The astrophysics and cosmology group of Korea Institute for Advanced Study consists of prof. Changbom Park, research prof. Juhan Kim, two assistant professors, and four research fellows. Prof. Park organized a Korean Scientist Group (KSG) to participate in the Sloan Digital Sky Survey III that will continue through 2014. In December 15, 2010 Prof. Park became the director of the new KIAS computer center, Center for Advanced Computation (KIAS CAC). The newest clusters of KIAS CAC include the GPU cluster system with 96 GPUs with a peak performance of 49 Tflops. The center consists of a director, 6 professors, 2 research professors, and 4 supporting staffs.

Prof. Juhan Kim together with a student Jihye Shin is implementing gas dynamics in the GOTPM code to study the galaxy formation in the cosmological context. The smoothed particle hydrodynamics algorithm is being adopted and a new approach to simulating the star formation, supernova feedback, radiative heating and cooling mechanism are under investigation. Also they applied the individual time step method to the GOTPM to enhance the overall speedups especially for the high resolution simulations. Prof. Kim also translated the GOTPM code into the GPU language (CUDA) and obtained a speed-up factor of about 7 relative to the CPU core.

Prof. Maurice H.P.M. van Putten started a new KIAS research program on gravitational-wave physics and astronomy in light of the upcoming advanced detectors of gravitational radiation. He is the group leader on the Korean side in a Japanese-Korean collaboration on data-analysis for the Large Cryogenic Gravitational-wave Telescope (LCGT). The objectives of the LCGT are fostering international collaboration in the Asia Pacific region on gravitational-wave research and opening a new window of observations on some of the most enigmatic transient sources in the Universe, including core-collapse supernovae and gamma-ray bursts. Dr. Van Putten's model for long duration gravitational-wave bursts for the putative inner engines to some of these events is currently being implemented by LIGO for their injections and searches.

Prof. Yong-Seon Song presented new measurements of the coherent motion of galaxies based on observations of the large-scale redshift-space distortions seen in the two-dimensional two-point correlation function of Luminous Red Galaxies in Data Release Seven of the Sloan Digital Sky Survey. Dr. Song proposed new statistical method to coherently combine Baryon Acoustic Oscillation statistics (BAO) and peculiar velocity measurements exploiting decomposed density-density and velocity-velocity spectra in real space from the observed redshift distortions in redshift space. Dr. Song explored the complementarity of weak lensing and galaxy peculiar velocity measurements to better constrain modifications to General Relativity. Dr. Song, using the latest physical modeling and constrained by the most recent data, develops a phenomenological parameterized model of the contributions to intensity and polarization maps at millimeter wavelengths from external galaxies and Sunyaev-Zeldovich effects.

Dr. Graziano Rossi has combined the physics of the ellipsoidal collapse model with the excursion set theory to study the shapes of dark matter halos. In particular, he has developed an analytic approximation to the nonlinear evolution, introduced a planar representation of halo axis ratios, and provided simple physical explanations for some empirical fitting formulae obtained from numerical studies. Dr. Graziano Rossi, Dr. Prava Chingangbam and Prof. Park have extended the theoretical formalism of the excursion sets statistics to models with local primordial non-Gaussianity. They have confirmed their analytic predictions using simulated CMB full-sky non-Gaussian maps. Dr. Graziano Rossi is currently continuing his work with Prof. Park on LSS topology. The main goal is to constrain cosmological parameters and the equation of state of dark energy with the next generation of galaxy surveys, and in particular with BOSS.

Dr. Jaswant Kumar is working on the Semi-Analytic modelling of the formation and evolution of galaxies in the Universe. He is also inspecting the effects of galaxy-galaxy interactions on the properties of galaxies observed by the Sloan Digital Sky Survey.

Dr. Jeong-Sun Hwang has joined KIAS astrophysics group in September 2010. She has worked on galaxy evolution, in particular, dynamical evolution involved with galaxy-galaxy and galaxy-intergalactic medium (IGM) interactions using smoothed particle hydrodynamics (SPH) simulations. Dr. Hwang and Prof. Park have started a numerical study of interacting galaxies mainly using GADGET-2, an N-body/SPH simulation code. The study aims at investigating the effects of galaxy interactions, including distant flyby encounters, on their properties and overall galaxy evolution.

Dr. Seong-Kook Lee investigated the star-formation histories of high-redshift (3 < z < 6) star-forming galaxies using semi-analytic models of galaxy formation and the principal component analysis, and also analysed the effects of (false) assumption about the star-formation histories on the results of spectral energy distribution (SED) fitting analysis, showing that there can be significant systematic biases in the derived stellar population properties through which. Dr. Lee and Prof. Park are developing a code fitting galaxy spectra to model spectra in order to derive their physical properties.

1. Han, D.-H., Park, C., Choi, Y.-Y., Park, M.-G., The Properties of Type Ia Supernova Host Galaxies from the Sloan Digital Sky Survey, 2010, ApJ, 724, 502
2. Hwang, H. S.; Elbaz, D.; Lee, J. C.; Jeong, W.-S.; Park, C.; Lee, M. G.; Lee, H. M.' Environmental dependence of local luminous infrared galaxies, 2010 (11월), A&A, 522, 3
3. Choi, Yun-Young; Park, Changbom; Kim, Juhan; Gott, J. Richard; Weinberg, David H.; Vogeley, Michael S.; Kim, Sungsoo S.; for the SDSS Collaboration Galaxy Clustering Topology in the Sloan Digital Sky Survey Main Galaxy Sample: A Test for Galaxy Formation Models 2010 (9월), ApJS, 190, 1
4. Hwang, Ho Seong; Park, Changbom, Orbital Dependence of Galaxy Properties in Satellite Systems of Galaxies 2010 (9월), ApJ, 720, 52
5. Wang, Yougang; Park, Changbom; Hwang, Ho Seong; Chen, Xuelei, Distribution of Satellite Galaxies in High-redshift Groups, 2010, ApJ, 718, 762-767 (08/2010)
6. Park, Changbom; Kim, Young-Rae, Large-scale Structure of the Universe as a Cosmic Standard Ruler, 2010, ApJ, 715, L185-L188 (06/2010)
7. Hernández-Toledo, H. M.; Vázquez-Mata, J. A.; Martínez-Vázquez, L. A.; Choi, Yun-Young; Park, Changbom, The UNAM-KIAS Catalog of Isolated Galaxies, 2010, AJ, 139, 2525 (06/2010)
8. Park, Hyunbae; Kim, Juhan; Park, Changbom, Gravitational Potential Environment of Galaxies. I. Simulation, 2010, ApJ, 714, 207 (05/2010)
9. Lee, Joon Hyeop; Lee, Myung Gyoon; Park, Changbom; Choi, Yun-Young, The nature of the Sloan Digital Sky Survey galaxies in various classes based on morphology, colour and spectral features - III. Environments, 2010, MNRAS, 403, 1930 (04/2010)
10. Cervantes-Sodi, B.; Hernandez, X.; Park, Changbom, Clues on the origin of galactic angular momentum from looking at galaxy pairs, 2010, MNRAS, 402, 1807 (03/2010)
11. van Putten, M.H.P.M., Kanda, N., Tagoshi, H., Tatsumi, D., Masa-Katsu, F., & Della Valle, M., 2011, Prospects for true calorimetry on Kerr black holes in core-collapse supernovae and mergers, PRD, 83, 044046
12. van Putten, M.H.P.M., & Levinson, A., 2011, Relativistic Astrophysics of the Transient Universe (Cambridge University Press), accepted
13. G. Rossi, P. Chingangbam and C. Park, Statistics of the excursion sets in models with local primordial non-Gaussianity, MNRAS, 411, 1880-1896, (2011)
14. G. Rossi, P. Chingangbam and C. Park,Excursion set statistics with primordial non-Gaussianity, JKPS, Vol. 57, No. 3, pp. 563-566
15. Lee, S.-K., Ferguson, H. C., Somerville, R. S., Wiklind, T., & Giavalisco, M., The Estimation of Star Formation Rates and Stellar Population Ages of High-redshift Galaxies from Broadband Photometry, 2010, ApJ, 725, 1644 (Dec. 2010)
16. Dahlen, T., Mobasher, B., Dickinson, M., Ferguson, H. C., Giavalisco, M., Grogin, N., Guo, Y., Koekemoer, A., Lee, K.-S., Lee, S.-K., et al., A Detailed Study of Photometric Redshifts for GOODS-South Galaxies, 2010, ApJ, 724, 425 (Nov. 2010)

1. Ann, H. B., Park, C., & Choi, Y. Y. Isolated Galaxies and Isolated Satellite Systems, 2010, ASPC, 421, 15
2. Cervantes-Sodi, Bernardo; Hernandez, X.; Park, Changbom, Origin and Evolution of Galactic Spin from Looking at Galaxy Pairs 2010, AIPC, 1240, 407C
3. Vázquez-Mata, J. A.; Hernández-Toledo, H. M.; Park, Changbom; Choi, Yun-Young, A New Catalog of Isolated Galaxies 2010, IAUS, 267, 464
4. G. Rossi, Desperately seeking non-Gaussianity in the Cosmic Microwave Background, Moriond Proceedings 2010, "Cosmology"
5. G. Rossi, Primordial non-Gaussianity and excursion sets, COSMO/CosPA 2010, The University of Tokyo, Tokyo, Japan, October 1, 2010

1. Changbom Park, Environmental Effects on Galaxy Formation, ARCSEC Workshop 2011, Yongpyung, Jan. 18-20, 2011
2. Changbom Park, Computation in Astronomy - Challenges and Opportunities, 천문학회 장기발전계획 수립을 위한 워크숍, 천문학회, 서울대학교, Jan. 17, 2011
3. Changbom Park, Progresses of the Sloan Digital Sky Survey, 한국물리학회, Oct. 20-22, 2010
4. 이광호, 우종학, 이명균, 박창범, 최윤영, 황호성, 이종환, 손주비, The AGN-Bar Connection, 2010 한국천문학회 가을 학술대회, 변산 대명리조트, Oct. 7-8, 2010
5. Bernardo Cervantes-Sodi, Changbom Park, & X. Hernandes, Quantifying galactic morphological transformations in the cluster environment, 2010 한국천문학회 가을 학술대회, 변산 대명리조트, Oct. 7-8, 2010
6. Pravabati Chingangbam, & Changbom Park, Constraining non-Gaussianity with Minkowski Functionals, 2010 한국천문학회 가을 학술대회, 변산 대명리조트, Oct. 7-8, 2010
7. 안경진, 홍성욱, 박창범, 김주한, Ilian T. Iliev, & G. Mellema, 2D genus topology of 21-cm differential brightness temperature during cosmic reionization, 2010 한국천문학회 가을 학술대회, 변산 대명리조트, Oct. 7-8, 2010
8. 박창범, Rien van de Weygaert, W. Hellwing, & 김주한, Simulation of the SDSS Survey Region of the Universe, 2010 한국천문학회 가을 학술대회, 변산 대명리조트, Oct. 7-8, 2010
9. Changbom Park, Galaxy Clustering Topology: A Galaxy Formation Model Test, Workshop on Redshift Survey & Large-Scale Structure, National Astronomical Observatory of China, Jun. 24, 2010
10. Changbom Park, Topology of Large Scale Structure (three invited lectures), Summer School on Redshift Survey & Large-Scale Structure, NAOC, Beijing, China, Jun. 13-23, 2010
11. Changbom Park, Large-Scale Structure Topology as a Cosmic Ruler, CITA@25 Bond@60 Workshop, Canadian Institute for Theoretical Astrophysics, Univ. of Toronto, Toronto, Canada, May 13-16, 2010
12. 이광호, 박창범, 이명균, 최윤영, Dependence of Barredness of Late-Type Galaxies on Galaxy Properties and Environment, 2010 한국천문학회 봄 학술대회, 경희대학교, Apr. 8-9, 2010
13. 최윤영, 박창범, 김주한, Weinberg, D. H., 김성수, Gott, J. R., Vogeley, M. S., Topology of Galaxy Clustering in the Sloan Digital Sky Survey Main Galaxy Sample: a Test for Galaxy Formation Models, 2010 한국천문학회 봄 학술대회, 경희대학교, Apr. 8-9, 2010
14. Juhan Kim, How to Build a Parallel Computer in a Lab, The 1st KIAS CAC Winter School on Parallel Computing, KIAS, Seoul, Feb. 22-23, 2011
15. Juhan Kim & Changbom Park, Cosmological Simulation Powered by CUDA, NIMS, Daejeon, 2010
16. Juhan Kim, KIAS GPU 컴퓨팅 시스템 소개, Korea Supercomputing Conference 2010, Seoul, Dec. 6-7, 2010
17. Yong-Seon Song, New cosmological probe of dark energy, Nordita The return of de Sitter workshop, 2011-03
18. Yong-Seon Song, The case of wide and deep survey. 서울대학교 한국 천문학회 중장기 발전계획 워크샵, 2011-01
19. Yong-Seon Song, Cosmological implication of coherent motion measurements / Brisbane-Queensland University Cosmic Co-Motion Workshop, 2011-10
20. Yong-Seon Song, Decomposition of coherent motions from redshift survey / Brisbane-Queensland University Cosmic Co-Motion Workshop, 2011-10
21. Yong-Seon Song, Dark sides of universe, Daejon QGC 2010
22. Yong-Seon Song, Nature of dark energy, APCTP Dark sides of universe, 2010-08
23. Jeong-Sun Hwang, Models of Arp 285: The Formation of "Beads on a String" in the Accretion Tail, The 4th KIAS Workshop on Cosmology and Structure Formation, KIAS, Seoul, Nov. 3-7, 2010
24. Lee, S.-K., SED-fitting Analysis of High-redshift Star-forming Galaxies: Effects of Assumed Star-formation Histories, The 4th KIAS workshop on Cosmology and Structure Formation, KIAS, Seoul, Nov. 3-7, 2010
25. Graziano Rossi, "CMB non-Gaussianities: statistical methods and their applications", Allahabad, India - December 16, 2010 - Meeting on ``Primordial features and non-Gaussianities at the Harish-Chandra Research Institute (HRI)
26. Graziano Rossi, "Non-Gaussianities in the CMB", Seoul, South Korea - November 4, 2010 - The ``4th KIAS Workshop on Cosmology and Structure Formation at KIAS
27. Graziano Rossi, "Testing the expansion of the Universe with the GMT", Seoul, South Korea - October 5, 2010 - The ``GMT2010: Opening New Frontiers with the Giant Magellan Telescope at Seoul National University
28. Graziano Rossi, "Photometric redshifts, convolution and deconvolution techniques", Beijing, China - June 23, 2010 - Workshop on ``Redshift Survey and Large Scale Structure at the National Astronomical Observatory
29. Graziano Rossi, "Non-Gaussianity of the CMB and excursion sets", Toronto, Canada - May 14, 2010 - CITA@25 and BOND@60 - Conference for the 25th Anniversary of the Canadian Institute for Theoretical Astrophysics (CITA)
30. Graziano Rossi, "CMB excursion sets and primordial non-Gaussianity", La Thuile, Aosta Valley, Italy - March 16, 2010 - XLVth Rencontres de Moriond, ``Cosmology: the new challenges, Hotel Planibel - Contributed talk in the ``CMB/Polarization section

1. Changbom Park, 천문기록에 담긴 한국사의 수수께끼, 참여불교 리더스포럼, 만해NGO교육센터, Dec. 7, 2010
2. Changbom Park, 21세기 과학이 본 우주의 실체, 경기과학고, Dec. 6, 2010
3. Changbom Park, 21세기 과학이 본 우주의 실체, 인천시민의 과학 나들이, 인천 미추홀 도서관, Nov. 13, 2010
4. Changbom Park, 하늘의 과학, 경기도 박물관, Oct. 13, 2010
5. Changbom Park, Effects of Large-Scale Background and Galaxy-Galaxy Interactions on Galaxy Properties, Kapteyn Institute Colloquium, Sept. 20, 2010
6. Changbom Park, Astronomical Tradition in Korea and Modern Applications, Kapteyn Institute Seminar, Sept. 2, 2010
7. Juhan Kim, Tutorial on the GPU Cluster, KIAS, Seoul, Jan. 31, 2011
8. van Putten, M.H.P.M., February 7 2011, ``Eyes on e," KIAS Lecture to Science High School students, KIAS, Seoul
9. Yong-Seon Song, The future of large scale structure formation, 서울대학교 콜로퀴엄, 2011-03
10. Yong-Seon Song, Modeling Extragalactic Foregrounds and Secondaries for Unbiased Estimation of Cosmological Parameters From Primary CMB Anisotropy, 교토대학교 세미나, 2011-03
11. Yong-Seon Song, Lectures of dark energy II - GR test, Stockholm Winter school on cosmic acceleration, 2011-03
12. Yong-Seon Song, Lectures of dark energy I - Classification of dark energy models / Stockholm Winter on cosmic acceleration, 2011-03
13. Yong-Seon Song, Dark energy special lectures / KIAS KIAS conference, 2010-11
14. Yong-Seon Song, Cosmological implication of measuring coherent motions / KASI KASI Colloquium, 2010-11
15. Yong-Seon Song, 현대 우주론의 진화와 미래 / 경북대학교 경북대학교 콜로키엄, 2010-09
16. Graziano Rossi, "Cosmological challenges in the new decade: non-Gaussianity, LSS topology, and photometric redshift surveys", Milano, Italy - January 28, 2011 - INAF, Osservatorio Astronomico di Merate
17. Graziano Rossi, "Statistical techniques for detecting primordial non-Gaussianity", Seoul, South Korea - August 19, 2010 - APCTP Mini Workshop on ``Recent progresses in Dark-Universe and Astrophysics
18. Graziano Rossi, "Non-Gaussianity: a pedagogical review", Pohang, South Korea - May 7, 2010 - APCTP-IEU ``Focus Program on Cosmology and Fundamental Physics - Postech Headquarter
19. Jeong-Sun Hwang, Models of Galaxy Interactions in Stephan's Quintet, KISTI, Daejeon, Oct. 29, 2010
20. Lee, S.-K., Physical Properties and Star-formation Histories of High-redshift Star-forming Galaxies, SNU Colloquium, Seoul National University, Seoul, Sep. 30, 2010

1. Meeting: Summer School on Redshift Survey & Large-Scale Structure
   Host: National Astronomical Observatory of China
   Place: NAOC, Beijing, China Date: Jun. 13-23, 2010
   Organizer: Changbom Park (SOC member)
   http://cosmology.bao.ac.cn/~summer2010/index.html
2. Meeting: The 4th KIAS Workshop on COSMOLOGY AND STRUCTURE FORMATION
   Host: KIAS
   Place: KIAS, Seoul, Korea
   Date: Nov. 4-7, 2010
   Organizer: Changbom Park (Host)
   http://conf.kias.re.kr/cosmology10/
3. Meeting: Workshop for Next Generation Supercomputing - GPU Applications for Astrophysical Problems
   Host: KIAS, NIMS
   Place: NIMS
   Date: Dec. 8-10, 2010
   Organizer: Changbom Park (SOC member)
   http://csm.nims.re.kr/gputoast2010/GPUToAst2010/GPUToAst2010.html
4. Meeting: EAYAM (East Asian Young Astronomers Meeting) 2011
   Host: KYAM
   Place: Dae Myeong, Jeju, Korea
   Date: Feb. 13-18, 2011
   Organizer: Changbom Park (SOC Chair)
   http://ikha.or.kr/eayam2011