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FUGIN: CO Observations Toward the Giant Molecular Cloud Complex W43: Dense Gas and Mini-Starbursts at the Tangential Direction of the Scutum Arm 0

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FUGIN: CO Observations Toward the Giant Molecular Cloud Complex W43: Dense Gas and Mini-Starbursts at the Tangential Direction of the Scutum Arm 0 Publications of the Astronomical Society of Japan (2017), Vol. 00, No. 0 7 Fig. 3. Integrated intensity maps of (a) 12CO, (b) 13CO, and (c) C18O J 1–0 in region A (l 12 to 22 , b 1 to 1 ). The integrated velocity range is = = ◦ ◦ = − ◦ ◦ 50 km s 1 < V < 200 km s 1.Panel(d)showstheSpitzerGLIMPSEimage(blue,3.6µm; green, 5.4 µm; red, 8.0 µm) in the same region. (Color − − LSR − online) 風神FUGIN FOREST Unbiased Galactic plane Imaging survey with Nobeyama 45-m telescope Optical image: Axel Mellinger 1 2019/03/05 Star formation with ALMA FUGIN: CO observations toward the Giant molecular cloud complex W43: Dense gas and mini-starbursts at the tangential direction of the Scutum Arm 0 Mikito Kohno (Nagoya university D2) K. Tachihara, S. Fujita, A. Ohama, A. Nishimura, M. Hanaoka, Y. Fukui (Nagoya), K. Torii, T. Umemoto, T. Minamidani, M. Matsuo (NRO), N. Kuno, M. Kuriki (Tsukuba), K. Tokuda (NAOJ/Osaka Pref), R. Kiridoshi, T. Onishi (Osaka Pref), Y. Tsuda (Meisei), and FUGIN team 1 NRO45m/FOREST (Red: 12CO J=1–0, Green: 13CO J=1–0, C18O J=1–0) NAOJ ‒1 1 0 12 13 18 Fig. 4. Three-color peak Tmb intensity image of region A: CO (red), CO (green), and C O (blue). (Color online) Spitzer/GLIMPSE+MIPSGAL (Red: 24μm, Green: 8μm, Blue:5.8μm) NASA/JPL-Caltech ‒1 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 three CO lines, and it is possible to investigate the global intense. The red clouds, which are very bright in 12CO but physical conditions of Galactic GMCs in a way similar to very weak in 13CO and C18O, indicate low optical depth Barnes et al. (2015). In figure 4,denseandwarmregions and high temperature regions. On the other hand, green are shown in white, where all 12CO, 13CO, and C18O are and blue clouds, where 13CO/12CO or C18O/12CO is high, Dense gas and6 high-mass star formationPublications ofin the Astronomicalthe GMC Society of Japan (2018), Vol. 00, No. 0 NGC 6334-6357 (Fukui+18) K km/s 1987IAUS..115....1L 12 Image (Spitzer): (a) HPBW grid 10 pc CO J=2-1 0 180 360 Red: 24 um 1.2 Vlsr: -30.0 - 4.0 km/s Green : 8 um Contour levels : min 25 K km/s, Step 25 K km/s 1.0 Blue : 3.6 um 0.8 0.6 0.4 Galactic Latitude [degree] (b) Contour levels : min 0.2 K degree, Step 0.4 K degree GMC GMC evolution GMC High-mass star 0 -10 Dense gas Vlsr [km/s] Vlsr 100 pc Lada 1987 -20 • What is the origin of the dense gas in the GMC ? Resolution B: 0.45 - 0.97 deg. • How do high-mass stars formed in the GMC ? 2 353 352 351 K degree Galactic Longitude [degree] 0.0 3.4 6.8 Fig. 4. (a) Integrated intensity map of 12CO J 2–1 obtained with NANTEN2. Purple and black crosses indicate infrared sources (PT08)andOB-type = stars (PT08, Fang et al. 2012), respectively. The final beam sizes after convolution and grid spacing are 90′′ and 30′′,respectively.Theintegrated 1 1 1 velocity range is from 30 to 4 km s− .The1σ noise level is 1.8 K km s− for the velocity interval of 34 km s− .Thelowestcontourandcontour −1 ∼ 12 intervals are 25 K km s− . (b) Galactic longitude–velocity diagram of CO J 2–1. The integrated latitude range is from 0.◦45 to 0.◦97. The velocity 1 = resolution is smoothed to 0.5 km s .The1σ noise level is 0.07 K degree for the latitude interval of 0.◦54. The lowest contour and contour intervals − ∼ are 0.2 K degree and 0.4 K degree, respectively. the main component and the blueshifted component in the 3.2 NGC 6334 following three regions: l 351.◦0– 351.◦5 (NGC 6334), 12 = Figure 6 shows a CO J 2–1 distribution of the main l 351.◦8–352.◦0 (MC351.9 0.7), and l 352.◦7–353.◦3 = = + = component of the NGC 6334 molecular cloud integrated (NGC 6357). 1 1 between 12 km s− and 2 km s− .Figure7 shows the 12 − Figure 5 shows the CO intensity line ratio of the 12CO distribution for the blueshifted component integrated J 2–1 emission to the J 1–0 emission in the l–b and 1 1 between 20 km s− and 12 km s− .Figure8 shows an = = − − velocity–l diagrams. We convolved the beam size of the overlay of the two components, which indicates a good 12 CO (J 2–1) to 180′′, which is the final beam size of the correspondence between the two velocity components. 12 = CO (J 1–0) data. The clipping levels of figures 5a and 5b 13 = Figure 9a shows the CO J 3–2 distribution of 1 = are 9σ (25 K km s− ) and 3σ (0.3 K degree), respectively. NGC 6334. We identified five 13CO clumps towards the far- The ratio is enhanced to be more than 0.8 in the regions of infrared sub-regions except for II, as listed in table 2.The GM 24, NGC 6334, and NGC 6357 in the main compo- clump boundary is defined at a 75% level of the peak inte- nent. We also note the bridge features toward NGC 6344 grated intensity. We derived the physical parameters using and NGC 6357 show enhancement of the ratio at 8– the 13CO J 3–2 emission (Buckle et al. 2010) under an 1 = 10 km s− . These high ratios suggest that the gas is in a assumption of local thermal equilibrium (LTE). Figure 9b high-excitation state due to heating by the high-mass stars. shows the radio continuum distribution, which traces the Downloaded from https://academic.oup.com/pasj/advance-article-abstract/doi/10.1093/pasj/psy017/4955196 by guest on 31 March 2018 steep intensity gradient in the 12CO emissions, while G012.820-00.238 is surrounded by molecular gas, especially in the 13CO and C18O emissions. W33 Main is sandwiched by these two H II re- 1 gions. The 45 km s− cloud has diffuse CO emission extended over the present region. The compact emissions at W33 Main and W33 A correspond to the wing features of the outflows (see Section 1 1 3.6 for details), and are thus not related to the 45 km s− cloud. Molecular gas in the 58 km s− cloud is separated into the northern and southern components relative to W33 and the central part corresponding to W33 is weak in the CO emission. There are several clumpy structures embedded at the northern rim of the southern component, which are clearly seen in the 12CO emissions, and these clumps show spatial correlations with radio continuum emissions from the H II regions G012.745- 00.153 and G012.692-00.251 as well as W33 B. In the C18O map in Figure 3(i) and Figure 4(d), W33 B is associated with the strong CO peak. There are several other clumpy molecular structures 1 at the interspace between the northern and southern components of the 58 km s− cloud, forming an arc-like molecular structure which looks surrounding W33. The size of arc-like structure is roughly estimated to be 7 pc. On the other hand, clear associations of molecular clumps with W33 A1 and ∼ W43 (Westerhout 43)W33 Main1 are not recognized. We derived the column densities and masses of the three velocity clouds using the 12CO in- Spitzer, blue: 3.6 μm, green: 8.0 μm, red: 24 μm tegrated intensity maps shown in Figures 3(a)-(c), where we defied the individual clouds by drawing • Parallactic distance 1 (a) contours at 5σ noise levels in the integrated intensity of 8 K km s− for the velocity interval of 10 5.51 kpc 20 1 1 2 km s(Zhang− . Byet al. assuming 2015) a X(CO) factor of 2 10 (K km s− )− cm− (Strong et al. 1988), we esti- × 1 1 1 22 mated• GMC the meancomplex column densities of the 35 km s− , 45 km s− , and 58 km s− clouds as 1.7 10 × 2 22 2 21 2 cm− ,–1.Size7 10: 100cm− pcand 6.2 10 cm− , respectively, with the total molecular masses derived × × W43 Main W43 South as 1.1– 10Mass5M : ,7.11.0101065M , and 3.8 104M . The uncertainty of mass estimation using X-factor × (Nguyen⊙ Luong+2011)× ⊙ × ⊙ is about 30 % (Bolatto et al. 2013). Lin et al. (2016) derived the mean column densities as • Three± high-mass star 22 2 2.5 10 cm− using the infrared dust emission data obtained by Herschel, which is consistent with ×forming regions G30.5 our estimate.– W43 Main – G30.5 N 3.2 C–18OW43 molecular South clump properties 50pc We define C18O molecular clumps using the following procedures in order to investigate the physical 1 1 properties of dense molecular gas belonging to the 35 km s− and 58 km s− clouds corresponding to (b) W43 Main (c) G30.5 (d) W43 South the dust clumps. IRAS 18445-0222 G030.213-00.156 (Bally+2010)1. Search for a peak integrated intensity toward the six dust clumps. Galactic mini-star burst region 3 2. Define a clump boundary as the half level of its peak integrated intensity. IRAS 18447-0229 3. If the area enclosed by the boundary have multiple peaks, define the boundary as a contour of the G030.404-00.238 10 IRAS 18456-0223 10pc 10pc 10pc Publications of the Astronomical Society of Japan, (2014), Vol.
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