The spectral energy distribution of the light emitted from galaxies across the electromagnetic spectrum contains a myriad of details about the stellar, nebular and dust components of galaxies. In this talk, I present a new approach to assess the relative merits of different types of observations to constrain galaxy physical parameters. To this goal, we build a comprehensive library of galaxy spectral energy distributions by combining the semi-analytic post-treatment of a large cosmological simulation with state-of-the-art models of the stellar and nebular emission and attenuation by dust. A main novelty of our approach is the ability to interpret simultaneously the stellar and nebular emission from galaxies, even at low spectral resolution. We first analyze the medium-resolution, rest-frame optical spectra of a sample of ~ 13,000 nearby star-forming galaxies extracted from the Sloan Digital Sky Survey. We then rely on our sophisticated and physically motivated models to derive predictions on the star formation histories of blue galaxies at redshift z<1.4. We also apply our approach to the analysis of combined photometric and spectroscopic observations of a sample of galaxies at redshifts between 1 and 3. Finally, we use our approach to simulate observations of primeval galaxies with the NIRSpec instrument onboard the future James Webb Space Telescope. The approach developed in this thesis can be used to extract valuable information from any kind of galaxy observation across the wavelength range covered by spectral evolution models as well as to plan for future galaxy observations.

The National Astronomical Observatories, Chinese Academy of Science (NAOC), has started building the largest antenna in the world. Known as FAST, the Five-hundredmeter Aperture Spherical radio Telescope is a Chinese mega-science project funded by the National Development and Reform Commission (NDRC). FAST also represents part of Chinese contribution to the international efforts to build the square kilometer array (SKA). Upon its finishing around September of 2016, FAST will be the most sensitive single-dish radio telescope in the low frequency radio bands between 70 MHz and 3 GHz. I will review the design specifications of FAST, its expected capabilities, and its main scientific aspirations. In anticipation of the likely limitations at the initial stages of operation, I will also discuss the considerations and opportunities for astronomical discoveries in the "early science" phase of FAST.

[Fe II] forbidden lines are among the brightest emission lines in NIR band. They have been observed toward diverse types of astronomical sources, from nearby star-forming regions to active galactic nuclei. These NIR [Fe II] lines are particularly strong in shock-heated dense atomic gas, which makes them a shock tracer. Numerous emission lines from the transitions among 16 ground levels of Fe II provide useful diagnostics of physical conditions in shocked gas. In this talk, I will first review the physics of NIR [Fe II] forbidden lines, and then I will present some astrophysical applications regarding interstellar shocks, supernova remnants, and starburst galaxies.

Many intermediate- and high-mass stars are in binary or multiple systems, but the binary formation mechanisms are still uncertain. We have performed a search for FGK spectral type companions to A and B stars, which may have formed through instabilities in the protostellar disk in a scaled-up version of massive planet formation theories. We do so by searching directly for the spectral lines of the low-mass star using high signal-to-noise ratio and high resolution spectroscopy. I will describe a search through the VLT/CRIRES archive for such companions. I will also briefly describe how a similar technique using the near-infrared spectrograph IGRINS should be able to detect the thermal emission from a massive planet orbiting a sun-like star.

Hierarchical structure formation scenario inevitably leads to the formation of binary supermassive black holes (SMBHs) on a subparsec scale in merged galactic nuclei. However, to date there has been no unambiguous detection of such systems. In this talk, I propose how binary SMBHs merge and a feasible method to detect binary SMBHs with a triple disk, which consists of an accretion disk around each black hole and a circumbinary disk surrounding them. The talk is divided into three parts: First, the evolution of binary SMBHs is described based on the triple disk model. Next, the number of binary SMBHs in nearby active galactic nuclei is discussed. Finally, characteristic signals from such a binary black-hole system are studied by Smoothed Particle Hydrodynamics simulations.The detectability with next generation all-sky X-ray surveys such as extended Roentgen Survey with an Imaging Telescope Array is also briefly discussed.

Luminous high-redshift Ly-alpha blobs (LABS), often also known as Ly-alpha 'nebulae', ‘halos’ or ‘fuzz’ in the literature, promise to yield important insights into the physics of massive galaxy formation. As prodigious sources of HI Ly-alpha photons, with ~10-100 kpc spatial extents, they provide an efficient way to select distant galaxies (or proto-galaxies) expected to be undergoing significant mass-assembly. In this talk, I will present results from a recently accepted paper in which we used long slit spectroscopy from GTC+OSIRIS to examine the geometry, powering, and origin of the LAB and an absorption line system associated with a radio-loud quasar at z=2.54. I will also discuss some interesting new results from long-slit spectropolarimetry of LABs associated with z>2 radio galaxies, and their related continuum structures.

Recent observations of strikingly well-defined spirals around asymptotic giant branch (AGB) stars point to the importance of the presence of binary companions to explain the circumstellar properties of such evolved stars. Binary motion introduces directional dependence of an AGB wind, creating an elongated spiral pattern in the plane of the sky. I will show the use of the elongated spiral pattern to constrain key binary quantities (i.e., inclination of the orbital plane, orbital period, companion mass, and binary mass ratio). To determine the AGB component's mass, it is required to obtain the kinematic information of the circumstellar pattern from a molecular line observation with the high resolution and sensitivity of current interferometers, e.g., ALMA, EVLA, and SMA.

The Submillimeter Array (SMA) is a pioneering radio interferometer dedicated to the observation of the submillimeter sky at angular resolutions of 1 to 30 arc seconds. Since its full scale operation 10 years ago, the SMA has made important contributions to astrophysics from planetary science, star formation to submillimeter galaxies. The SMA is also the de facto pre-cursor of the more powerful ALMA, for which it has paved the way and has laid down a strong technological foundation. As ALMA moves into full scale science operation over the next few years, the SMA is re-positioning itself by making way for new capabilities. The key upgrade under planning is a new wideband receiving system, which will have instantaneous sky coverage of up to 72 GHz. To make this possible, new ultra-wideband SIS receivers and backend electronics running at blazing speeds have to be developed. Running in parallel with the SMA wideband upgrade is the new Greenland telescope initiative. The Smithsonian Observatory, in collaboration with ASIAA, Taiwan, is planning to move a 12-meter telescope (an ALMA prototype dish) to Greenland. While the primary mission of the project is to provide a northern anchor point for the submillimeter VLBI campaign to observe the massive black hole in M87, plans are being made to equip the Greenland telescope with diverse instrumentation ranging from THz multi-beam receivers to multi-color wide-field bolometric camera. We expect that all these technological developments will further push the frontiers of submillimeter astronomy.

I will present high-resolution rotation curves and mass models of neaby (< 10 Mpc) dwarf galaxies culled from LITTLE THINGS. The high-resolution HI observations ( 6" angular; < 2.6 km/s velocity resolution) of LITTLE THINGS enable us to derive reliable rotation curves of the galaxies in a homogeneous and consistent manner. The rotation curves are combined with Spitzer archival 3.6 micron and ancillary optical UBV images to construct mass models. The high quality multi-wavelength dataset significantly reduces observational uncertainties and thus allows us to examine in detail the dark matter distribution in the galaxies. We compare the central dark matter distributions of the LITTLE THINGS sample galaxies with those of dwarf galaxies from The HI Nearby Galaxy Survey (THINGS). From this, we find that they are consistent with each other in terms of (1) the rotation curve shape, showing a linear increase in the inner regions, and (2) a shallow slope of the mass density in the inner parts, resulting in dark matter halos characterised by a core. This is in contrast with classical dark-matter-only cosmological simulations, which predict a steep rotation curve in the central region and steep inner slope of the dark matter density profiles. Instead, our results are more in line with shallower slopes found in LambdaCDM simulations of dwarf galaxies in which the effect of baryonic feedback processes is included. If time allows, I will finish the talk with the latest progress on ASKAP.

Although the effects of ram pressure stripping on galaxies appear to be well understood, the effects of magnetic fields in the interstellar medium and intergalactic medium have not been well examined. I will present new results from magnetohydrodynamics simulations of ram pressure stripping on early-type galaxies with their turbulent weakly-magnetized ISM and weakly-magnetized ICM.

Today, astrophysical research in Kazakhstan is being developed either in theoretical and observational aspects. In particular, both computational astrophysics and stellar dynamics are gaining more momentum due to international collaboration. Meanwhile, a couple of main projects in observational research are construction of a new 3.6 meter optical-IR ground-based telescope, and the participation in the international space project called "World Space Observatory ? Ultraviolet" (WSO-UV).

The recent success of Kepler space telescope in detecting several circumbinary planets combined with many detections of circumprimary planets during the past decade have firmly indicated that planet formation in and around binary star systems is robust and planets of variety of types and sizes can exist in different orbits in these complex environments. The orbital diversity of these objects raises many challenging questions in regard to the formation, possible migration, and dynamical evolution of these bodies. For instance, almost all currently known circumbinary planets are Jovian type and orbit their host binaries in the inner edges of their stability regions. Also, radial velocity searches for circumprimary planets seem to indicate that binaries with separations smaller than 20 AU cannot host planets. On the other hand, models of terrestrial/habitable planet formation in and around binaries suggest that Earth-sized planets with substantial amount of water can exist in such systems implying that habitable planet-hosting binary star systems exist and their detection is only a matter of time. I will review the current state of research on the observation of planets in binary star system using RV, ETV, and transit photometry, and discuss the theoretical models of their formation, dynamical evolution, and their habitability.

New Insights into the Earliest Phases of Low-Mass Star Formation

Gravitational waves from spinning binary sources

The GMT-CfA, Carnegie, Catolica, Chicago Large Earth Finder (G-CLEF): A General-Purpose Optical Echelle Spectrograph for the GMT with Precision Radial Velocity Capability

Circumstellar Disk Evolution: Accretion, Transition Disks, & Planet Formation

Ultra-Precision Machining of Aspheric Molds for X-Ray Telescopes after ASTRO-H

The ASTRO-H project

Challenge to Asteroid Space Missions: From Hayabusa to Hayabusa 2

VLBI multi-epoch water maser observations toward star-forming regions

Exploring the Outer Solar System from Neptune to the Oort Cloud using Occultations of Stars

Gas and Galaxy Evolution in the Local Universe

국제우주정거장(ISS) 활용 우주실험

Cosmic Near-Infrared Background from the Early Universe: Case Study for MIRIS

High Resolution Stellar Spectroscopic Studies

A deeper look on thick discs using data from the Spitzer Survey of Stellar Structure in Galaxies (S4G)

Exploring the Terahertz Universe: Capabilities and Early results from the Herschel Space Observatory

Chasing Down Cosmic Acceleration

On the formation of massive galaxies

삼성탈레스의 광전자분야 연구내용소개