Gas of Planck Cold Dust Clumps Yuefang Wu Astronomy Department,Peking University Team: Tie Liu, Fanyi Meng, Huawei Zahng, Jinghua Yuan Ping Chen, Runjie Hu, Taiwei Zhang Collaborators: Di Li, Sheng Li Qin, Bingang Ju, Karl Menten Christian Henkel , Arnaud Belloche, Xin Guan

Outline 1. Planck early results and follow-up studies 2. Our observations: CO survey Dense molecular line observation 3. General properties 4. Mapping results 5. Future work

1. Early results of Planck Satellite ECC Sources 10783 ~14 K Mass: 1-10^5M⊙ 915 most reliable Follow up studies Various equipment: Herschel PMO 13.7m 100, 160 Molecular lines 250, 350μm Still continuum Key for Dynamics

2. Our observations CO Surveys 2011-12 J=1-0 of CO, 13CO，C18O: PMO, 13.7m, 56” Receiver： Nine beam SIS array Velocity resolution: 12CO: 0.16 km/s 13CO, C18O: 0.17 km/s rms: 12CO, 0.2 K : 13CO, C18O : 0.1 K Single point: on/off Mapping： OTF More than 600 CO cores were obtained 2012-14 Dense molecular lines: --under progress J=1-0 of HCO+, HCN, N2H+ PMO 2013-14 IRAM map, 3’x3’, Apr. 30-May 5, 24 sources were mapped Several cores were observed with 2-1 of CO, 13CO，C18O at CSO Publication: Wu et al +12, ApJ 756, 123; Liu, Wu Meng 2012, ApJS 202, 4; Meng, Wu, Liu 2013, ApJS 209, 7; Liu, Wu, Zhang 2013, ApJL, 775,L2

3. General properties: CO results All were observed, but 39 of the cores have reference position problem All were detected with 12CO and 13CO, 68% for C18O Double and more components were identified, 108 additional components were obtained for 12CO J=1-0 10% 13CO J=1-0 emission <3σ 50% C18O J=1-0 emission <3σ :

1). Line center velocity; distance Basic parameter Histogram: Normal distribution V12-V13; V13-V18 Correlation: V12 vs. V13 V13 vs. V18 100% Velocity difference of molecular lines is very common In the 6 NH3 cores of IRDC G084.81−01.09: Vlsr(CO)-Vlsr(13CO) (Zhang et al. 2011) All are > 1 km/s

•D: range 0.1 – 22 kpc • 82% < 2 kpc • 51%: 0.5 –1.5 kpc The agreement was revealed for the first time Initial conditions of star formation - less dynamic layer of the molecular regions System velocity: 13CO line more optical thin that CO, more common than C18O V13 center velocity- system velocity A basic application kinematic D D from IRDCs (Simon et al. 2006) most are on Galactic plane •D: range 0.1 – 22 kpc • 82% < 2 kpc • 51%: 0.5 –1.5 kpc

2). Physical parameters and line profile Excitation temperature: Derived from T12 Assuming 12CO optical thick If the system is LTE, then kinematic temperature Tk obtained Range: 3.9 –27 K wider than that of Td: 7- 17 K Higher part: 12 with Tk > 17 K, all are located in Orion and Tauri Lower part: additional components dust emission are not resolved yet Property of distribution: deviated from lognormal distribution is small

Line widths: Observed FWHM: Most of the cores with narrow lines A criterion: 1.5 km/s for High-mass and Low-mass cores (Myers et al. 2083; Wu et al. 2003; Wang et al. 2009) H: 162; the remain belong to L. Thermal and non-thermal velocity dispersion: as well as σ3D were investigated Property of the distribution:

Column density NH2 : NH2 and the related optical depth tau13 derived from T13 with radiation transfer equation assuming 13CO line optical thin NH2 spans from 1020 to 4.5x1022 cm-3 , much larger than that of the nearby cores (Myers et al. 1983) Distribution: K-S test: Both are lognomal distribution + power larw tail

Line profiles: 15 cores: center dip, absorption at the line center, rather symmetric Blue asymmetric, 58 Red asymmetric ,40 Blue profile, 15 (Nb) --2% Red profile, 5 (Nr) -- 0.8% small blue excess: E= (Nb-Nr)/Nt =0.01 (Nt=782) very small IRAM observation of HMPs and UCHII: 0.17 and 0.58 respectively (Wu et al. 2007) But blue profiles > red profiles, implying more cores are going to collapse than the protostellar objects driving mass outward

Velocity dispersions: With R: All, highest at 5 kpc dynamic process is most violent at 5 kpc ring from 6 kpc, linearly increase turbulence becomes more strong in the out part of the Galaxy With Z: All decrease with Z from the disk to Z=475-525 pc High again at ~680 pc minor peak related with Orion, Tauri Revealed for the first time

High latitude: 41 higher than 250 the highest 710 , previous 440 5: belong to group H NH2: 3x1021 cm-2 , average, σNT smaller among the 12 regions regions but larger than that in Oph, Oph-Sgr, Tex: intermediate 3 BA: G004.54+36.74 Z: 930 pc G131.35-45.73 1200 pc G151.88-34.18 670 pc 3 RA: G006.64+36.74 2710 pc G210.67-36.77 150 pc G161.43-35.59 was mapped Surveys: 16o≤b ≤ 44o,117o≤l ≤ 160o 13% CO detected(Heithausen ea 1993) -30o—(-43o) : 110 clouds not dense enough to form stars (Yamamoto ea 2003  Planck cores are more closer to SF status

3). CO abundance and depletion Liu, Wu, Zhang 2013 correlates with Td,L/M anti-correlates with β Depletion: Correlates with β anti-correlates with

4). Evolutional states of the cores Comparison for cumulative of FWHM of 13CO lines and NH2 of 5 different star formation samples FWHM: Methanol maser source have the largest FWHM Planck cores the smallest NH2: Column density: Planck cores the smallest too

4. Mapping results Search CO cores: CO mapping: Data were divided into Regions according to Dame et al. (1987) All the regions: ~630 cores Example: Orion Liu, Wu Zhang, 2012 Grey:Hª Red:CO (Dame ) Blue: 100μm Green: Planck clumps

51 clumps 82 cores

Example: Taurus: Meng, Wu, Liu 2013 Dots: Planck clumps Colour: Vlsr

Taurus: Meng, Wu, Liu, 2013 71 Clumps 38 cores

1). Dense cores: Single point observed with 1-0 of HCO+ 1). Dense cores: Single point observed with 1-0 of HCO+. HCN 170 were detected with HCO+ and 120, HCN So far 24 were mapped with (1-0) of HCO+, HCN and N2H+ using IRAM Some of the cores have been observed with CSO too

HCO+ (1-0) and HCN (1-0)

Mapping with IRAM and CSO

13CO 2-1 13CO 1-0 counters 12CO 1-0 Grey scale C18O 2-1 Black filled star: YSO 13CO 2-1

Checked with infrared data: Wise W1-W4 wavelength bands 104/170 were starless candidates Examples: 3.4, 4.6 and 12 μm, 22 μm -- Without protostellar mid-infrared counterparts

2). Diffuse clouds: Most with stellar sources; star less N≤ 1020 cm-2

Evolution routing: ISMmolecular cloudsISM Four-steps: Starless diffuse Diffuse with sources (ISM to molecular cloud) (Masers, YSOs, …) FAST HI emission FAST HI absorption Starless core Cores with sources (Cores form within cloud) (star-forming phase)

5. Future work: Surveys with CO 1-0 and 3 mm lines: HI observation: Complete the 1-0 of CO, 13CO and C18O with PMO I, I, III, Cep Dense molecular lines: N2H+, D2H+ (1-0) HC3N, HC5N, SiO NH3 Southern hemisphere, MOPRA, in preparing HI observation: It is on going by Prof. Li Prepare for FAST High resolution continuum observation JCMT SCUBA2 : Legacy project organized by Tie Liu High frequency line observation ESO project organized by Ke Wang was approved

Thank You!