1. The study about the properties of the Gould Belt Keun-Hong Park Seoul National University Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement

2. Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement 별과 우주 (Star & Universe) 1999, 11 월호

3. Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement 소백산천문대 (Sobaeksan Observatory), 2006

4. Contents Introduction Targets Result – Study 1: ISM – Study 2: Abundance Summary Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement

5. Introduction What is the Gould Belt? – Discovered by Herschel and Gould – Ongoing star forming complex 1 kpc-sized flat structure Inclined about 20° to Galactic Plane Early-type stars, open clusters, YSOs… Several Survey Projects – JCMT Legacy Survey of the Gould Belt Project – The Spitzer survey of interstellar clouds in the Gould Belt – Herschel Gould Belt Survey Project Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement

6. Introduction Similar structures are found in extra-galaxies. – M 83 (NGC 5236) – NGC 6946 The origin of the Gould Belt is not clear. – The stellar feedback effect? – Impact of a high-velocity clouds? – Impact of a dark matter clump? Find the clues for the origin in this study Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement

7. Introduction Select nearby young open clusters inside the Gould Belt and the Galactic Plane. Take the high resolution spectra of the stars in the clusters. – BOES at BOAO R ~ 45,000 – UVES POP archive data R ~ 80,000 Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement

8. Introduction Study 1: ISM – Measure E.W. of interstellar lines in the spectra of early-type stars and derive column densities. – Find interstellar clouds and their distributions. – Improve our knowledge about the LISM. Study 2: Abundance – Derive the stellar atmospheric parameters – Derive the abundance from the metal lines. Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement

9. Target Namel (°)b (°)d (pc)G.BNamel (°)b (°)d (pc)G.B Collinder 3593013249OPlatias 6205-6348X IC 46653117352OAlessi 1267-12537X Stephenson 16716390ORoslund 5710389X ASCC 123105-4250OASCC 2316814600X Collinder 69195-12400OStock 101724380X ASCC 21200-16500ONGC 22642032667X ASCC 20202-18450OCollinder 97205-2630X ASCC 18202-18500OASCC 10455-2800X Collinder 70205-17387O Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement IC 2391270-7175ONGC 6475356-5301X

10. ISM Targets – IC 2391 – NGC 6475 – Collinder 70 – IC 4665, Collinder 359, Stephenson 1, Roslund 5 Lines – Ti II (3383.76 Å) – Ca II (3933.66 Å) – Na I D (5889.95 Å, 5895.92 Å) – K I (7698.96 Å) Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement

11. ISM Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement IC 2391 15km/s

12. ISM Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement IC 2391 15km/s 23km/s

13. ISM Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement IC 2391 (~ 150 pc) Ca II Na I

14. ISM Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement NGC 6475 -3 km/s

15. ISM Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement NGC 6475 -3 km/s

16. ISM Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement NGC 6475 (~300pc) Ca II Na I

17. ISM Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement Collinder 70 25 km/s 11 km/s

18. ISM Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement IC 4665, Collinder 359 -15 km/s

19. ISM Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement Stephenson 1, Roslund 5 -15 km/s

20. Abundance Almost observed target is early-type star. – A few metal lines -> detailed analysis is impossible – Consider non-LTE effect More study is needed in this part. Non-LTE effect is ignored in follow examples. Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement StarClusterMag.(V)Sp_TypeExp. (s) HD 175538Stephenson 17.6B93600 * 2 HD 191530Roslund 57.9B9II3600 * 2

21. Abundance T, gravity : H line profile fitting Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement starHγHγHδHδHεHε T log g HD 175538 12750 4.25 HD 191530 12500 3.75

22. Abundance Mg Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement starMg lines[X/H] HD 175538 -0.50 HD 191530 0.00

23. Abundance Si Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement starSi lines[X/H] HD 175538 -0.50 HD 191530 0.00

24. Abundance O Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement starO lines[X/H] HD 175538 0.25 HD 191530 0.25

25. Summary Gould Belt is one of the most interesting structure However, origin of it is not investigated. Aim to find the clues of the origin from this study Found the ISM clouds and their distributions from the spectra of early-type spectra. Try to derive the abundance of the stars in each cluster, and to find the existence of the difference between the Gould Belt members and non- members. Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement

26. Thank You Work shop on Stars, Planets, and Life: Current Issues on Stellar Astronomy In Honor of Professor Sang-Gak Lee’s Retirement