The astrophysics group of Korea Institute for Advanced Study consists of Prof. Changbom Park, research Prof. Juhan Kim, and six research fellows. Prof. Park organized a Korean Scientist Group (KSG) to participate in the Sloan Digital Sky Survey III that will continue through 2014. Prof. Park is also directing the KIAS Center for Advanced Computation (KIAS CAC), where massive astrophysical simulations are routinely made. Since 2011 he is leading the Survey Science Group of Korean astronomers, which has been acting as a think tank for the current and future major astronomical surveys. In 2013 he started a new project, the Korean Dark Energy Survey (KDES) project. The KDES project will focus on investigation of the physical nature of the dark energy through the upcoming surveys of large-scale structures and cosmic microwave background radiation anisotropy. The KIAS astrophysics group is planning to participate in SDSS-IV and BigBOSS surveys in 2013.
Research Prof. Juhan Kim is working together with Jihye Shin, a graduate at Kyung Hee University, on refining the cosmological hydrodynamic code to step up the calculation speed of the interaction between neighbor gas particles. And with Jieun Ahn, another student of the same university, Prof. Kim is studying the spin evolution of the simulated halos using the excursion set model. Prof. Kim is also studying the merging history of simulated halos to model the evolution of galaxies. And he is now preparing the zoom simulation for the study of the hydrodynamic evolution of galaxies in the cosmological context.
Dr. Jeong-Sun Hwang has studied the evolution of Milky Way Galaxy-like models, focusing on the effects of a gaseous halo. To do that, she has constructed galaxy models containing a gas halo with varying mass, density profile, and initial spin. Using N-body/hydrodynamic simulations, Dr. Hwang has investigated how the hot gas component affects the evolution of each galaxy model differently, in particular, on the gas dissipation/accretion and the star formation rate.
Dr. Benjamin L'Huillier has been working on designing initial conditions for running 1%-precision cosmological simulations. Dr. L'Huillier started studying the rate of galaxy interactions in cosmological simulations, as a function of the mass ratio, distance, and large-scale environment. Dr. L'Huillier is also working on a comparison of multizoom simulations with and without hydrodynamics, to see the effect of hydrodynamics on the internal properties of haloes.
Dr. Cristiano Sabiu has just submitted a paper on some previous research regarding "Constraining the Halo Occupation Distribution of Luminous Red Galaxies using the Three-point Correlation Function". Dr. Sabiu has also begun work on an "Alcock-Paczynski effect" method for determining the cosmic expansion history, leading hopefully to constraints the nature of "dark energy". Dr. Sabiu is a member of the Dark Energy Survey and more recently he has joined, through KIAS, the SDSS BOSS experiment. Within BOSS Dr. Sabiu has joined 2 projects relating to galaxy clustering and will soon propose his own project which will be a continuation of his 3PCF work.
Dr. Seokcheon Lee focuses on various statistics, which can be used for probing dark energy or modified gravity theories from Large-scale Structure formation. First, he investigates the turnover scale to probe geometrical tests. He also tries to use the linear scale power spectrum to study cosmology. Dr. Lee also studies Alcock-Paczynski like test from the two-point correlation function. This is ongoing project with Dr. Sabiu.
Dr. Sungwook E. Hong performed a series of cosmological N-body simulations with various values of cosmological constants, and studied the correlation between the value of cosmological constant and the probability of galaxies whose properties are similar to the Milky Way galaxy. As a result, the probability of Milky-Way-like galaxies becomes very small when the value of the cosmological constant is greater than ~5 times of the current value (This result may be helpful to understand the constraints of cosmological parameters for universes, which are suitable for intelligent life). In 2013, Dr. Hong is masking known objects from SDSS photometry images to prepare the study of faint objects. Also, Dr Hong will participate the development of a component of GMT (Giant Magellan Telescope) in Australia, and is planning to participate several researches, which will be performed by GMT in the future.
Dr. Xiao-Dong Li recently joined the KIAS astrophysics group and will work on testing and constraining the dark energy models from the observational data and reconstructing the dark energy properties.
- L'Huillier, B., Combes, F., Semelin, B., Mass assembly of galaxies: smooth accretion versus mergers, 2012, A&A, 544, A68
- Cristiano, S., Constraining the Halo Occupation Distribution of Luminous Red Galaxies using the Three-point Correlation Function, 2013, submitted to MNRAS (under review)
- Jee, I., Park, C., Kim, J., Choi, Y.-Y., & Kim, S. S., A Second-order Bias Model for the Logarithmic Halo Mass Density, 2012, ApJ, 753, 11
- Park, C., Choi, Y.-Y., Kim, J., Gott, J. R., & Kim, S. S., The Challenge of the Largest Structures in the Universe to Cosmology, 2012, ApJ, 759, 7
- Shin, J., Kim, S. S., Yoon, S.-J., & Kim, J., 2013, Initial Size Distribution of the Galactic Globular Cluster System, 2013, ApJ, 762, 135
- Kim, J., Park., C., Ross, G., Lee, S. M., The Top-two Biggest Simulations ever Performed for the Study of the Large-scale Structures of the Universe, 2012, Physics & High Technology, 21, 37
- Chingangbam, P. & Park, C., Residual foreground contamination in the WMAP data and bias in non-Gaussianity estimation, 2013, JCAP, 2, 31
- Hwang, J.-S., Park, C., Choi, J.-H., The initial conditions and evolution of isolated galaxy models: effects of the hot gas halo, 2013 (Feb.), JKAS, 46, 1
- Cervantes-Sodi, B., Hernandez, X., Hwang, H. S., Park, C., & Le Borgne, D., 2012, MNRAS, 426, 1606
- Chingangbam, P., Park, C., Yogendran, K. P., & van de Weygaert, R., Hot and Cold Spot Counts as Probes of Non-Gaussianity in the Cosmic Microwave Background, 2012, ApJ, 755, 122
- Pan, D. C., S. Vogeley, M. S., Hoyle, F., Choi, Y.-Y., & Park, C., Cosmic voids in Sloan Digital Sky Survey Data Release 7, 2012, MNRAS, 421, 926
- Benjamin L'Huillier, Galaxy mass assembly: mergers versus smooth accretion, IAP on Shaping galaxy evolution: interactions & feedback, Paris, France, Jan. 21-23, 2013
Presentations at Meetings
- Changbom Park, Recent Development of Dark Energy and Large-Scale Structure Studies, 한국물리학회 focus session, 대전 컨벤션 센터, Apr. 26, 2012
- Changbom Park, Large-scale Structure of the Local Universe and the LCDM Model (invited), Workshop on Ecosystems of Galaxies, USTC, Hefei, China, May 6-Jun. 2, 2012
- Changbom Park, The Challenge of the Largest Structures in the Universe to Cosmology, The 5th KIAS Workshop on Cosmology and Structure Formation, KIAS, Seoul, Oct. 30, 2012
- Changbom Park, The Challenge of the Largest Structures in the Universe to Cosmology, 2013 American Astronomical Society Meeting, Long Beach, USA, Jan. 7, 2013
- Changbom Park, SDSS4 and ngCFHT, The 2nd Survey Science Group Workshop, High-1 resort, Feb. 14, 2013
- Changbom Park, The Largest Structures in the Universe and Their Cosmological Implications, Indian Association for General Relativity and Gravity Meeting, Garhwal, India, Mar. 7, 2013
- Changbom Park, Horizon Run Cosmological N-body Simulations (invited), 3rd ICCS Manycore and Accelerator-based High-performance Scientific Computing Workshop, NAOC, Beijing, China, Mar. 26-30, 2012
- Juhan Kim, The New Horizon Run Simulations, 2012 MPA-IFT Spring Workshop on LSS, Madrid, Spain, Apr. 23-27, 2012
- Juhan Kim, Developing Cosmological Hydrosimulation Code Using CUDA, The 3rd KIAS CAC Summer School on Parallel Computing, KIAS, Jun. 26-28, 2012
- Juhan Kim & Changbom Park, The Horizon Run Simulations, The 5th KIAS Workshop on Cosmology and Structure Formation, KIAS, Oct. 29 - Nov. 04, 2012
- Juhan Kim, BigBOSS: Science Prospects and Current Status, The 2nd Survey Science Group Workshop, High-1 Resort, Feb. 13-16, 2013
- 김주한, The Biggest Cosmological Simulations, 2012 추계 계산과학공학회, 서울 EL Tower, Oct. 12, 2012
- Juhan Kim, Development of the GPU-Powered Cosmological Hydrodynamic Code, 3rd ICCS Manycore and Accelerator-based High-performance Scientific Computing Workshop and School, NAOC, Beijing, China, Mar. 28-30, 2012
- Juhan Kim, The Horizon Run Cosmological Simulations, Particle Physics and Cosmology 2012 (PPC2012), KIAS, Seoul, Nov. 05-09, 2012
- Jeong-Sun Hwang, On the initial conditions and evolution of isolated galaxy models, 2012 Workshop on Computational Sciences and Research Hub, Pusan National University, Jul. 12-14, 2012
- Jeong-Sun Hwang, On the effects of a hot gas halo in the evolution of isolated galaxy models, the 5th KIAS workshop on Cosmology and Structure Formation, KIAS, Seoul, Oct. 29-Nov. 4, 2012
- Jeong-Sun Hwang, Modeling interacting galaxies seen in galaxy surveys, the 2nd Survey Science Group Workshop, Gangwon-Province, Feb. 13-16, 2013
- Seokcheon Lee, Probing cosmic acceleration with galaxy clusters, the 5th KIAS Workshop on Cosmology and Structure Formation, KIAS, Seoul, Nov. 02, 2012
- Seokcheon Lee, Observational signals for modified gravity, Particle Physics and Cosmology 2012 (PPC2012), KIAS, Seoul, Nov. 08, 2012
- Seokcheon Lee, Dark energy probes with DES, the 2nd Survey Science Group Workshop, High-1 Resort, Gangwon-Province, Feb. 14, 2013
- Seokcheon Lee, Large scale structure for probing dark energy, AP School/Workshop, Feb. 20, 2013
- Sungwook E. Hong, LSST: Current Status (& Science Working Group in Korea), The 2nd Survey Science Group Workshop, High-1 resort, Feb. 13-16, 2013
- 5th KIAS International Workshop on Cosmology and Structure Formation
Host: Korea Institute for Advanced Study
Place: KIAS, Seoul, Korea
Date: Oct. 29 - Nov. 04, 2012
Organizer: Changbom Park
- 2nd Survey Science Group Workshop
Host: Korea Institute for Advanced Study
Place: High-1 Resort, Gangwon-Province, Korea
Date: Feb. 13-16, 2013
Organizer: Changbom Park
- 3rd ICCS Manycore and Accelerator-based High-performance Scientific Computing Workshop
Host: National Astronomical Observatories China & Korea Institute for Advanced Study
Place: NAOC, Beijing, China
Date: Mar. 28-30, 2012
Organizer: Changbom Park (as an SOC member)
- The 3rd KIAS CAC Summer School on Parallel Computing
Host: Center for Advanced Computation, Korea Institute for Advanced Study
Place: KIAS, Seoul
Date: Jun. 26-28, 2012
Organizer: Juhan Kim