1. 講義資料 2 京都大学大学院 2011 年 10 月 3-5 日 特別講義「電波天文学」 福井康雄 名古屋大学大学院 1

2. Part I GMCs in the LMC 2

3. Magellanic Clouds  D=50 kpc (one of the nearest)  Different environment from the MW.  High gas-dust ratio  Low metallicity  Active star formation  Massive star formation  Young populous clusters The Large Magellanic Cloud The Small Magellanic Cloud 3

4. 4

5. 5 ~ 5 Myr ~ 10 Myr ~ 7 Myr Only HII regions 88 clouds (51 %) Clusters and HII regions 39 clouds (23 %) Only clusters ~ 5 Myr O-Starless 44 clouds(32 %) 150 pc Type I Type II Type III 3 Types of GMCs in the LMC

6. 6 NN159 CO 3-2/1-0 vs. Ha

7. 30Dor No.1 N206 No.1 GMC225 No.1 X CO = 3×10 -6 ； solid ： R 3-2/1-0,clump ； broken ： R 12/13 ＞ 50K, 10 3-5 cm -3 (warm, dense) ＞ 30K, 10 3 cm -3 (warm. diffuse) 15-40K, 10 3 cm -3 (cool, diffuse) 7

8. CO(J=1-0)CO(J=3-2) CO(J=4-3) ASTEMopra NANTEN2 Spitzer(8, 24  m) (Meixner et al.2006) +NANTEN2 CO (4-3) N159S N159W N159E N159 region in the LMC NANTEN2 CO J=4-3 observations Mizuno et al. 2010 8

9. 9 Results ： N159W –Temperature 72 +3 -9 (K) –Density 4.0 +0.0 -0.0 ×10 3 (cm -3 ) 1  level

10. 10 Results ： N159S –Temperature 31 +8 -9 (K) –Density 1.6 +0.4 -0.3 ×10 3 (cm -3 )

11. 11 Star formation Contours ： 12CO(J=4-3) Image ： optical B, V, H , O III (ESO)

12. 12 イメージ： HI コントア： 12 CO ( コントアレベル １２ K から 3.6K ごと )

13. 13 “3-D” comparison of CO and HI in the LMC Fukui et al. 2009 Previous studies: 2D projection and larger spatial averaging, 100pc ~1kpc, e.g., Schmidt law Present study: local property of star forming GMC and HI at ~50pc scales X-Y and Velocity: 3-D datacube of CO NANTEN and HI ATCA (Kim et al.2003) Resolution: 40pc x 1.7 km/s HI CO

14. 14

15. 15 SMC LMC

16. 16 CO HI GMC grows by collecting HI [10 6 Mo per 10 Myr] Mass flow rate; dM/dt~0.1 solar mass/yr dM/dt=4  R 2 n(HI) V R~70pc n(HI)~10 cm -3 V~7 km/s

17. M33 Correlation with HI Deul & van der Hulst (1987) 17

18. 18 Molecular clouds and star formation Ionized region High excited region Cold molecular gas N159S ＊ No massive star formation ＊ cold N159W ＊ massive star formation ＊ Ionized gas ＋ ＊ pre star forming region N159E ＊ Massive star formation ＊ extended ionized gas

19. Part II Westerlund 2, case of super-star cluster M20, isolated high mass star Collision-induced star formation 19

20. Genzel et al. 2003 Super star cluster in the MW Figer et al. 1999 0.4[pc] 0.6[pc] 1.2[pc] Genzel et al. 2003 Figer et al. 1999 Central Cluster Arches ClusterQuintuplet Cluster O stars are rare in the MW It is important to study nearby young and rich cluster but, only five super star clusters in the MW 20

21. Smith et al. 2000 blue: [OIII] green: Hα red: [SII] Car GMC (Yonekura et al. 2005)

22. Pre-cluster cloud core; requirements Compact, dense, massive cores; mass 10^4Mo – 10^5Mo, radius 1pc These are rare in the solar vicinity, because a dense core of 10^3Mo quickly forms a cluster and is dissipated e.g.,  Carnae We need non-star forming dense gas [magnetic field, strong turbulence, etc.] Case 1: quick formation of cores by shocks at 10- 100km/s and/or Case 2: slow formation (3km s-1) but with gas of low-star formation efficiency 22

23. Total mass of star: 4500 M sun (Rauw et al. 2007) Age ： 2-3 Myr (Piatti et al. 1998) O type star ： 12 (Rauw et al. 2007) Wolf-Rayet (WRs) star ： 2 (Rauw et al. 2007) Distance:2.8 kpc (Ascenso et al.2007) 4.3 ± 1.4 kpc (Furukawa et al.2009) 8.3 ± 1.6 kpc (Rauw et al. 2007) Spitzer IRAC 3.6, 4.5, 5.8, 8.0  m HESS J1023-575 Westerlund 2(Wd2) HII region RCW 49 HII region associated with the cluster (Churchwell et al. 2004) YSOs: 300 (Whitney et al. 2004) 23

24. Cloud-cloud collision scenario A collision between two clouds trigger the star formation of the central O7.5 star (Torii et al. 2011) Same scenario as Westerlund 2 (Furukawa+09; Ohama+10) 30km/s 24

25. Distribution of line intensity ratio Ratio is high near the cluster image: integrated intensity, cont.:CO(2-1) Red cross ： Wd2 Ratio 12 CO2-1/ 12 CO1-0Ratio 12 CO2-1/ 13 CO2-1 1.0 0 1.5 0.5 15 5 0 10 2.0 25

26. LVG Analysis Gray ： error range15% line ： 12 CO2-1/ 12 CO1-0 wiggle line: 12 CO2-1/ 13 CO2-1 High Temp. Low Temp. Estimation of temperature and density by using the LVG analysis including 13CO(J=2-1) 26

27. Temperature distribution of the molecular clouds Image: Temperature, cont.: 12 CO(2-1) red cross ： Wd2 Suggesting gas is heated by the raditation from the cluster. 4 km/s Cloud16 km/s Cloud 27

28. Temperature with distance from Wd2 高温 → 分子雲全体が HII 領域に付随してい る 星団周辺で高温 星団から離れるにつれ て 減少している。 Molecular clouds are associated with Wd2 and RCW 49 Ohama, Furukawa et al. 2010 28

29. The Trifid Nebula (M20, NGC6514) D= 1.7-2.7 kpc (Lynds & Oneil 85; Cambr´esy+11) Open cluster – ~500 Mo HII region （ ~0.3Myrs, Cernicharo+98 ） Central O star （ HD164492 ） 2 nd generation star formation （ e.g., Cernicharo+98; Rho+01; Lefloch+08 ） 29

30. The Trifid Nebula (M20, NGC6514) (Rho+08) D= 1.7-2.7 kpc (Lynds & Oneil 85; Cambr´esy+11) Open cluster – ~500 Mo HII region （ ~0.3Myrs, Cernicharo+98 ） Central O star （ HD164492 ） 2 nd generation star formation （ e.g., Cernicharo+98; Rho+01; Lefloch+08 ） 30

31. NANTEN2 12 CO J=2-1 (Torii et al. 2011) 31

32. CO(J=2-1) + Spitzer 8um (Rho+08) 32

33. Velocity distribution 33

34. CO2-1/CO1-0 ratio 34

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37. (Dobashi+01) M20 37