The “TOP” “SCOPE” - Interstellar Medium

The “TOP” “SCOPE”:
Follow-up surveys toward Planck Galactic cold clumps with ground-based radio
telescopes
Tie Liu (KASI fellow)
Korea Astronomy and Space Science Institute
[email protected]
https://tikitest.asiaa.sinica.edu.tw/tiki/tiki-index.php
16. 06. 03.
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Science topics 1. How dense cores form and how star forma8on varies as a func8on of environment? 2. the universality of filaments in the cold ISM and their roles in genera8ng dense cores 3. the existence of a density threshold for dense core forma8on 4. How dust proper8es change in different environments and, how dust proper8es affect the chemical evolu8on of dense cores? 5. a comparison between some of the isolated Planck/JCMT cores and the clustered cores they have already found in the JCMT Gould Belt Survey 6. Bright extragalac8c sources 7. Core-­‐YSO associa8on 8. Magne8c Fields in ISM 9. HI-­‐H2 Transi8on and cloud evolu8on 10. Collapsing and Oscillatory starless cores 11. Gas-­‐grain chemistry, Dust grain proper8es and density profiles 12. Study of the cores with lower masses (e.g. brown dwarfs) 13. Search for the first hydrosta8c core candidates 14. Core forma8on in Lamda Orion complex 15. Distance es8mates 16. triggered star forma8on (HII regions, cloud-­‐cloud collision) 17. ….. 16. 06. 03.
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The team Tie Liu (KASI, KR) 16. 06. 03.
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53 New members since open enrollment
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Outline
1. Introduction
2. Joint surveys and follow-up observations
3. Preliminary results
4. Summary
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What are Planck galactic cold clumps (PGCCs)?
Planck is a third generation space based
cosmic microwave background
experiment, operating at nine frequencies
between 30 and 857 GHz
Planck Catalogue of Galac8c Cold Clumps (PGCC), 13188 clumps
The early cold core (ECC) sample: 915
sample Td<14 K, SNR>15
“We believe that the PGCC catalogue, covering the whole sky, hence probing wildly different environments, represents a real goldmine for inves>ga>ons of the early phases of star forma>on. These include, but are not limited to: i) studies of the evolu>on from molecular clouds to cores and the influence of the local condi>ons; ii) analysis of the extreme cold sources, such as the most massive clumps or those located at rela>vely high la>tude; iii) characteriza>on of the dust emission law in dense regions and he 16. 0t6. 03.role of the environment.” Planck collaborators et al. (2015) 6
2. Joint surveys and follow-up observations
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Galac8c distribu8on PGCCs All-­‐sky distribu8on of the 13188 PGCC sources (black dots) and the 2000 selected PGCC sources (open dots) overlaid on the 857 GHz Planck map (credit: M. Juvela). 16. 06. 03.
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PGCC parameter distributions
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(credit: M. Juvela) 9
TOP: TRAO Observations of Planck cold clumps
•  Targets: 2000 PGCCs
•  Tracers: 12CO (1-0) and 13CO (1-0)
Taeduk Radio Astronomy Observatory (TRAO) •  Telescope: 13.7 m TRAO telescope (same as FCRAO, PMO)
•  Receiver: SEQUOIA is a cryogenic focal plane array designed for the 85-­‐115.6 GHz range. 32 pixels are arranged in a dual-­‐polarized 4x4 array. The noise temperature ranges from 50-­‐80K over most of the band. Tsys: ~250 K for 13CO (1-0) , ~500 K for 12CO (1-0)
Observations
•  Single pointing Obs:
•  3 minutes (on+off+cal) per source
•  Rms: <0.15 K @ 0.3 km/s for 13CO (1-0), <0.3 K @0.3 km/s for 12CO
•  Otf Mapping Obs：
•  ~42 minutes per source for a 15arcmin*15arcmin map
•  Rms: ~0.25 K @ 0.3 km/s for 13CO (1-0), <0.5 K @0.3 km/s for 12CO
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Status of “TOP” Un8l end of May, ~150 fields have been mapped in 12CO/13CO (1-­‐0). The mapping sizes range from 6arcmin*6arcmin to 30arcmin*30arcmin. Nearly all the Herschel fields observed at JCMT in 2016A have been mapped by “TOP”. Below, I show an example of 13CO (1-­‐0) map of a high-­‐la8tude cloud G159.21-­‐34.28. Interes8ngly, the dense regions show very different veloci8es from the surroundings. 16. 06. 03.
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SMT PMO 13.7 m SEQUOIA 16. 06. 03.
TRAO 13.7 m 12
SCOPE With a diameter of 15m the James Clerk
Maxwell Telescope (JCMT) operated by
EAO is the largest astronomical telescope in
the world designed specifically to operate in
the submillimeter wavelength region of the
spectrum
16. 06. 0. 3. SCUBA-2 (Submillimetre Common-User
Bolometer Array 2) is a 10,000 pixel bolometer
camera operating simultaneously at 450 and 850
micron. The camera has in total eight TES arrays, four at each wavelength band. With each array having 32×40 = 1280 bolometers there are in 13
total 5120 bolometers per wavelength. 16. 06. 03.
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constant velocity (CV) Daisy mode 15 minutes per source
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•  6 mJy/beam within central 3 arcmin
•  10-30 mJy/beam in the map out to 12 arcmin
TRACK panern 16. 06. 03.
Exposure 8me map 15
Why 850 micron? •  1. Could be done under normal/bad weather condi8ons (grade 3 &4) •  2. The SCUBA-­‐2 850 micron data are essen8al for constraining SED fits and determining dust emissivity (beta) (beta map; Hersche+850 micron) (beta map; Hershel only) Perseus B1 clump: Sadavoy et al. 2013 16. 06. 03.
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When compared with previous con8nuum surveys, “SCOPE” is the first “all-­‐sky” high sensi8vity and high angular resolu8on mm/sub-­‐mm con8nuum survey. 16. 06. 03.
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Status of “SCOPE” 150 observed in pilot phase, 359 observed in “SCOPE” PMO selected sources: 37/60 Herschel selected sources: 68/78 Lamda Orion region: 11/49 HINSA: 12/31 180 PGCCs in Galac8c, ~100 observed, very high detec8on rate (>80%) •  ~530 MSBs for new sources submined • 
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•  Data release: We are s8ll improving the pipeline. The standard data reduc8on pipeline is fine for compact sources, but we lost extended structures. Data will be released when the pipeline is fixed. 16. 06. 03.
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TianMa 65-­‐m Effelsberg 100-­‐m 16. 06. 03.
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Arecibo 300-­‐m NRO 45-­‐m 16. 06. 03.
FAST 500-­‐m SMA 20
Summary of joint surveys
1. PMO/TRAO 13.7-­‐m telescope survey in the J=1-­‐0 transi8ons of CO isotopologues TRAO Observa8ons of Planck cold clumps (TOP): 400hrs/yr for 3 years Goals: large scale structure & kinema8cs 2. SMT 10-­‐m telescope survey in the J=2-­‐1 transi8ons of CO isotoplogues (PI: Ke Wang, 600 hrs/3yrs). Goals: CO excita8on, column density and deple8on, kinema8cs 3. SCOPE: SCUBA-­‐2 Con8nuum Observa8ons of Pre-­‐protostellar Evolu8on (300 hrs for first phase) Goals: dense cores and filaments 4. KVN 21-­‐m telescope survey in dense gas tracers (e.g. HCN, HCO+, N2H+) (PI: Kee-­‐Tae Kim, pilot survey done, large proposal to be submiUed in July) Goals: chemistry & kinema8cs of dense cores 5. NH3 follow-­‐up survey with Effelsberg 100-­‐m and TianMa 65-­‐m (PI: Yuefang Wu, ~30 hrs at 100-­‐m. Proposal to TianMa 65-­‐m to be submiUed by the end of this year) Goals: kine8c temperature & turbulence 6. HI survey with Arecibo 300-­‐m and future FAST 500-­‐m telescopes (PI : Di Li) Goals: HI abundance and chemical evolu8on of molecular clouds 7. Follow-­‐up observa8ons with NRO 45-­‐m (PI: Ken Tatematsu, ~150 hrs in 2015B) Goals: Chemistry 8. Follow-­‐up observa8ons with the SMA (PI: Sheng-­‐Yuan, Harju, Qizhou) Goals: Fragmenta8on and small scale structures/kinema8cs 9. ALMA !!! (three proposals submiited in cycle 4) 16. 06. 03.
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3. Preliminary results
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HINSA (HI Narrow Self-­‐Absorp8on) detections with Arecibo 300-m (Di Li)
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HI 12CO x 2 13CO x 2 C18O x 2 23
HINSA detections with Arecibo 300-m (Di Li)
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13CO x 2 HI 12CO x 2 C18O x 2 24
HINSA sources in “SCOPE” 16. 06. 03.
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High-Latitude clouds (|b|>30 deg.)
Dense gas clumps revealed in PMO/TRAO survey. But most of them have no SCUBA-­‐2 detec8ons. Density too low to form cores? 16. 06. 03.
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Galac8c Plane PGCCs The dense cores are more clustered, most in filaments, when compared with PGCCs above the plane. 16. 06. 03.
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filament-filament collision? (Jorma’s talk yesterday)
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PGCCs in Orion Lamda Orionis 16. 06. 03.
Orion A+B (Hα, IRAS 100 micron, Planck 353GHz +: PGCCs without SCUBA-­‐2 detec8ons 29
White s
tars: P
GCCs w
ith S
CUBA-­‐2 d
etec8ons) (Hee-­‐weon Yi, in prepara8on) SCUBA-­‐2 cores in Orion Planck SCUBA-­‐2 SCUBA-­‐2 Protostellar core frac8on: Lamda Orionis (9/15), Orion A (30/73) , Orion B (9/28) Lamda Orionis cores have higher temperature, lower beta, lower mass and lower column density than Orion A+B cores. 16. 06. 03.
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Suppressed core forma8on in Lamda Orionis due to stellar feedback? 16. 06. 03.
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brown-­‐dwarf and very low-­‐mass star forma8on (Liu+2016ApJS 222, 7L) 850 micron MIPS 70 micron 1.3 mm MIPS 24 micron Green Contours: Spitzer/MIPS 70 μm Blue contours: SMA 1.3 mm 16. 06. 03.
Extremely young Class 0: G192N: M=0.43 Msun (JCMT); M=0.38 Msun (SMA); Lint=~0.2 Lsun Proto-­‐brown dwarf: G192S: M=0.23 Msun (JCMT); M=0.02 Msun (SMA); Lint=~0.08 Lsun 32
brown-­‐dwarf and very low-­‐mass star forma8on (Liu+2016ApJS 222, 7L) MIPS 70 micron Green Contours: Spitzer/MIPS 70 μm Blue contours: SMA 1.3 mm MIPS 24 micron G192N very young Class 0 protostar G192S proto brown dwarf candidate e16. xtremely low accre8on rate 2.8 10−8 M☉yr−1 indicates G192S likely forms a brown dwarf 06. 03.
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brown-­‐dwarf and very low-­‐mass star forma8on (Liu+2016ApJS 222, 7L) 1.3 mm con8nuum in color image and black contours; CO ouwlows in red and blue contours 16. 06. 03.
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initial fragmentation of filaments and core evolution
G207N 850 micron Color: CO abundance Contours: H2 column density from Herschel The northern clump show larger CO deple8on and smaller [HCO+/N2H+] ra8o than the southern clump, indica8ng the northern clump is more evolved. 16. 06. 03.
(HCO+: balck contours; 850 micron in color) 35
initial fragmentation of filaments and core evolution
•  Thermal jeans fragmenta8on in G207S? 16. 06. 03.
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Korean VLBI Netvork (KVN) observa8ons •  52 dense cores in 20 fields observed •  Target lines: 22 GHz water maser, 44 GHz water maser, J=1-­‐0 of HCO+ and N2H+ as well as H2CO 2(1,2)-­‐1(1,1) •  TRMS < 0.1 K @ 0.2 km/s •  No detec8ons of masers •  High detec8on rate in H2CO 2(1,2)-­‐1(1,1) •  Evolu8on in N(N2H+)/N(HCO+)? 16. 06. 03.
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G162.4-­‐08.7 (DOBASHI 4225) by KVN SCUBA2, 850μm H2CO x 2 CH3OH N2H+ x 2 H2O HCO+ x 2 WISE W4, 22μm 16. 06. 03.
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G204.4-­‐11.3 SCUBA2, 850μm First hydrosta8c core (FHSC)? H2CO x 2 CH3OH N2H+ x 2 H2O HCO+ x 2 WISE W4, 22μm IRAS 850 micron in contours WISE 22 micron in color 16. 06. 03.
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NRO 45-m follow-up observations (Ken Tatematsu)
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We have observed 15 Planck cold clumps with NRO 45-m telescope, which have
precise positions (SCUBA2 etc) and are relatively close (C18O linewidth is <1.0
km/s).
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(1) 13 out of them, we made OTF with receiver TZ for N2H+, HC3N, two CCS
lines. The map size is usually 2'x2', but 3x3 or 4x4 for some of them. N2H+ was
detected for all sources, and we detected 81 GHz CCS from 10 out of 13. This
detection rate 77% is appreciably higher than 32% in 45 GHz CCS toward Orion A
GMC (Tatematsu+10), 0% in 45 GHz CCS toward IRDCs (Sakai+08), although
frequency and sensitivity are different. Suzuki+93 ' detection rate in CCS 45 GHz
toward nearby dark clouds is 27/49 (55%). Our detection rate is close to theirs, or
even more. Planck cold clumps should be as young as nearby dark clouds or even
younger.
(2) 9 out of 15 were observed with receiver T70 for DNC, HN13C, N2D+, c-C3H2 in
single-position mode. Usually, DNC, HN13C, c-C3H2 are easily detectable
except for G207.3N. Four out of nine were detected in N2D+ hyperfine!!!
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Note: c-C3H2 : cyclopropenylidene
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CCS-­‐N2H+ configura8on for prestellar core SCUBA2 850 μm con8nuum contours on WISE 22 μm image 16. 06. 03.
Gray image: SCUBA2 850 μm con8nuum Black contours: N2H+ (1-­‐0) Blue contours: CCS, CCS is depleted toward the core Red contours: HC3N (cyanoacetylene) (Tatematsu, K. in prep.) 41
Summary
•  The Planck telescope has provided us with an unprecedented sample of “all-­‐sky” pre-­‐stellar object candidates. Planck cold clumps correspond to the coldest por8on of the ISM where stars form, and can be used to characterize the earliest stages of star forma8on. In order to make significant progress in understanding the early evolu8on of molecular clouds and dense cores in a wide range of Galac8c environments, we are carrying out unbiased “all-­‐sky” surveys of 1000-­‐2000 Planck cold clumps in J=1-­‐0 of CO/13CO lines with TRAO 14-­‐m telescope and 850 µm con8nuum with the JCMT/SCUBA-­‐2. We are also ac8vely developing follow-­‐up surveys/observa8ons (SMT, KVN, FAST, NRO 45-­‐m, SMA) for these legacy surveys, which will allow us to deepen the inves8ga8on of the dense core or star forma8on in widely different environments at their earliest evolu8onary phases. Our survey will also provide a unique legacy database for such studies with other instruments, especially with ALMA. •  Our pilot observa8ons have proved that Planck cold clumps are really interes8ng for studies of ini8al condi8ons of star forma8on at their earliest evolu8onary stages in various environments. Our survey data could be used for various science topics related to star forma8on and cloud evolu8on. 16. 06. 03.
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