As ALMA is in full operational mode, the SMA continues to be a most valuable asset in submillimeter wavelength astronomy. In particular, for wide-field imaging, for polarization studies, and for large spectral scans, the SMA is competitive especially for the northern skies. Starting in 2017, the ASIAA invites all astronomers in the East Asian regions to join in the access to the SMA as part of an initiative within the East Asian Observatory. In this talk, we will show current capabilities and future plans for improvement in sensitivity.

기초과학 연구가 대형 연구 장비에서 생산되는 대용량 데이터를 처리하여 자연현상을 기술하는 데이터기반 연구로 패러다임이 변화하고 있다. 데이터기반 연구가 부상함에 따라 개방성이 중요해 지고 있으며 최근 OECD는 Open Data, Open Access, Open Collaboration을 통해 Open Science로 그 가치를 실현하고자 과학정책에 반영하는 활동을 하고 있다. 글로벌 대용량 실험데이터 허브센터(GSDC)는 국가 유일의 기초과학분야 데이터집약형 데이터 센터이며 CERN의 최상위 데이터센터인 WLCG Tier-1의 기능을 수행해오고 있다. 다양한 기초과학분야 지원을 강화하고 통합데이터센터로의 역할을 확대해 나가고 있는 중이다. 본 콜로퀴움에서는 GSDC에 대한 소개를 중심으로 오픈사이언스 시대의 한국의 데이터센터의 역할에 대해 소개 하고 천문연구자와 협력모델에 대해 의견을 수렴하여 GSDC 발전방향에 반영 하고자 한다

The geodetic VLBI technique is capable of measuring the Sun's gravity light deflection from distant radio sources around the whole sky. This light deflection is equivalent to the conventional gravitational delay used for reduction of geodetic VLBI data. Numerous tests based on a global set of VLBI data have shown that the parameter gamma of the post-Newtonian (PPN) approximation is equal to unity with precision of about 0.02 percent. However, the estimated accuracy is mostly dominated by the limited number observations near the Sun. I have processed 56 geodetic VLBI sessions between 1993 and 2005 when a reference radio source was observed within 5 degrees from the Sun (1662 single group delays in total) using different analysis strategies. The parameter gamma is still found to be close to unity with precision of 0.06 per cent, whereas subsets of VLBI data measured at short and long baselines produce some statistical inconsistency. In particular, at a shorter range of baseline length, the formal error is better (0.04 per cent) in spite of a less number of observations. This effect depending on baseline length may highlight some deficiency of the conventional VLBI group delay model, rather than a problem of the theory. Nonetheless, more observations near the Sun are important to improve the formal error of the PPN parameter gamma.

Stars are born with protostellar discs that during the initial stages of their formation are relatively massive, asymmetric and they are being fed with material infalling from their parent clouds. Recent ALMA observations of discs around young stars revealed the presence of gaps and spiral arms indicative of planet formation. These observations raise the exciting possibility that planets may form much faster than it has been previously thought. Therefore, their formation may be sensitive to the early properties of discs while they are still forming in collapsing molecular clouds. I will present radiative hydrodynamic simulations of self-gravitating discs forming in collapsing clouds and discuss their observational signatures. I will also discuss how giant planets that form in early phase discs evolve. Can such planets avoid fast inward migration and fast mass growth to survive until after the disc has dispersed?

영화 <인터스텔라>로 유명한 위대한 상대론적 천체물리학자 Kip Thorne의  업적을 중심으로 black hole electrodynamics의 역사와 토픽에 대하여 알아보기로 한다. 가능한 한 수식 없이 주로 그림들을 이용하여 전공자가 아니어도 들을 수 있게 눈높이를 낮춰 설명할 계획이다.

Future cosmic surveys of large scale structure and the cosmic microwave background radiation will attempt to answer questions of fundamental physics: What is the nature of dark energy? Is cosmic gravity completely described by general relativity? Can we probe the inflationary epoch through primordial gravitational waves? What are the masses and hierarchy of neutrinos and are there additional relativistic degrees of freedom? We need to develop the theoretical, computational, and technological frameworks to address the questions. I also describe the Cosmic Visions process in the US, for what might come beyond the DESI-Euclid-LSST-WFIRST era for dark energy and the CMB.

In this talk, I will introduce our new simulation suites called TIGRESS, "Three-phase ISM in Galaxies Resolving Evolution with Star formation and Supernova feedback." TIGRESS models a realistic turbulent, magnetized, multiphase ISM in galactic disks with self-consistent treatment for star formation and supernova feedback. I will discuss star formation rates and ISM properties regulated by star formation feedback and the properties of the multiphase outflows driven by SNe. I will also discuss future applications and extensions of TIGRESS.

Evolved stars in the Asymptotic Giant Branch (AGB, a crucial phase in the late evolution of most stars, including solar-type stars) present copious mass-loss processes, which finally lead to the ejection of most of the stellar mass and drive the end of that phase and the formation of planetary nebulae around white dwarf stars. During the AGB phase, the ejection is significantly isotropic, leading to wide spherical shells that are radially expanding with moderate velocities. The crucial regions to study these phenomena are the very inner circumstellar layers, where the mass loss process is actually taking place. These regions can be observed with very high resolution, better than one milliarcsecond, thanks to VLBI observations of maser lines. I will review recent studies in this field of our group, stressing the interest of simultaneous observations of different lines and of high accuracy astrometry. We have recently found a surprising very fast variability in some objects, future VLBI studies of this phenomenon will be discussed.

We have long assumed that stars form by gravitational collapse but hard evidence of infalling motions has been elusive. The Bok Globule, B335, has been the test bed for studies of simple isolated star formation. Our ALMA Cycle 1 observations of this source have revealed definitive kinematic evidence for infall in the form of redshifted absorption against the continuum source. Approximately spherical infall appears to extend inward to about 16 AU. Further studies of this and other sources will allow us to study the velocity fields of infalling matter and the transition to a rotationally supported disk, possibly through the formation of a magnetically supported pseudo-disk.

Accretion is the best model to explain the high luminosity, spectra and timing properties of AGNs and microquasars. Accretion is supposed to be the prime reason also for the ejection of jets associated with these objects. We review the phenomenology of these objects based on observations, and discuss the likely scenario to explain these phenomena. We also discuss the limitations of our understanding about these objects.

In the last two decades, the asteroid research has been significantly influenced by theoretical results obtained in the field of applied mathematics. The first step was the so called "lightcurve inversion", which is an inversion method that reconstructs a shape of an asteroid from its disk-integrated photometry. With this method, almost one thousand asteroid models have been derived so far. Its potential is much larger - it will enable us to reconstruct shapes and spin states of a significant fraction of the whole asteroid population. Together with photometry, other disk-resolved (low-resolution images, silhouettes from occultations,...) or disk-integrated data (thermal infrared flux, for example) can be analyzed and detailed models can be derived by so called "multi-modal data inversion". In this talk, I will (i) review lightcurve inversion method, (ii) highlight the main achievements accomplished in the asteroid research with lightcurve inversion, (iii) describe the role of disk-resolved data, and (iv) mention the plans and prospects for the future, in particular the cooperation within the KMTNet and LSST projects.

The acceleration of the expansion of the Universe, driven by the mysterious Dark Energy, indicates that our theory of gravity may need revision. While Einstein’s theory passes precision tests on Solar System scales, it seems to break down or require some extra component on the very largest scales. It is possible to test gravity in the Universe in the same manner as on Earth and in the Solar System, by watching test particles (galaxies, and photons) fall towards more massive objects. The theory of structure formation describes how tiny perturbations in the density of matter grow under gravitational collapse to form the structures that we see today. In this talk I will introduce the  2-degree Field Lensing Survey (2dFLenS) is a large area spectroscopic galaxy survey, describe how measurements made using the survey can be used to test gravity, and report on some tentative initial results.

The Atacama Large Millimeter/submillimeter Array (ALMA) is an aperture synthesis interferometer that currently operates from wavelengths of 3 mm to 350 microns with up to sixty-six (66) array elements, fifty-four (54) of 12-m diameter and twelve (12) of 7-m diameter. The array is located at the ALMA Array Operations Site (AOS) on the Chajnator plateau (at an altitude of about 5000 meters) in the Atacama desert in northern Chile. While the antennas and most of the hardware for the receivers are on site, array capabilities are still expanding and the observatory is ramping up towards full operations. Early science observations have been ongoing since October 2011 and today ALMA is in its fourth Cycle of Early Science observations. Many exciting, fundamental results have already been obtained from the solar system to the early universe. I will review the current status of the project, the array performance and efficiency, recent testing results, on-going development projects as well as sketching future developments that will enable ALMA to extend the frontiers of science even further. In short, I will present ALMA: Past, Present and Future.

The origin and evolution of the circumstellar disk around protostars informs the origin and evolution of planets. Only recently, have we even detected the youngest circumstellar disks, but their frequency and typical properties (i.e. mass and size) are still not known. With our new high-resolution millimeter surveys of protostars, we now have about 20 young disks with radii > 15 AU. However, these only represent less than ¼ of the population in our surveys. One possible explanation for small disks (< 15AU) in the youngest sources is magnetic braking of material at the earliest stages. In this talk, I explore the early evolution of the disk, implications for dust growth, and discuss future surveys.

Star formation covers a huge size scale. From the large giant molecular cloud complex of several tens of parsecs to the protostars at the order of solar radius, it is about 9 orders of magnitude in spatial scale. In between, we observe long filamentary dark clouds, large molecular cloud clumps, dense cloud cores that house the formation of protostars, and protostellar accretion disks. Multiply coupled highly non?linear physics are involved in the star formation process, including magnetic field, supersonic turbulence, gravity, radiation and protostellar outflow feedback. Numerical simulation has become a powerful tool to understand and connect these observational snapshots of the entire star formation process. Still, it is a challenge to simulate the entire process in a single simulation. To achieve such a long?term challenge, we need efficient adaptive codes, such as adaptive mesh refinement (AMR) code, that can manage memory usage efficiently and are highly scalable on large?scale high performance supercomputers. In this talk, I present my latest cluster formation simulation results, using our radiative?magnetohydrodynamics AMR code "ORION2", to understand (1) the intertwined filamentary structure of dark clouds, (2) the magnetic properties of the dense cloud clumps, and (3) the protostellar cluster formation in a highly supersonic turbulence region of about 4.6 parsecs in size with the highest resolution of 28 astronomical units. The simulation results match well with latest observations and provide important insight into the process of star formation at different size scales that cannot be easily obtained from observations.

눈을 들어 파란 하늘을 보자. 하늘 어디에도 “여기는 물리학의 영역이니 물리학자가 아닌 다른 사람들은 출입금지”라는 푯말이 세워진 경계는 없다. 똑 같은 파란 하늘을 보아도 인문학자가 묻는 질문은 사회과학자의 질문과 다르다. 인문학, 사회과학, 그리고 자연과학이라는 구분은 하늘에는 없다. 우리 사회에서 벌어지는 일들도 마찬가지로 경계가 없는 것이 아닐까. 인문학과 사회과학이 각각 독특한눈으로 사회를 보듯이, 물리학자도 사회를 본다. 좀 별다르게 말이다. 오늘강연에서는 사회현상을 물리학자가 어떤 눈으로 보는지를 보여주고자 한다.

과학기술사를 소개하다 보면 특정 인물을 중심으로 풀어 나가게 되기 쉽다. 특히 한국 과학기술사를 이야기할 때에는 몇몇 과학 위인, 또는 과학 ”영웅"의 이야기를 나열하는 데 머무르고 한국 과학기술사의 큰 흐름은 다루지 못한 채 지나가는 경우가 많다. 이와 같은 과학기술사 서술은 이 분야를 처음 접하는 대중의 흥미를 돋궈 독자로 끌어 들이는 데에는 유용할 수 있으나 결과적으로는 한국 과학기술사에 대한 균형잡힌 시각을 형성하는 것을 저해할 우려가 있다. 역사는 단순히 개인의 업적 기록을 모아 놓은 것이 아니라 사회의 큰 변화를 설명하는 종합적 분석이기 때문이다. 이 발표에서는 소수의 영웅 중심으로 과학기술사를 인식하는 것의 문제점은 무엇인지, 그럼에도 불구하고 계속해서 그와 같은 인식이 살아남고 복제되는 까닭은 무엇인지를 분석해 보고자 한다. 그리고 전통시대와 근현대의 유명한 과학기술 인물이 어떻게 그려지고 있는지 몇 가지 사례를 분석함으로써, 어떤 점들이 개선되어야 하며 바람직한 개선의 방향은 어떤 것인지 함께 고민해 보고자 한다.

The COSMIC Data Analysis and Archival Center (CDAAC) at the University Corporation for Atmospheric research has processed space based GNSS radio occultation, ionospheric, and other remote sensing data for nearly two decades. The CDAAC is undergoing significant development in preparation for operational data processing of the COSMIC-2 constellatio (Constellation Observing System for Meteorology, Ionosphere, and Climate). Key enhancements include geographically separated data management, processing, and archive systems, end-to-end GNSS (GPS+GLONASS) capabilities, upgraded GNSS ground infrastructure, and low latency processing and product generation. This presentation gives an overview of major enhancements, current development status, and expected milestones to launch. We also review the status of existing radio occultation missions, including COSMIC-1, Kompsat-5 (Korea Multi-Purpose Satellite), MetOp (Meteorological Operational Satellite Program of Europe), and other missions of opportunity. Finally, we discuss a project to deploy new terrestrial GNSS receivers to collect measurements and navigation data in support of radio occultation processing.

최근 십수년 간 인터넷과 디지털 기기를 포함한 IT기술의 발전으로 인해 매일 생산되는 데이터의 양이 급속하게 증가하였다. 특히 스마트폰 기술의 발전과 보급으로 인해 페이스북, 유투브 등의 소셜 미디어 사이트에는 매일 엄청난 양의 사용자 제작 컨텐츠들이 등록되고 있다. 국내의 네이버, 카카오 등 대형 포털 서비스에도 뉴스, 음악, 동영상 등의 기존 컨텐츠 데이터뿐 아니라 블로그, 카페를 포함한 다양한 사용자 제작 컨텐츠들이 폭발적으로 증가하고 있다. 이러한 컨텐츠 빅데이터는 사용자 로그와 더불어 부가가치를 창출을 위한 새로운 서비스 개발의 중요한 자원이 될 수 있다. 그러나 데이터의 양이 너무 많을 뿐 아니라 대부분이 비정형적이며 형태도 텍스트, 이미지, 음성 등으로 매우 다양하여 단순한 통계모델 기반의 패턴 마이닝으로는 한계가 존재한다. 네이버 랩스에서는 수년전부터 기계학습을 이용한 빅데이터 패턴 분석 및 응용 연구 및 이에 기반한 서비스 개발을 수행해왔으며, 특히 최근에는 딥러닝을 이용하여 음성인식, 기계번역, 이미지인식, 온라인 쇼핑, 추천 등의 분야에서 괄목할 만한 성능 개선 및 서비스 적용을 진행하였다. 본 강연에서는 기계학습의 역사와 개념에 대하여 간략하게 소개하고 특히 최근 수년간 기계학습 분야의 패러다임으로 자리잡았으며 알파고로 인해 더욱 유명해진 딥러닝에 대하여 소개한다. 그리고 네이버 랩스에서의 기계학습 특히 딥러닝을 이용한 빅데이터 분석 및 이를 응용한 서비스 사례들을 공유한다.

이번 발표는 최근에 필자가 발표한 [유라시아 역사 기행]을 소개하고, 나아가서 한국과의 관련성에 대한 다양한 사회적 현상에 대한 대담을 가질 예정이다. 한국에서는 유라시아의 고고학과 역사에 대한 관심이 높아지는 배경에는 ‘한민족의 기원’이라는 전통적인 인식이 깔려있다. 이러한 인식은 사실 일제강점기때 일본학자들에 의해 형성된 것으로, 이후 별다른 검증이 없이 최근에도 다양하게 표출되고 있다. 다년간 시베리아, 중국 북방, 몽골, 중앙아시아 등을 조사한 강연자는 실물 고고학자료를 통하여 막연한 기원지라는 인식에서 벗어나서 유라시아 고대사의 세계사적 의미를 살펴본다. 막연한 ‘유라시아 기원설’ 또는 ‘한민족 자생설’을 모두 지양하고 한반도의 사람들이 어떻게 주변지역과 교류하였고, 그를 통해 한국의 고대사가 형성되었는지를 보고자 한다. 이러한 필자의 노력은 궁극적으로 단순하게 한국 민족의 기원규명이라는 오래된 물음에 대한 합리적인 대안으로 한반도 고대문화 형성에 대한 유라시아적 의의를 밝히고자 한다.

NASA has made a significant progress in Mars missions since my last visit to KASI in June 2015. In this talk, I will discuss what NASA has accomplished last one year and how much NASA is ready for human missions to Mars. As a proposer of NASA human landing site on the surface of Mars, I will go over the criteria that NASA uses to determine or finalize the human landing site using my proposed site Gale Crater as an example. I will close my talk by examining the impact of NASA Mars missions on science, technology, engineering, STEM education, and economy as well as the significance of human presence on Mars to our future generations.

TBA

Variations in solar activity and its fluctuating irradiance have been invoked as drivers of the Earth's space environment and its climate. Although, such variations and fluctuations have been followed for decades, partly even centuries, a number of important and basic questions surrounding them remain unanswered, or controversial. This also leads to significant uncertainties in the role played by the Sun in, e.g., driving climate change. In this talk I provide an overview of our present knowledge and understanding of solar variability, covering both, commonly accepted and some of the more controversial aspects.

Quasar winds are thought to be an important feedback mechanism for transporting energy and momentum from the central engine surrounding the black hole to the host galaxy. Observational evidence of these winds can be found in Broad (>2000 km/s) Absorption Lines (BALs) from C IV, Mg II, O VI, etc. The origin of the quasar winds seems to be in close relation with their X-ray emission, which is coming from the vicinities (a few times the Schwarzschild radius) of the central black hole. Additionally, the dynamics and structure of the BAL winds can be traced in the UV-rest frame of these quasars. Therefore, in order to understand the origin and evolution of the quasar winds it is fundamental to study them using a multiwavelength approach. In this talk, I will describe different multiwavelength studies of BAL quasars, with the objective of describing the origin, structure, and dynamics of their powerful winds.

Supernova research keeps playing a major role in advancing our understanding of the universe in various ways as exemplified by the phase “seeding the elements and measuring the universe.” The hitherto results from the inaugurating KMTNet Supernova Program, which exploits the unique 24-hour continuous sky coverage of the KMTNet system, look promising for various types of research, including detecting infant supernovae of uttermost interests, new types of rapid optical transients, various variable objects, and extragalactic objects of low surface brightness. I will present interim results from the KMTNet Supernova Program alongside the visible-infrared integral-field spectrograph proposed for the WFIRST for supernova research in collaboration between the University of Toronto and Honeywell Aerospace for Canadian Space Agency and NASA.

One of the most intriguing and challenging quests of current astrophysics is to understand the physical conditions and processes that give rise to the formation of relativistic jets in AGN, production of high-energy particles, and emission of gamma-rays. Of particular interest is the question of how accretion onto super-massive black holes (SMBHs) generates such high-powered directed outflows. A combination of high-resolution very long baseline interferometry (VLBI) images with broadband flux variability measurements is a unique way to probe the emission mechanisms at the bases of jets. Our analysis of gamma-ray flux variability observed by Fermi-Large Area Telescope (LAT) along with the parsec-scale jet kinematics suggests that the gamma-ray emission has a significant correlation with the mm-VLBI core flux and the local orientation of the jet flow. In this talk, I will provide a brief overview of our current knowledge on high-energy emission from blazars. At the end of my talk, I will briefly highlight open questions and particularly promising avenues for progress.

The National Optical Astronomy Observatory (NOAO) is the USA national center for ground-based optical-infrared (OIR) astronomy. It is a Federally Funded Research and Development Center (FFRDC) sponsored by the National Science Foundation and managed by the Association of Universities for Research in Astronomy (AURA). The NOAO mission is to enable discovery for the research community-at-large through open access to world-class facilities, capabilities, services, and data products.
NOAO is deploying a new suite of research capabilities including new instruments, data products, and data services. Looking further in the future, NOAO will have major roles in Large Synoptic Survey Telescope (LSST) operations and community research support, and seeks similar roles in the Giant Magellan Telescope (GMT) and/or Thirty Meter Telescope (TMT) facilities as federal funding permits. In parallel to these research enabling activities, NOAO maintains an active program in public education, outreach, and engagement. This talk introduces NOAO and its current activities, presents recent research highlights, and summarizes current strategic initiatives that look towards 2030 and beyond.

The talk will review the largest Russian telescopes – the optical 6-m telescope and the Ratan 600 radio telescope with a ring-type 600 m aperture. Observational methods available to operate at these telescopes, as well as new instrumental studies for these methods – new CCD cameras, spectrographs for the 6-, 1-m telescopes and new radiometric systems for RATAN 600 will be discussed. The most important newest observational results obtained with these telescopes will also be touched in the talk.

Using the Jansky Very Large Array in recent years, Jun-Hui Zhao (CfA), Miller Goss (NRAO) and I have produced a 6-cm continuum map of the bright Sgr A complex that reveals far more detail than has previously been possible.  In this talk, I will describe the unanticipated results from this work, including a large population of new nonthermal filaments, and several magnetically-organized but highly distorted nonthermal filamentary stuctures that suggest the action of collimated outflows from the Galactic black hole, Sgr A*.   There is considerable evidence in both the radio map and a recent XMM X-ray survey that feedback from the Galactic black hole has a strong effect on the central tens of parsecs of the Galaxy, particularly in a direction perpendicular to the Galactic plane.  I’ll also describe new insights into the Sgr A East supernova remnant that appears to subsume Sgr A* within its volume, and shows a runaway neutron star that is the suspected remnant of the explosion.

It was only two decades ago that the reaction to the idea of measuring shape distortions of galaxies by gravitation lensing for reliably constraining cosmological parameters turned from skepticism to enthusiasm. Today, the technique called weak-lensing is routinely used to study dark matter distribution in galaxy clusters, average mass profiles of galaxies, and the large scale structures in the universe. The next decade will be the most exciting era when we to collect accurate cosmic shear data from billions of galaxy shapes. I will provide detailed introduction to gravitational lensing while highlighting some of the key milestones in the field. Ambitious future multi-billion dollar projects such as LSST, EUCLID, and WFIRST will be discussed. I will emphasize that in order to achieve their proclaimed scientific goals, substantial amounts of concerted efforts are required to overcome systematics. Finally, I will present my most recent results obtained from colliding galaxy clusters, which are often dubbed as "cosmic particle accelerators".