The CCAT is a 25 meter diameter submillimeter wave telescope, currently in the planning phase for construction and operation in the Atacama Desert, Chile. When it is operational, it will be the premier ground based facility for submillimeter wave astrophysics with an unmatched wide field survey capability and will host leading edge submillimeter imaging and spectroscopic focal plane arrays. The CCAT wide field survey will complement the high resolution capabilities of the nearby ALMA facility. I will describe the current plans, highlight the capabilities and present an opportunity for partnership in the consortium.

Understanding the environment of a supernova explosion and its consequent evolution is crucial in understanding the Galactic ecology. The diverse characteristics of supernova remnants (SNRs) reflect the nature of the progenitor star, of the explosion itself, and of the ambient medium. In this talk, I will present observational studies of two Galactic SNRs, Tycho and IC 443, focusing on their interaction with the ambient medium. From observations of Tycho, we discovered a thin (<10^17 cm) shock precursor, whose primary candidate is a cosmic ray (CR) precursor. The observed properties of the precursor suggest efficient CR acceleration in Tycho. IC 443 is the first and most studied SNR interacting with molecular clouds. Our results indicate that the remnant is interacting with small (~1arc min) isolated molecular clouds, which are likely to be remnants of the parental molecular clouds destroyed during the pre-SN evolution. From the line characteristics of shocked molecular clumps, we study an evolution of shocked molecular clumps.

지구환경변화를 주도하는 대표적 이슈는 (1). 지구온난화 기후변화와 (2). 오존층 파괴에 따른 생태계 영향과 (3). 국가간 대기오염 및 해양오염 등의 월경 문제이며 (4). 산업 발달과 도시화에 따른 자연환경 파괴의 광역화 이다. 이들 중 지구온난화는 국제적 감시와 저감을 위한 노력이 동반되지 않고는 달성될 수 없다. 동북아시아 기후구역의 온난화 감시에는 기상청의 안면도와 제주도 고산 지구대기감시관측소 등에서 온실기체 측정으로 적극 수행하고 있어 지구환경 연구에 대한 우리나라의 미래는 비교적 밝다. 동북아시아 지구환경 지역을 대표하는 한반도지역 대기(일명 배경대기)의 온실기체 이산화탄소의 연평균 농도는 2005년 제주도 고산 관측소 (환경부, 기상청)에서 관측한 결과 년 평균 381.6 ppm을 나타내었다(그림). 기상청 안면도 지구대기감시관측소에서는 385.3 ppm를 보였다. 연평균 증가율은 지난 13년간 (1990-2002년) 제주도 고산관측소에서 1.17 ppm - 2.02 ppm을 보였고 안면도에서는 1999년에서 2002년까지 4년 기간동안 2.30 - 4.07 ppm을 나타냈다. 한반도에서 관측된 이산화탄소 농도의 계절적 특징은 여름철에 일변화 폭이 크고 겨울철 일변화 폭이 작음을 보였다. 또한 우리나라 지역에 배출된 이산화탄소는 좁은 지역에 충분히 혼합되지 못한 상태로 존재하고 특히 중국으로부터의 영향이 있는 것으로 조사되었다. 또한 단순 선형 회귀모형과 2차 다항 회귀모형을 통해 향후 대기 중 이산화탄소 변동에 관한 4가지 시나리오가 계산되었다. 제주 고산관측소의 경우 2010년에 390.9 pp의 농도로 증가될 것이며 2015년에는 396.4-399.7 ppm에 도달할 것으로 나타났다. 안면도 지구대기감시관측소의 경우 2010년에 408.2 ppm 에 이르러 2015년에는 420 ppm을 넘을 것으로 추산된다. 제2의 온실가스 명명되는 메탄의 경우 근래 한반도에서 관측되어지는 메탄 농도는 1.9 ppm을 중심으로 이산화탄소에 비해서는 상당히 안정되어 있다. 계절별 대기의 메탄 농도는 가을철에 가장 높게 그리고 여름과 겨울 및 봄철의 순서로 농도가 나타났다. N2O의 경우 메탄과 달리 지난 4년간 약간의 상승 경향을 나타내었다. 세계기후자료센터(WDCGG)의 발간 28호에 의하면 현재 대기 중 N2O 의 농도는 연 평균 0.25%의 상승률로서 점차 상승하고 있는 것으로 보고되고 있다. CFC-11의 경우 1999년에서 2000년 사이 급격한 감소를 나타내었다가 이후 지금까지 안정적 감소 추세를 유지하고 있어 몬트리올 협약에 의한 정부의 사용규제에 대한 정책이 중요함을 보였다. 반면 CFC-12의 경우 지난 4년간 적은 감소 경향을 보였다.

What is the origin and nature of the cosmic X-ray background (here after CXRB)? Can detected discrete X-ray sources account for the CXRB? Since Giacconi et al. (1962) discovered homogeneous and isotropic cosmic X-ray background (here after CXRB), these questions have been investigated using data from several X-ray satellites but still remain technical issues such as the incompleteness of the used data. The CXRB consists of resolved and unresolved components. The resolved CXRB originates in discrete sources, while the unresolved CXRB originates in diffuse components and faint sources that are below current observational flux limits. The resolved CXRB can be directly measured from number counts of the discrete X-ray sources. In this talk, we will present the total CXRB flux density and the resolved fraction of the total CXRB using the Chandra multivelength project (ChaMP) X-ray point source catalog and the Chandra Deep Fields (CDFs) data. The ChaMP X-ray point source catalog contains ~6,800 X-ray sources detected in 149 Chandra observations covering wide sky area (~10 deg2) and provides X-ray photometric data in 8 different energy bands as well as X-ray spectral hardness ratios and colors. To quantitatively characterize the sensitivity and completeness of the ChaMP sample, we performed extensive simulations. In addition, the origin and cause of the break in the X-ray point source number counts will be discussed in this talk.

The recent development and ongoing observations of the Galaxy Evolution Explorer (GALEX) UV space telescope provide a better understanding of the star formation history in early-type galaxies. Here I will present the recent results of the GALEX observations for the early-type galaxies at 0 < z < 0.2, and discuss the UV upturn phenomenon, recent star formation, and AGN connection.

The VERA (VLBI Exploration of Radio Astrometry) project is the only 10-micro-arcsec scale astrometry observation running currently. Observation series in radio wavelength in 22GHz and 43GHz are performed with 4 radio telescopes in Japan. The aim of VERA is to measure accurate distances, their proper motions and internal motions of radio sources in Galactic star-forming regions and late-type stars. To achieve 10-micro-arcsec accuracy stably the new software with enough numerical accuracy is needed. VEDA (VERA Data Analyzer) is under development for this purpose and the fundamental library for VEDA \"CCcoda\" have been developed. In this seminar current results of VERA are introduced and the structure of CCcoda is described.

지난 5년간 국가그리드사업의 주관기관으로 그리드컴퓨팅 기술개발에 선도적 역할을 수행해 온 한국과학기술정보연구원의 그리드사업 성과 소개 및 고성능컴퓨팅 분야의 대표응용인 기후연구 분야의 연구성과와 향후 계획에 대한 소개

According to the present knowledge, a composition of interstellar absorbing matter is very complex: e.g., the already detected molecules consist of up to 13 atoms and some larger species have already been suggested. Another, perhaps most prominent, evidence of intricate processes of molecular synthesis and destruction taking place in interstellar medium is the existence of diffuse interstellar bands (DIBs) - the longest standing unsolved problem in all of spectroscopy. DIBs were discovered as long ago as in 1921 (Heger) but their carriers remain unknown despite considerable efforts of astronomers and despite a progress in observational astronomy during last 10-15 years. The list of these spectral lines or bands continues to grow, including more and more weak DIBs and reached now ~300 features. I will tell about the current state of the problem of DIBs identification.

Generation of local oscillator power at Terahertz frequencies with conventional techniques is difficult and expensive. In this thesis, I demonstrate steps towards a THz source using the photonic local oscillator technique for submillimeter astronomy. An LT-GaAs photomixer illuminated by two laser signals generates a beat frequency through photoconductive mixing, equal to the difference of two laser frequencies which can be tuned from a few hundred GHz to around a few THz. To generate two frequencies in the same laser for a photonic LO, I have investigated the use of a Ti:Sapphire ring cavity laser. To generate dual-mode operation in the multi-mode laser, two intracavity solid Fabry- Perot etalons were installed. To characterize the spectral width of the photomixing product, the beat frequency was monitored with a commercial photodetector at 34 GHz. The spectral width of the beat frequency was less than 10 kHz. The output power from the LT-GaAs photomixer was found to increase linearly with the applied bias voltage. Unexpectedly large fluctuations in the output power were measured, due to dual-mode intensity variations from the Ti:Sapphire ring cavity laser. The reasons for these power fluctuations are thermal variations of the resonator cavity, mechanical variations, dust particles, air fluctuations, and mode competition. To reduce these power fluctuations, a power stabilization system using volume holographic gratings (VHGs) was developed, which greatly reduced the power fluctuations. I helped develop a 460/810 GHz dual-channel receiver, called the First Light APEX Submillimeter Heterodyne instrument (FLASH), for the Atacama Pathfinder Experiment (APEX) telescope located at Llano de Chajnantor in Chile0s Atacama desert. Using FLASH and the APEX-2A receivers, a large number of molecular transitions toward the Long Period Variable (LPV) star IK Tau were observed. Thirty four transitions of 12 molecular species, including maser lines, were detected. To determine the spatial distribution of the 12CO(3−2) emission, mapping observations were performed. Assuming local thermodynamic equilibrium (LTE), the rotational temperatures of molecules and the molecular abundances were obtained. By comparing the abundance of the individual molecules to those reported in the literature, we found an improvement over previously available observed abundances. To constrain the physical conditions in the circumstellar envelope, emission from the SO2 and CO molecules was modeled using a Monte Carlo method. From the model fits we could estimate the molecular column density and the kinetic temperature of the envelope.

In this talk, I would like to summarize recent works on the spin of the stellar mass black holes. The possible connection between the spin of black holes and explosive phenomena, such as Gamma-ray Bursts and Hypernovae, will be discussed. Ironically, spinning black holes are the sources of the most energetic explosions in the Universe after Big-Bang.

High resolution imaging observations using Chandra X-ray Observatory revealed that there is a large population of point sources in external galaxies. Most of them are believed to be X-ray binaries in galaxies. Low Mass X-ray Binaries (LMXBs) are the subsef of X-ray binary population with low-mass (typically < 1Msun) companions indicating old stellar populations in galaxies. A study of globular clusters (GCs) in external galaxies highlighted extragalactic astronomy for last a few decades. Color distribution, radial/spatial distribution and metallicity distributition of GCs in a galaxy have been used to understand the formation and evolution of a galaxy. In a dynamical point of view GCs are probable birth-place of compact binary later to be observed as X-ray binary. I will present recent studies based on both X-ray and optical observations regarding the LMXBs in external galaxies with a particular interest on theirs connection to globular cluster system in galaxies. The possible formation process for LMXBs will be discussed.

Magnetic reconnection at the dayside magnetopause is dominantly affected by the relative orientation of the magnetic fields in the magnetosheath and magnetosphere, the relative perpendicular velocities of field lines both before and after reconnection, and the location of the minimum geomagnetic field. We have performed a high-resolution and time-dependent three dimensional MHD simulation of interaction between the solar wind and the Earth’s magnetosphere when the dipole tilt, and By and Bz components of the IMF are simultaneously included in the whole volume of the simulation box. In the recent study of Park et al. (2006) found that for positive dipole tilt (northern hemisphere is summer) and southward IMF (Bz = 5 nT, By = 5nT), the reconnection site shifts sunward and equatorward in the summer hemisphere, and moves tailward and away from equator in the winter hemisphere. The dipole tilt creates asymmetry that strongly affects the direction of the plasma flow due to reconnection. Moreover, the electric field in the northern \\\"reconnection\\\" region (antiparallel region) is 50% larger than that at the magnetic equator and twice that at the subsolar point. In present study, for the case of positive dipole tilt, and during the northward IMF (Bz = 5 nT, By = 5nT), magnetic reconnection occurs at high latitudes in the northern dusk due to antiparallel field condition in the summer hemisphere for By > 0 and creates open field lines. The open field lines which are generated in the dusk sector and their feet are on the northern ionosphere, move from dusk to dawn in the dayside magnetopause and then come back to dusk in the tail. Tail reconnection successively occurs in the slant and elevated plasma sheet. The polar cap potential in dusk cell is larger than that the dawn cell in summer hemisphere. Moreover three-cell pattern appears in the northern ionosphere. On the other hand, the negative potential is comparable to the positive potential in winter hemisphere and the distorted three-cell pattern appears in the southern ionosphere. The open-closed boundary in the winter hemisphere appears at higher latitude than that in the summer hemisphere.

In galactic disks, the one dimensional velocity dispersion of interstellar gas is observed to vary between 12-15 km/s in the central parts down to 4-6 km/s in the outer regions. Many physical mechanisms are responsible for generating interstellar turbulence. A prominent one is related to energy feedback from stars particularly in the form of supernova explosions. In this talk, I shall review a number of those mechanisms and using three-dimensional numerical simulations assess the contribution of stellar feedback in the form of supernova explosions to the observed levels of interstellar turbulence at different radii in galactic disks.

High time resolution (> 5 Hz) observations recently opened new opportunities to investigate the tiny space rocks beyond Neptune known as Kuiper Belt Objects. Extensions of such technique will become a valuable tool to discover and characterize rapid optical transients, which have never been properly studied. Another very exciting application of high speed observation is in the area of seeing-damaged image restoration. Digital image signal processing techniques combined with recently developed zero read noise imaging devices can together deliver so called super-resolution images, previously available only through space telescopes. Compared to adaptive optics of high cost and very small field of view, this approach can be an inexpensive alternative and yet cover much larger field of view, making it possible to study dense star fields and detailed galaxy structures from ground observatories.

Dark energy is one of the most mysterious objects in both cosmology and astrophysics today. We introduce and review the current dark energy projects in experimental and theoretical point of view. We also show the future projects to investigate the properties of dark energy.

None

The Hayabusa (the original code name is MUSES-C) spacecraft was designed to obtain samples from the surface of an asteroid 25143 Itokawa (1998 SF36) and return them to Earth. Itokawa is classified with S-type asteroid, and its size is 535×294×209 meters. The main objectives of the mission were to demonstrate the performance of various technical items such as autonomous navigation, sampling devices and ion engines. On 12 September 2005, the Hayabusa spacecraft successfully rendezvoused with the target asteroid Itokawa. For nearly two month before the sampling, the remote sensing observations were performed not only for the sampling site selection but also for scientific purposes. In this colloquium, we show the initial scientific results obtained by the multi-band imaging camera (AMICA) [1] [2], that is, its shape, surface topography and mineralogical composition. Unlike previously explored asteroids, this tiny asteroid is covered with numerous boulders instead of fine regolith, and shows large variations in both color and albedo [3]. In addition, we briefly recount a story we experienced in this project. Reference [1] Saito et al. 2006, Science 312, 1341-1344 [2] Yano et al. 2006, Science 312, 1350-1353 [2] Ishiguro et al. 2006, LPSC XXXVII abstract no.1533

We will outline the current status of the Seoul National University Bright Quasar Survey in Optical (SNUQSO). Bright quasars can serve as useful astrophysical tool, but not every bright quasars have been discovered to date. SNUQSO has searched for missing bright quasars in the northern hemisphere as well as at the low galactic latitude region also known as the zone of avoidance. Through our search till June 2006, we have uncovered more than a dozen new bright quasars using Boyunsan Observatory\/s 1.8m telescope. Follow-up optical imaging observations have been undertaken using the SNU\/s newly installed 4k x 4k CCD camera on the Maidanak Observatory\/s 1.5m telescope at sub-arcsec seeing. We will also review preliminary results from the optical imaging observation and the new 4k x 4k CCD camera on the Maidanak Observatory.

The Anglo-Australian Observatory (jointly funded by the UK and Australian governments) has an ongoing technology development and instrumentation program that has yielded forefront astronomical instruments used around the world (e.g. OzPoz on the VLT, 2dF on the AAT). An overview of the current instrumentation projects underway will be presented. This will cover the recently commissioned AAOmega spectrograph (a bench mounted, dual beam spectrograph fed by the fibers from the 2dF positioner), Echidna (a new technology fiber positioner for the FMOS instrument on Subaru), and WFMOS (a very wide-field MOS system for Subaru that was recently explored in a Feasibility Study for Gemini). The Instrument Science group at the AAO is actively involved in exploring and exploiting new technologies applicable to astronomical instrumentation. Studies including development of autonomous pickup relays for multi-object instruments (Starbugs), development of OH suppression in fiber optics, and continued evaluation of other ermging fiber optic technologies are presently underway. An overview of those activities will be given.

The presentation will be in three parts. The first part will be on the “origin of Type II radio bursts without the coronal mass ejections (CMEs)”. There are debates on the origin of type II bursts in the solar corona: (i) flare blast-wave driven and (ii) CME-piston driven. We have made an analysis to check whether there are any type II bursts that can be generated without CMEs. The second part will be on the “relation between the X-ray plasma ejections and type IIs”. The plasma eruptions very close to the sun are observed in X-rays using the satellite Yohkoh. We have studied in detail the association between these X-ray plasma ejections and type IIs. The final part of the presentation will be on some of the recent works in progress.

Star clusters are likely to be formed with initial angular momentum. Dynamical evolution of rotating star clusters has been investigated by the Fokker-Planck method and N-body integration. The rotation is found to accelerate the core collapse as well as the post collapse evolution. The angular momentum is transferred outward through the relaxation process. The computational details and the astrophysical implications of our recent findings will be presented.

Solid State Telescope(SST), one of the four space plasma instruments being developed for STSAT-1, is designed specifically to measure the energetic electrons with energies from 25KeV to 600KeV. With three other plasma instruments, Electro-static Analyzer(ESA), Langmuir Probe(LP), and Scientific Magnetometer(SM), SST allows in-situ detection of penetrating auroral electrons in the polar region and thus, the study of microscale physics with high time resolution data of the earth\\/s polar region that has not been previously achieved with other space missions. As our society increasingly relies on spacecraft operations in the Earth’s magnetosphere, the forecast of the space weather become more significant. Specially, the long-duration (for several days) high intensity fluxes of relativistic electrons (more than MeV energy) have been revealed to affect serious operation failure or damage to spacecrafts and satellites. So many researchers have tried to understand the dynamics of those relativistic electrons: where they come from and how they get so high energy. This work focus on the possibility of substorm injected electrons as seed electrons of relativistic electrons at the inner magnetosphere during magnetic storm time and we tested ULF and whistler chorus wave as one of acceleration mechanisms of relativistic electrons.

남극세종과학기지에서는 1990년부터 3성분 ring core fluxgate 자력계, proton 자력계를 이용하여 지자기장의 변화를 측정해오고 있다. 또한 2006년부터는 절대지자기측정도 병행하고 있다. 현재 세종기지의 지자기 자료는 인공위성과 인터넷을 통해 실시간으로 미국지질조사소로 전송되고 있다. 2007년에는 세계적 지자기 관측망인 INTERMAGNET에도 가입할 예정이다. 세종기지의 지자기 관측은 관측소가 적은 남극에서 그 희소성을 인정받고 있으며, 우주환경변화 연구에도 활용될 수 있을 것이다

Inflation is the most promising candidate to solve various cosmological problems of the big bang cosmology. We start with the motivation of inflation, and briefly review the scenario of cosmological inflation. Then we discuss some incorrectly known subjects on inflation.

Kuiper belt objects (KBOs) are a class of small bodies located beyond 30 AU from the Sun, and Centaur objects are another class of those orbiting mainly between Jupiter and Saturn. With the rapid discovery of growing number each year, over 1,000 KBOs and 60 Centaurs were known to date. Two out of three dwarf planets, which are new class by IAU resolution voted in Prague are the member of KBOs. It is widely believed that they are remnant planetesimals from the early accretion phases of the Solar System and constitute an important reservoir of primitive materials. Centaurs are often speculated to be objects in transition from the Kuiper belt, as their orbits dynamically evolve into Jupiter-family comet orbits or they get ejected from the Solar System. Photometric observations constrain the size, surface albedo, and rotational properties from its lightcurve. The lightcurve is useful to estimate the shape and lower limit of bulk density of the body. The results of several observations of KBOs and Centaurs with 1-m telescope at Wise Observatory and 200-inch telescope at Palomar Observatory will be presented. In particular, detailed results of new Centaur comet 174P/Echeclus will be given. In parallel, I will introduce the thermal model, which solves the energy equation and the mass balance equation numerically. The energy sources of young KBOs taken to be the external heat source from the early Sun and the internal heat source from radioactive species (in particular 26Al) are comparable at the typical distance of KBOs from the Sun (~ 40 AU). The models suggest that KBOs are likely to lose the ices of very volatile species during early evolution and the internal structure of KBOs is most probably not uniform but stratified with the outer layers being less altered by evolution. Additionally, cometary activity was not rare for the orbits of Centaurs and some of scattered KBOs even without radiogenic heating.