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

Protoplanetary Disks Revealed by CARMA

Luminosity Evolution of Type Ia Supernovae and Dark Energy

Diffusive Shock Acceleration Modeling of Radio Relics in Clusters of Galaxies

Cosmological shock waves result from supersonic flow motions induced by hierarchical clustering during the large-scale structure formation in the Universe. Suprathermal particles are known to be produced via plasma interactions at collisionless shocks in tenuous plasmas and they can be further accelerated to become cosmic rays (CRs) via diffusive shock acceleration (DSA). The presence of CR electrons has been inferred from observations of diffuse radio halos and relics in some merging galaxy clusters. We have calculated the emissions from CR electrons accelerated at weak planar shocks, using time-dependent DSA simulations that include energy losses via synchrotron emission and Inverse Compton scattering. The simulated nonthermal emission are used to model the synchrotron emission from several observed radio relics.

The Cosmic Dark Energy: the current status of theory and observation

The high-z type Ia supernova magnitude-redshift relation, large-scale structure of galaxies, and the cosmic microwave background observations suggest that the expansion rate of our universe is currently under acceleration. Especially, our cosmological framework demands the presence of substantial amount of dark energy with repulsive nature like the cosmological constant. In this talk I briefly review several dark energy models that have been proposed so far and summarize the current status of dark energy model constraints with astronomical observations, together with my recent research works on this issue.

Massive (> 10,000 solar mass) young star clusters and OB associations dominate the energetic feedback from stars into the interstellar medium. They contain the most massive and luminous stars in the Galaxy, which shape their environments through winds, ionizing flux, radiation pressure, and eventually supernovae, destroying natal molecular clouds and inflating superbubbles. We develop a method, based on differential extinction of the Galactic disk, to search for massive star clusters powering most luminous star forming complexes in the Galaxy identified in the WMAP foreground maps. As results, we identify 25 candidate clusters within 40 star forming complexes having extinctions consistent with their distances. One notable example is the discovery of the Dragonfish association which is the most luminous OB association in the Galaxy powering a giant nebula at 10 kpc across the Galactic plane. Using near-infrared spectroscopy, we identify two Luminous Blue Variable candidates, one Wolf-Rayet, 15 O-type stars (including one possible runaway) out of 50 sampled stars located within the boundary of this association, which is consistent with the expected total number of OB stars greater than 400. The mass of the Dragonfish association is 100,000 solar mass, similar to that of Westerlund 1 known to be the most massive star cluster. These results, hence, offer an important opportunity to study the formation and evolution of most massive star clusters. We will discuss ongoing and planned follow-up observations of these new massive star clusters as well as the development of Wide Integral Field Infrared Spectrograph which is ideal to study them.

The night sky appears to be quiet and stable, but in reality many explosive events are happening in the universe every night. Such events are now being caught efficiently with recent transient surveys, and rapid follow-up observations are revealing exciting nature of these explosive events. In this talk, we present our follow-up observation activities of interesting transient events. These studies cover a wide range of astronomoical events including Swift J1644+57, the moment of a supermassive black hole devouring a star, the Chirstmas burst, a peculliar GRB caused by a death of two stars colliding in a common envelope, and GRB 071025, an explosive stellar death at z ~ 5 which reveals the existence of SN-dust in the early universe. In addition, we also present our work on a very nearby supernova in M101 galaxy which occured very recently. These and future transient events will continue to show us fresh views of the universe.