1. 渦状銀河における GMC の進化と星形 成 Evolution of GMCs and star formation in spiral galaxies Nario Kuno Nobeyama Radio Observatory 1.NRO M33 All-Disk Survey of Giant Molecular Clouds (NRO MAGiC) 2.Preliminary results of ALMA cycle 0 observations of M83 3.CO Galactic Plane Survey by NRO 45-m telescope

2. Collaborators T. Tosaki 1, S.Onodera 2, R. Miura 3, K. Muraoka 5, S. Komugi 3, T. Sawada 3, K. Nakanishi 3, K. Kohno 4, H. Kaneko 6, A. Hirota 7, N. Arimoto 7, H. Nakanisi 8, R. Kawabe 3, F. Egusa 9, K. Wada 8 1 Joetsu University of Education 2 Meisei university 3 Chile observatory, NAOJ 4 University of Tokyo 5 Osaka Prefecture University 6 Tsukuba university, 7 NAOJ 8 Kagoshima University 9 ISAS

3. Introduction Cycle of matter in galaxies – Evolution of molecular clouds (from atomic gas to dense gas) are one of the main themes of radio astronomy

4. Observations of GMCs in nearby galaxies – LMC: Kawamura et al. 2009, Hughes et al. 2010… – M33: Rosolowsky et al. 2007, Gratier et al. 2012… – M51: Koda et al. 2011, Egusa et al. 2011… – IC10: Leroy et al. 2006 – M31: Rosolowsky et al. 2007 Scientific objectives: Basic properties of GMCs （ mass, size, … ） Evolution of ISM ⇔ star formation process – GMC formation → dense gas → stars → destruction of GMCs GMCs in M33 and M83

5. 1. NRO M33 All-Disk Survey of Giant Molecular Clouds (NRO MAGiC) Close to our Galaxy (D = 840 kpc) each GMC can be resolved (NRO 45m resolution ： 20"~ 80 pc) The best target for studying GMCs and star formation within a whole galaxy Moderately face-on GMCs are distributed throughout the disk and are in relation to other components (e.g. star-forming regions, arms,…) (Arimoto et al.) Many star-forming regions over the whole disk

6. Data – Molecular gas : 12 CO(1-0) (45m) – Warm and dense molecular gas : 12 CO （ 3-2 ） （ ASTE ） : 13 CO(1-0) (45m) – Cold dust : 1.1mm （ ASTE ： AzTEC ） – Star-forming region : Ha （ SUBARU ） – Stars : B,V,R,I （ SUBARU ） – Atomic gas, IR …: （ Archived data ） Properties and evolution of GMCs

7. High resolution & wide field mapping w/ NRO 45m/ASTE 10m + OTF HPBW=16” @ CO(1-0) 25 beams! + OTF Array receivers “25BEARS” HPBW=22” @ CO(3-2) Tsys~150K! + OTF NRO 45m Atacama Submillimeter Telescope Experiment “CATS345” Highly uniform quality

8. 12 CO(1-0) map with NRO 45m 12 CO(1-0) with 45m Velocity field 1 kpc Many GMCs are identified Globally galactic rotation Tosaki et al. 2011

9. Color : 12 CO(3-2) with ASTE Grey & contour : 12 CO(1-0) with NRO 45m ΔT mb ~ 13 -20 mk 5×5 7.3×3.3 4.2×4.2 5.2×5.6 2.5×3 3.3×3.3 4.4×4 2.5×2.5 Total ~ 140 arcmin 2 Wide range of CO(3-2)/CO(1-0) Miura et al. 2012

10. 1.1 mm map Komugi et al. 2011

11. 1.1 Formation of molecular clouds 1.2 Relation between molecular gas and star formation 1.3 Evolution of Giant Molecular Clouds 1.4 Radial gradient of dust temperature

12. 1.1 Formation of molecular clouds – Molecular gas is formed more efficiently in inner region than outer region （ Tosaki et al. 2011 ） CO+HI CO+SFR

13. Correlation between gas surface density and f mol Two distinct sequences on the Σ gas – f mol Σgas fmol

14. Molecular gas fraction; f mol Function of 1.metallicity Z 2.radiation field U 3.gas pressure (or gas volume density n) (Elmegreen 1993) high Z/high n ⇒ efficient H2 formation high U ⇒ efficient H2 destruction

15. Vilchez et al. 1988 Sharp increase of metallicity in the central region from ~2kpc Model calculations are consistent with the observed results quantitatively 2 kpc

16. 1.2 Relation between molecular gas and star formation Kennicutt-Schmidt law global correlation between surface density of gas and star formation rate To what scale is the Kennicutt-Schmidt law valid? (Kennicutt et al. 2007) M51 0.5-2kpc scale

17. Check by changing spatial resolution from 1kpc to 80pc Becomes looser with higher spatial resolution ⇒ The Kennicutt-Schmidt law becomes invalid in GMC scale (~80pc) Difference of evolutionary stage of GMCs Σ(SFR) Hα,corr [M o yr -1 pc -2 ] (Onodera et al. 2010) Σ(H2)[M o pc -2 ] Resolution ~80pc ~250pc ~500pc ~1kpc 2σ Breakdown of the Kennicutt-Schmidt law at high resolution (~ 80 pc)

18. (Onodera et al. 2012 PASJ in press) SFR vs. CO(3-2) intensitySFR vs. CO(1-0) intensity Correlation between CO(3-2) and SFR => CO(3-2) traces denser and warmer gas

19. 1.3 Evolution of Giant Molecular Clouds – Variation of star-forming activity in molecular clouds （ Miura et al. 2012 ） Type C: With HII regions With young stellar groups (< 10 Myr) 71 GMCs Ha, 24um => HII regions Stellar groups Optical data => age of stars CO(3-2)/CO(1-0) CO(3-2) + young stars CO(1-0) + young stars Ha + young stars

20. Classification of GMCs: 4 types of GMCs Type A: No HII regions No young stellar groups 1 % Type B: With HII regions No young stellar groups 20 % Type C: With HII regions With young stellar groups (< 10 Myr) 45 % Type D: With HII regions With old stellar groups (10-30 Myr) 34 %

21. CO(3-2)/CO(1-0) => fraction of warm and dense gas GMCs with high SFR have higher CO(3-2)/CO(1-0) ratio => higher dense and warm gas fraction (Consistent with the correltion between CO(3-2) and SFR) Higher mass GMCs have higher CO(3-2)/CO(1-0) ratio (for GMCs with low SFR) => higher dense gas fraction Red > 5x10 -9 Mo yr -1 pc -2 Blue < 5x10 -9 Mo yr -1 pc -2 1.3 Evolution of Giant Molecular Clouds – Relation between properties of molecular clouds (evolutionary stage, mass) and dense gas fraction （ Onodera et al. 2012 ） Muraoka+ 2007

22. M33 AzTEC / ASTE ・ D= 0.84 Mpc, opt. size = 70’ x 40’ ・ obsered 2007-08, 30 hours on source  avg. τ 220GHz = 0.06 ・ 30’ x 30’ x 2 field, 28” = 120pc res.  most of SF disk ・ 1σ = 4-5 mJy/b = ~ 600 M o dust ・ 1100 um concentrated along spiral arms, SF regions. Good spatial correlation w/ HI overdensity regions ・ can be used for : Dust physics (w/ AKARI, Spitzer, Herschel) GMC evolution, SF studies (w/ CO, HI) star cluster / galaxy evolution (w/ Subaru) 1kpc Komugi et al. 2011 Cold dust temperature map from 1.1mm and Spitzer data Smooth gradient from G.C> to outer R 1.4 Radial gradient of dust temperature

23. 2. Preliminary results of ALMA cycle 0 observations of M83 (PI: A. Hirota) Mapping of M83 in 12 CO(1-0) HPBW=2.3”~50pc GMC can be resolved Best target for the comparison of GMC properties in spiral arms, bar, and central region => Influence on the GMC properties and their star forming activity Hubble 45m+NMA 200pcX100pc

27. ALMA Cycle 1 observations (PI: A. Hirota)

28. 3 ． CO Galactic Plane Survey with the NRO 45-m telescope OTF mapping of the Galactic plane and the outer disk in 12 CO(1-0), 13 (1-0), C 18 O(1-0) (simultaneously) with FOREST Mapping area – l ： 10° ～ 50° b ： ±1° （ 80 deg 2 ) Spiral arms （ Perseus, Sagittarius. Scutum-Centarus arms ）, bar sturcture, molecular gas ring – l ： 198° ～ 236° b ： ±1° Comparison between inner and outer regions (GemOB1, MonOB1, Maddalena cloud, CMa OB1 etc) Closer than the inner region => Noise level ~ 3 times higher than the inner region=> Observing time : ~1/9 FOREST 2X2 beam X 2 Pols X 2SB

29. NASA/R. Hurt

30. Advantages of NRO survey – High angular resolution  Can resolve clumps in the main Galactic structures (arm, bar, inner disk, outer disk) – Multi-line observation (simultaneously)  Structure of molecular clouds : Diffuse molecular gas – dense gas – Collaboration with VERA  measurements of the distance with VERA GRS NRO survey Nakanishi et al. 2006

31. Members Kagoshima univ. Handa, T., Nakanishi, H., Omodaka, T., Tanaka, A. （ M2 ）, Matsuo, T. （ M2 ）, Kamezaki(D1), Yoshida(M1), Osaka prefecture univ. Onishi, T., Nishimura (D2), Tokuda (M2) Joetsu education univ. Tosaki, T., Odaka(M1) Meisei univ. Onodera, S., Sofue, Y., Tsuda, Y. （ M2 ）, Ozawa, T. （ M2 ） ISAS Tsuboi, M. NRO Kuno, N., Umemoto, T., Hirota, A. （ PD ）, Matsui K. (PD) Chili observatory Higuchi, A. （ PD ） Mizusawa VLBI observatory Honma, M. et al. JCMT: CO(3-2) Mini-TAO: Paα

32. Summary M33 – Molecular gas is formed more efficiently in the inner region than outer region – The Kennicutt-Schmidt law becomes invalid in GMC scale (~80pc) for CO(1-0), but it is still valid for CO(3-2) – Life time of GMCs is estimated to be 20-40 Myr – Correlations between star forming activity and CO(3-2)/CO(1-0) ratio of GMCs GMC mass and CO(3-2)/CO(1-0) ratio – The cold dust temperature gradually decreases with radius M83 – Excellent data of the ALMA cycle 0 – Larger area will be mapped by ALMA cycle 1 observations CO Galactic Plane Survey with the NRO 45-m – GMC evolution and dense clump formation