Planet formation is one of the hottest topics in astronomy especially owing to the recent developments of ALMA observations of protoplanetary disks. Dust grains, which are the seeds of planets, coagulate to form larger and larger bodies, and finally form into thousand-kilometer-sized planets. One of the key observational constraints are on the dust mass and size, which directly constrain planet formation theories. In this talk, I will first review the recent observations of protoplanetary disks especially focusing on the observational constraints on dust grains. Then, I will discuss polarimetric observations of protoplanetary disks with ALMA. One of the dominant mechanisms is now believed to be the self-scattering, which allows us to constrain the dust sizes. However, the new measurements make the tension between the classical understandings of millimeter-sized dust grains and the sub-mm size dust grains with the new polarimetric constraints. I will discuss possible solutions and their impact on planet formation.

Cosmic rays go hand-in-hand with violent and energetic astrophysical conditions, and can produce observable signatures across the electromagnetic spectrum. They also play a role as an active agent in shaping the evolution of their local environment, and their effects in modifying astrophysical processes over a broad range of length-scales can be substantial. In this talk, I will present an overview of some of my recent work on modeling the effects and signatures of cosmic rays in different environments - from star-forming cores in our cosmic backyard, to circum-galactic structures and populations in the furthest reaches of the observable Universe. I will outline the impacts that cosmic rays can have on the evolution and dynamics their host system, how their astrophysical effects can manifest themselves on sub-galactic, galactic, and super-galactic scales, and how the microphysics of cosmic ray feedback may operate within interstellar and circum-galactic settings.

Magnetic field is believed to play an important role in modern Astrophysics. Dust polarization induced by aligned dust grains is widely used to study magnetic fields in various condition from diffuse medium to star-forming regions. A popular  theory of grain alignment is based on RAdiative Torques (RATs). Recently, suprathermal rotation of dust by RATs is found to induce rotational disruption of large grains into small fragments, which modifies the grain size distribution and affects the dust extinction, emission, and polarization properties. Thus, thermal dust polarization also allows us to study fundamental dust physics (alignment and disruption) and dust properties. In this talk, I will (1) present the recent development of the theory of the grain alignment and disruption by RATs to interpret the polarimetric observations toward molecular cloud w/o embedded sources and PDR regions and applications; (2) introduce the recent works on studying the role of magnetic fields in star-forming regions; (3) discuss the new effect of grain alignment and disruption on surface chemistry; and (4) discuss the future perspectives.

Strong gravitational lenses with variable sources, like supernovae (SNe), quasars (QSO), can be the next frontier in cosmic probes. Since the path differences between multiple images contain cosmological information, one can obtain crucial constraints on cosmological parameters, such as the value of Hubble constant, evolution of dark energy etc, independent of other probes by measuring the time delays (between the images). Lensed SNe and QSOs have their own advantages, e.g. lensed SNe are extremely rare as compared to lensed QSOs but the former have much better understood light curves with the time scale of a few months only. The ongoing and the upcoming time-domain surveys like ZTF, LSST, Roman will observe a lot of lenses of both kinds of sources. However, many will have the images spatially unresolved, with the observed lightcurve a superposition of time-delayed image fluxes. We investigate whether the unresolved sources can be recognized as lensed given only the lightcurve information and whether time delays can be extracted robustly. In this talk, I will discuss a few such interesting techniques that can identify the unresolved lensed systems of both source kinds (SN and QSO). Most importantly, these techniques are very much generic and, hence, do not assume any particular property of the sub-classes of the sources, such as the type of SNe, the flux variability of QSOs etc. These techniques can be very useful in detecting the lensed systems in  wide-field surveys and in measuring the time delays simultaneously to improve our understanding of the cosmos.

The feedback of massive stars and clusters, such as radiation, wind, and supernovae, accounts for most of the energy budget in galaxies. However, our understanding of massive stars and cluster formation is still poor. Statistics studies of various evolutionary stages of massive star formation are crucial to reach a comprehensive understanding of massive star and cluster formation. In order to investigate the formation of massive stars and their associated cluster, we carried out a systematic program with the interferometers (e.g., ALMA, SMA, JVLA) and single dish telescopes (e.g., IRAM-30m, SMT, CSO) toward different evolutionary stages of massive star-forming regions. Our studies yield promising clues to the formation of massive stars and protoclusters. For instance, we find that the nonthermal motions are predominantly subsonic and transonic, and gas filament widths are narrower than the previously proposed ‘quasi-universal’ 0.1 pc filament width. In this talk, I will present a detailed of our recent results using different observations from 10 pc scales to a few 0.01 pc scales, including turbulence, filament, prestellar/protostelar core,  molecular outflows, accretion, fragmentation, etc.

Solar Coronal Mass Ejections (CMEs) are large-scale eruptive events in which large amounts of plasma (up to 1013-1016 g) and magnetic field are expelled into interplanetary space at very high velocities (typ. 450 km/s, but up to 3000 km/s). When sampled in situ by a spacecraft in the interplanetary medium, they are termed Interplanetary CMEs (ICMEs). They are nowadays considered to be the major drivers of “space weather” and the associated geomagnetic activity. The detectable space weather effects on Earth appear in a broad spectrum of time and length scales and have various harmful effects for human health and for our technologies on which we are ever more dependent. Severe conditions in space can hinder or damage satellite operations as well as communication and navigation systems and can even cause power grid outages leading to a variety of socio-economic losses.  We aim at developing an advanced space weather forecasting tool, combining the MHD solar wind and CME evolution model EUHFORIA[1] with the Solar Energetic Particle (SEP) transport and acceleration model PARADISE[2]. We will first introduce EUHFORIA and PARADISE and then elaborate on our plans of to model the geo-effectiveness of impacts and mitigation to avoid (part of the) damage, including that of extreme events, related to solar eruptions, solar wind streams, and SEPs, with particular emphasis on its application to forecast Geomagnetically Induced Currents (GICs) and radiation on geospace. The novel tool will be accessible by the whole space weather community via the ESA Space Weather Service Network as it will be integrated in the Virtual Space Weather Modelling Centre (VSWMC)[3].   References [1] J. Pomoell and S. Poedts: "EUHFORIA: EUropean Heliospheric FORecasting Information Asset", J. of Space Weather and Space Climate, 8, A35 (2018). DOI: https://doi.org/10.1051/swsc/2018020 [2]N. Wijsen, “PARADISE: a model for energetic particle transport in the solar wind”. Dissertation presented in partial fulfilment of the requirements for the degree of Doctor of Science (PhD): Mathematics (KU Leuven) and the degree of Doctor of Physics (Universitat de Barcelona). April 2020. [3] S. Poedts, A. Kochanov, A. Lani, C. Scolini, C. Verbeke, S. Hosteaux, E. Chané, H. Deconinck, N. Mihalache, F. Diet, D. Heynderickx, J. De Keyser, E. De Donder, N.B. Crosby, M. Echim, L. Rodriguez, R. Vansintjan, F. Verstringe, B. Mampaey, R. Horne, S. Glauert, P. Jiggens, R. Keil, A. Glover, G. Deprez, J.-P. Luntama: "The Virtual Space Weather Modelling Centre", J. of Space Weather and Space Climate, 10, Art. 14 (2020). Open Access DOI: 10.1051/swsc/2020012

아프리카는 우리에게 멀고 위험하며 미개발된 곳으로 느껴져 발길이 잘 닫지 않는 대륙이다. 대부분 열대성 기후에 생활여건이 열악하여 오랜 식민지를 통해 자원 착취의 대상이었고 산업은 활성화되지 않았다. 그러나 최근 이 거대한 면적에서 인구가 증가하고 경제가 성장하면서 새로운 시장이 형성되는 블루오션으로 부상하고 있다. 특히 개발의 손이 미치지 않은 원시적인 풍광은 경이롭기도 하다. 점차 항공편도 증설되면서 남미보다 훨씬 접근성도 좋아져 관광이나 무역, 봉사활동 등 다양한 목적에서 아프리카에 대해 관심을 가져 볼 필요가 있다.이 강연에서는 아프리카의 개요를 간략하게 설명하고 여행하기 좋은 아프리카의 여러 국가들을 사진을 통해 소개하고자 한다.

Active galactic nuclei (AGNs) activity is expected to be closely related to the gas fuel availability and mechanism of the gas-inflow into the nuclear region. External processes such as galaxy interactions, major/minor mergers, and high-local-density environments affect not only physical quantities of their host galaxy (e.g., gas fuel) but also bar presence itself that is one of the possible gas-inflow mechanisms, and seem even to control the central gas supply to the galactic center. The entanglement between the three primary factors (environment, host properties, and bar presence) may have provoked conflicting observational results on the observed galaxy–AGN coevolution. In this talk, I would like to present the results of our work which relatively quantify the role of galactic environment and bar presence in blackhole feeding of spiral galaxies. The large volume-limited galaxy sample obtained from the Sloan Digital Sky Survey (SDSS) makes it possible to minimize the possible entangled effects and to isolate the effect of each of the three factors. We conclude that from the perspective of AGN–galaxy coevolution, a massive black hole is one of the key drivers of spiral galaxy evolution. If it is not met, a bar instability helps the evolution, and in the absence of bars, galaxy interactions/ mergers become important. In other words, in the presence of a massive central engine, the role of the two gas inflow mechanisms is reduced or almost disappears. We also find that bars in massive galaxies are very decisive in increasing AGN fractions when the host galaxies are inside clusters.

Active galactic nuclei (AGNs) activity is expected to be closely related to the gas fuel availability and mechanism of the gas-inflow into the nuclear region. External processes such as galaxy interactions, major/minor mergers, and high-local-density environments affect not only physical quantities of their host galaxy (e.g., gas fuel) but also bar presence itself that is one of the possible gas-inflow mechanisms, and seem even to control the central gas supply to the galactic center. The entanglement between the three primary factors (environment, host properties, and bar presence) may have provoked conflicting observational results on the observed galaxy–AGN coevolution. In this talk, I would like to present the results of our work which relatively quantify the role of galactic environment and bar presence in blackhole feeding of spiral galaxies. The large volume-limited galaxy sample obtained from the Sloan Digital Sky Survey (SDSS) makes it possible to minimize the possible entangled effects and to isolate the effect of each of the three factors. We conclude that from the perspective of AGN–galaxy coevolution, a massive black hole is one of the key drivers of spiral galaxy evolution. If it is not met, a bar instability helps the evolution, and in the absence of bars, galaxy interactions/ mergers become important. In other words, in the presence of a massive central engine, the role of the two gas inflow mechanisms is reduced or almost disappears. We also find that bars in massive galaxies are very decisive in increasing AGN fractions when the host galaxies are inside clusters.

Satellite observations in the solar wind (1 au, closer to the Sun (~0.3 au) and farther (~5 au)) indicate persistent existence of well-organized small-scale transient magnetic structure in a form of twisted magnetic field lines and nested flux surfaces often referred to as flux rope. This is similar to but distinguished from typical (much larger scale) magnetic clouds in the sense that the spatial or temporal scale is much smaller or shorter and its occurrence rate is far higher. Its intrinsic nature in various aspects is currently a subject of intense research. In particular, unlike the normal magnetic clouds which are ejected from the solar corona, the origin of the small-scale flux ropes has not yet been unambiguously identified. Suggestions exist that they come from small solar eruptions (ejections) or are created by magnetic reconnection in the heliospheric current sheet or turbulence in the solar wind. Frequent occurrence of this well-organized magnetic structure is a promising feature for promoting space weather prediction capability. In this talk, I will review the current understanding and major issues of this intriguing small transient flux ropes identified from various satellite observations.

Giant molecular clouds (GMCs) are the primary sites of star formation and stellar feedback in galaxies. UV radiation emitted by newborn massive stars is believed to play a key role in destroying GMCs and limiting star formation efficiency (SFE) therein, but the details of how remain elusive. In this talk, I will report on recent progress we made in modeling of star-forming GMCs with UV radiation feedback. I will overview observational constraints on the GMC lifecycle and present results of radiation (M)HD simulations, focusing on the effects of turbulence and magnetic fields. I will also briefly discuss (1) the escape of ionizing radiation and implications for diffuse ionized gas; and (2) why it is difficult to observationally validate the anti-correlation between turbulence level and star formation rate predicted by theory. I will end by talking about ongoing efforts in modeling GMC destruction with all major forms of massive star feedback (UV radiation, winds, and supernovae).

- 우리나라의 생물자원 소개(약초와 독초, 식용버섯과 독버섯, 식용곤충 등 특허) - 우리 땅에 피는 귀한 야생화 - 건강생활과 먹거리(산나물, 야생식용버섯, 신작물 등) - 귀촌하면 키워보고 싶은 약초 100가지 등 - 세상 변화의 원천은 자연(생체모방기술) - 미래는 생물자원 전쟁(나고야의정서) 등

Horizon Europe is the most ambitious program for research and innovation ever implemented. In the years 2021-2027 Horizon Europe’s beneficiaries will receive 95.5 billion Euro. The aim of this funding program is to address and solve the pending societal issues with a special focus on human resources, industrial modernization, infrastructure, and inter-regional collaboration. The goal is also for Europe to transform science leadership into worldwide leadership in entrepreneurship and innovation by 2027. The complex funding structure of Horizon Europe is organized similarly to the previous Framework Programmes and is composed of three pillars: Excellent Science; Global Challenges and European Industrial Competitiveness; and Innovative Europe. In this session special programs under Pillar 1 – the Marie Curie Sklodowska Actions (MSCA) and the European Research Council (ERC) grants for individual researchers will be especially emphasized. I will also summarize the current status of the EU – Korea collaboration in science and technology and I will examine Korea’s participation in the previous Framework Programme – Horizon 2020. 

어느 날 한 청년이 제게 물었습니다. “천문학을 하는 사람들 자살율이 높다는 데 왜 그런가요?” 제게는 금시초문인 이 질문을 그 청년은 기정사실로 전제하고 “왜”를 묻고 있더군요.너무 크고 광대한 우주에 비해 너무 작고 미약한 인간 존재를 매일 느끼는 천문학자들은 자살을 많이 한다, 라는 이야기가 있는 건 뒤늦게 알게 되었습니다.  그러면서 천문학도이던 20대에 수없이 자문하던, “이 세상 속 나의 자리는 어디인가? 내가 천문학을 하는 게 무슨 의미인가?  내가 아니어도 할 사람은 많은데..” 그 물음이 떠올랐습니다.  ‘빅히스토리’라고도 불리는 우주진화사 속에는 제가 그 청년을 다시 만난다면, 20대의 저를 다시 만난다면 들려주고 싶은 멋진 이야기 담겨있습니다. 그 이야기 한 번 들어보시겠어요?

Cosmic ray flux is an important factor to response to solar activity. Its profile shows the decreasing shape by interaction of enhanced interplanetary magnetic field structure. When the solar eruptions such as solar proton events by flares arrive at the Earth, the profile of cosmic ray flux changes to sharp increasing shape at the ground neutron monitor. The former is well known as “Forbush decrease”, while the latter is known as “Ground level enhancement”. Cosmic ray working group began neutron monitor research in the early 2000s. At first, our group focused on the interaction between solar wind/interplanetary magnetic field and cosmic ray particles. The main topics are simultaneity of Forbush decreases, anisotropy of diurnal variation, relationship between solar proton events and ground level enhancements and so on. The first of neutron monitor by our group has installed at Daejeon in October, 2011. Another neutron monitor has been installed at Jang Bogo in Antarctica in December, 2015. The observational data by both neutron monitors have registered at Neutron Monitor Database (NMDB, http://www01.nmdb.eu/data/) on April, 2018. I introduce the brief installation of neutron monitor at Jang Bogo and the scientific achievements in cosmic ray research.

Astronomy and paleontology have many things in common. In childhood, anyone is interested in the stars in the sky and can memorize the names of numerous dinosaurs. Dinosaurs 100 million years ago are buried Gobi Desert in Mongolia, which is good for stargazing because there is little rain or clouds. It is also common that amateur researchers, not professional researchers, can contribute to research field. Just as amateur astronomers discover new comet-like objects, amateur fossil hunters and even curious travelers can find dinosaurs. Most powerful hypotheses about the extinction of dinosaurs is a collaboration between astronomy and paleontology. Unlike astronomical studies about cosmic ‘space’, how are fossils that are the research subject of cosmic and earth ‘time’ studies made, how are they discovered, and how are they studied?

Alfvén waves are considered to be physically important in understanding  physical processes in the solar corona such as nonthermal heating, solar wind acceleration and  the abundance enhancement of low first-ionization-potential elements.  However, it is still not clear how these waves are excited in the lower atmosphere. To reveal their physical origin,  we  have attempted to detect Alfvénic waves in the solar chromosphere using the spectroscopic method. By analyzing  the spectral data taken by the Fast Imaging Solar Spectrograph of the 1.6 meter Goode Solar Telescope, we successfully detected the Alfvénic waves in the  superpenumbral fibrils around a sunspot. This is the first spectroscopic detection of Alfvénic waves in the solar chromosphere. These waves are found to be physically associated with the three-minute umbral oscillation.  We conclude that the Alfvénic waves excited by the slow-to-Alfvén mode conversion may prevail in the solar chromosphere. 

Shocks are ubiquitous in astrophysical environments with wide ranges of plasma parameters: the Earth’s bow shock, supernova remnants, shocks induced in relativistic jets, and ICM shocks driven by mergers of galaxy clusters. Furthermore, they come in different flavors: from non-relativistic to relativistic, from parallel to perpendicular, from subcritical to supercritical, from weak to strong shocks, and so forth. These shocks are known to produce cosmic ray (CR) particles via diffusive shock acceleration (aka Fermi first order process), which can be observed through their nonthermal emission in the EM spectrum from radio to gamma-ray. The first part of my talk will review broadly the kinetic plasma processes relevant to CR injection in collisionless shocks. Then, a variety of high energy astrophysics problems involving the CR acceleration will be discussed in the second part.

An antenna and a receiver are needed to effectively receive microwave signals from the universe. For such a receiver design, the experimental purpose and antenna characteristics should be considered. In recent radio astronomy research, there is a demand for wideband multi-channel simultaneous observation of the receiver, and the design of a Compact Tripple Band Receiver is in progress. In addition, this talk will introduce the design of a receiver for observation of CMB(Cosmic Microwave Background). The receiver for CMB observation is very different from the conventional radio telescope receiver, and the design considerations are also different. Finally, these receivers require cryogenic cooling during operation.Various technologies and design methods for cryogenic cooling of receivers will be introduced.

Cosmology is a study to understand the origin, fundamental property, and evolution of the universe. Nowadays, many observational data of galaxies have become available, and one needs large-volume numerical simulations with good quality of the spatial distribution for a fair comparison with observation data. On the other hand, since galaxies' evolution is affected by both gravitational and baryonic effects, it is nontrivial to populate galaxies only by N-body simulations. However, full hydrodynamic simulations with large volume are computationally costly. Several attempts have been proposed to overcome such difficulties, such as applying alternative galaxy assignment methods or painting baryonic feature learned from hydrodynamic simulations to N-body simulations. In this talk, I would like to introduce the MBP-galaxy abundance matching and mock galaxy catalogs of the Horizon Run 4 and Multiverse simulations, large-volume cosmological N-body simulations done by the Korean community. Also, I would like to briefly discuss how recent deep-learning techniques could help cosmological studies. 

The advent of far-infrared/submillimeter observational facilities showed that a significant fraction of star formation is placed in heavily dust-attenuated galaxies in the early Universe. Due to the nature of galaxy spectral energy distribution and the effect of K-correction, galaxies selected at submillimeter wavelengths are likely to be vigorous star-forming high-redshift galaxies. Based on their characteristics – gas-rich, large stellar mass, frequent contribution from the active galactic nuclei – they are spotlighted to show the early stage of massive galaxy evolution. In this talk, I will introduce several ongoing submillimeter extragalactic surveys, particularly focusing on the JCMT/SCUBA-2 survey on the North Ecliptic Pole region.

The lives of galaxies and their supermassive black holes (SMBH) are probably intimately linked. Although mergers are considered a promising triggering mechanism for AGN activity, numerous studies have shown that AGN hosts are no more likely to appear morphologically disturbed than inactive galaxies. To study the AGN-Merger connection, i.e., merger activity in AGNs and AGN activity in merging systems, we run a suite of high resolution zoom-in cosmological hydrodynamic simulations. These simulations are post-processed with a radiative transfer code to generate HST mock observations of redshift 0.5