[CI] mapping of the super star cluster RCW38 (ASTE [CI] Demo - PowerPoint PPT Presentation

[CI] mapping of the super star cluster RCW38 (ASTE [CI] Demo Science Project) Natsuko Izumi (NAOJ) Yasuo Fukui, Kengo Tachihara, Shinji Fujita (Nagoya U), Kazofumi Torii, Takeshi Kamazaki, Hiroyuki Kaneko, Takeshi Nakazato George Kosugi, Jun Maekawa, Shigeru Takahashi, Akira Yoshiko, Daisuke Iono (NAOJ), Kanako Sugimoto (NRAO) and ASTE team

1. INTRODUCTION ❖ Target: Super Star Cluster RCW38 Spitzer (r: 8.0 um, g: 4.5 um, b: 3.6 um) VLT (r: 2.2 um, g: 1.65 um, b: 1.25 um) Wolk et al. 2006

1. INTRODUCTION ❖ Target: Super Star Cluster RCW38 • Distance : ~ 1.7 kpc VLT (r: 2.2 um, g: 1.65 um, b: 1.25 um) • Youngest super star cluster in the Milky Way ‣ ~ 0.1 Myr ‣ ~ 10,000 star (~ 20 O stars) • 2 IR peaks ‣ IRS1: ridge structure ‣ IRS2: O5.5 binary Wolk et al. 2006 e.g. Fukui et al. 2016

1. INTRODUCTION ❖ Triggered Star formation by Cloud-cloud collision • CO mapping observation with Mopra Fukui et al. 2016 12 CO(1-0) Ring Finger Ring Finger Bridge • Two molecular clouds ( Δ v ~ 12 km/s) ‣ Ring cloud: blue-shifted (v LSR = -8.3 - 9.1 km/s), N H2 > 10 23 cm -2 ‣ Finger cloud: red-shifted (v LSR = 9.1 - 17.5 km/s), N H2 ~ 10 22 cm -2 • Bridging feature between two clouds Haworth et al. 2015a,b

1. INTRODUCTION ❖ Triggered Star formation by Cloud-cloud collision • CO mapping observation with Mopra Fukui et al. 2016 12 CO(1-0) Ring Finger Ring Finger Bridge • Two molecular clouds ( Δ v ~ 12 km/s) ‣ Ring cloud: blue-shifted (v LSR = -8.3 - 9.1 km/s), N H2 > 10 23 cm -2 ‣ Finger cloud: red-shifted (v LSR = 9.1 - 17.5 km/s), N H2 ~ 10 22 cm -2 • Bridging feature between two clouds Haworth et al. 2015a,b

2. OBSERVATION ❖ [CI] mapping observation with Band8 receiver Spitzer (r: 8.0 um, g: 4.5 um, b: 3.6 um) Obs. date 2016/11/26 Receiver Band 8 Spectrometer MAC Mapping area Mode OTF mapping Frequency 492.1607 GHz IRS1 IRS2 Bandwidth 512 MHz Spectral resolution 1 MHz (~0.6 km/s) 8’ HPBW ~17’’ (~ 0.14pc) Mapping area 6’ × 8’ Total mapping time ~ 6 hrs 6’ Tsys 800 ~ 1400 K PWV ~0.5 Opacity (220 GHz) 0.02 ~ 0.07 RMS noise ~ 0.46 K (Tmb)

3. DATA REDUCTION ❖ Software • Data reduction with NOSTAR and CASA ‣ NOSTAR: Mainly used for OTF mapping data from NRO 45m and ASTE ‣ CASA: Mainly used for data from ALMA, VLA The raw data, final cube data, and detailed analysis procedures are already published on the ASTE web page https://sites.google.com/site/ asteobservation/home/reduction#TOC- DEMO-SCIENCE-DATA-REDUCTION- GUIDE

4. RESULT ❖ Ring-like structure Spitzer (r: 8.0 um, g: 4.5 um, b: 3.6 um) Mapping area IRS1 IRS2 IRS1 8’ IRS2 6’ 6’

4. RESULT ❖ Two velocity component [CI] Ring Finger Ring Finger • Similar structure to CO clouds Fukui et al. 2016 ‣ Ring cloud: blue-shifted (v LSR = -8.3 - 9.1 km/s) , N [CI] ~10 18 cm -2 ‣ Finger cloud: red-shifted (v LSR = 9.1 - 17.5 km/s) , N [CI] ~ 10 17 cm -2

5. DISCUSSION ❖ Relation between [CI] and 13 CO in RCW38 • Past studies reported that [CI] distribution is similar to 13 CO(1-0) distribution ‣ Orion (e.g. Ikeda et al. 2002, Shimajiri et al. 2013) ‣ Southern Milky Way (Oka et al. 2005) ‣ Carina nebula (e.g. Kramer et al. 2008) Ikeda et al. 2002

5. DISCUSSION ❖ Relation between [CI] and 13 CO in RCW38 [CI] Ring Finger Ring (ASTE) Finger 13 CO(1-0) (Mopra) Fukui et al. 2016

5. DISCUSSION ❖ Relation between [CI] and 13 CO in RCW38 [CI] (ASTE) [CI] distribution is very similar to 13 CO distribution !! 13 CO(1-0) (Mopra) Fukui et al. 2016

5. DISCUSSION ❖ [CI] / 13 CO ratio in RCW38 W [CI] (K km/s)/ W 13CO (K km/s) Contour: [CI] Ring Finger Ring Finger • [CI]/ 13 CO ratio in Finger cloud is higher than that in Ring cloud ‣ Ring cloud: ~ 1.5 ‣ Finger cloud: ~ 1.0 - 5.0

5. DISCUSSION ❖ [CI] / 13 CO ratio in RCW38 I [CI] (K) vs. I 13CO (K) I 13CO = I [CI] Ring: I 13CO = 0.64 I [CI] Orion: I 13CO = 0.62 I [CI] (Shimajiri et al. 2013) Finger: I 13CO = 0.49 I [CI]

5. DISCUSSION ❖ Relation between [CI] / CO and N H2 (Av) Finger: N CO = -1.3 × 10 -23 N [CI] + 0.3 Ring: N CO = -3.1 × 10 -27 N [CI] + 0.09 • N [CI] /N CO (~ [CI]/[CO]) is constant (~ 0.1) at A V ~ 10 - 100

5. DISCUSSION ❖ Relation between [CI] / CO and N H2 (Av) Finger: N CO = -1.3 × 10 -23 N [CI] + 0.3 Ring: N CO = -3.1 × 10 -27 N [CI] + 0.09 • N [CI] /N CO (~ [CI]/[CO]) is constant (~ 0.1) at A V ~ 10 - 100 Difficult to explain by Layered PDR model

5. DISCUSSION ❖ Relation between [CI] / CO and N H2 (Av) Finger: N CO = -1.3 × 10 -23 N [CI] + 0.3 Layered PDR model (CLOUDY): Rolling et al, 2007 UV from 05.5 star, n H2 = 10 4 cm -3 Ferland et al. 2003 Ring: N CO = -3.1 × 10 -27 N [CI] + 0.09 • N [CI] /N CO (~ [CI]/[CO]) is constant (~ 0.1) at A V ~ 10 - 100 Difficult to explain by Layered PDR model

5. DISCUSSION ❖ Relation between [CI] / CO and N H2 (Av) Finger: N CO = -1.3 × 10 -23 N [CI] + 0.3 PDR model (CLOUDY): Rolling et al, 2007 UV from 05.5 star, n H2 = 10 4 cm -3 Ferland et al. 2003 Ring: N CO = -3.1 × 10 -27 N [CI] + 0.09 Suggest clumpy PDR model?? We need follow-up observation.. • N [CI] /N CO (~ [CI]/[CO]) is constant (~ 0.1) at A V ~ 10 - 100 Difficult to explain by Layered PDR model

6. SUMMARY ❖ [CI] mapping toward the RCW38 • Detect two velocity component ‣ Ring cloud: blue-shifted (v LSR = -8.3 - 9.1 km/s) , N [CI] ~10 18 cm -2 ‣ Finger cloud: red-shifted (v LSR = 9.1 - 17.5 km/s) , N [CI] ~ 10 17 cm -2 • [CI] distribution is very similar to 13 CO distribution ‣ Same result as past studies (e.g. Orion, Carina nebula) • N [CI] /N CO (~ [CI]/[CO]) is constant (~ 0.1) at A V ~ 10 - 100 ‣ Difficult to explain by Layered PDR model → Suggest clumpy PDR model ?? We plan to follow up observation with ALMA !!