Sources in Galaxy Clusters ...17
    4. 제 3 절 Astrophysical Flows around Black Holes .....
    1. 제 1 장 우주론/고에너지 천체물리 연구 ...13
    2. 제 1 절 우주론 ...13
    3. 제 2 절 Chandra Archival Survey : X-ray Point Sources in Galaxy Clusters ...17
    4. 제 3 절 Astrophysical Flows around Black Holes ...28
    5. 제 4 절 Ultra High Energy Cosmic Rays ...43
    6. 제 5 절 자기격변변광성 MU Cam의 X-선과 광학 관측자료의 주기분석 ...50
    7. 제 2 장 별/행성 연구 ...64
    8. 제 3 장 성간물질 연구 ...71
    9. 제 1 절 난류를 띠고 있는 성간 분자운에서 별 생성 기작 이해: 분자운에서 별 생성 ...71
    10. 제 2 절 성간물질에서의 복사장과 성간물질 간 상호작용 연구 ...77
    11. 제 3 절 별 탄생 지역의 구조 및 물리 화학적 진화연구 - 천체화학의 연구 ...82
    12. 제 4 절 Eridanus Superbubble의 원자외선 관측 ...89
    13. 제 4 장 연구수행 결과 ...101
    14. 제 1 절 논문게재 실적 ...102
    15. 제 2 절 학술발표 실적 ...105
  • 참고문헌

    1. 전체(0)
    2. 논문(0)
    3. 특허(0)
    4. 보고서(0)

 활용도 분석

  • 상세보기

    amChart 영역
  • 원문보기

    amChart 영역