Star and Planet Formation: Science Driver for Submm/THz Telescope in Dome A

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1 Star and Planet Formation: Science Driver for Submm/THz Telescope in Dome A 张其洲 Harvard-Smithsonian Center for Astrophysics and CAS International Partner Group ( 国际合作团队 )

2 Why TeraHertz? Under-explored frequency window HST Spitzer/Herschel ALMA/SMA VLA Half radiation energy in FIR/THz

3 Herschel: Opens up new field for far IR/Tera Hertz Astronomy 3.5 m, L2 orbit PACS: 5x5 spatial x 16 spectral pixels, micron, R ~ SPIRE: micron, R ~ HIFI: Heterodyne spectroscopy, R up to 10 7, , micron Designed for 3 year lifetime!! Low spatial resolution (~20 at far IR)

4 Why THz Telescope in Dome A? Discovery Space Herschel Credit: Xianzhong Zheng Driest Site An under-explored window Sensitivity/Spatial resolution (x20 in collecting area, x4 in angular resolution than Herschel)

5 Why Single dish Telescope in ALMA Era: Superb Imaging Speed Dome A µm 350μm Single dish telescopes with large format Bolometer Array out perform ALMA in large field surveys Dome A 15m telescope has resolution approaching interferometer Interferometer Single Dish

6 Unprecedented Sensitivity to Star Forming Gas 15m 3 at 200μm Current Galactic Surveys ATLASGAL HiGAL BoloCAM Most Current Surveys ATLAGAL Deep SCUBA-2 DomeA 15m > x10 better sensitivity Detecting Jupiter to BD mass objects to distance of 1000pc

7 Resolution is important B:70 μm, G:170 μm, R:350 μm Herschel IRAS μm μm 1d W43 mini starburst

8 Unique Lines in Tera Hertz Window ALMA Herschel/HIFI Herschel/HIFI Credit: Paine, Marrone

9 PreHeat: Perceptible water vapor from Dome A best 25% weather at Mauna Kea Winter median at ALMA site CCAT site: Stairecabur Dome C Walker, private communication; Yang et al Jan. 5, 2009 URSI, Boulder, Colorado

10 Proposed Road Map for Dome A An FTS to be deployed in 2009/2010 to test atmospheric transmissions in the FIR/submm window (collaboration between PMO and SAO) A 5m THz telescope (~ ) A large (15m) THz telescope (~ ) Jan. 5, 2009 URSI, Boulder, Colorado

11 Key Science for Galactic Astronomy Molecular cloud Stars Planet systems Life cycle of interstellar medium Credit: Walker/Kulesa

12 Science Drivers For 5m THz telescope Origin of molecular clouds Origin of stars Origin of solar system (Asteroid, Comets) Origin of complex molecules Cycle of interstellar medium

13 Herschel: Spectroscopy Orion KL

14 Hershel: Spectroscopy

15 Dense Cores: Physical/Chemical Condition HII, CII H, CI Most molecules depleted at n > 10 6 cm -3. Only H 3+, H 2 D +, D 2 H + Herschel does not cover 1.37THz line

16 Jets from Youngest Class 0 Protostar HH212: The flattened core in C 18 O is infalling and rotating around the star, which drives a jet in H 2 and wide angle outflow in 12 CO: Lee et al HH CO 2-1 C 18 O 2-1 H 2 Different molecular tracers Reveals different part of molecular core/outflow

17 Massive Outflow: IRAS Outflow appears very different from CO 1-0 to CO 7-6 CO 7-6 SiO 2-1 Kawamura et al Shepherd et al Cesaroni et al. 1999

18 Spectroscopy: Hot Core Physics/Chemistry Van Dishoeck and Blake 1998

19 Orion-KL Spectra from SMA Orion-KL: Hot Core L = 10 5 L sun D = 450 pc Beuther et al. Access high-j rotational transitions at THz window All datacubes are smoothed to the same spatial resolution of 5700AU

20 [NII] from SAO THz Telescope (RLT) [N II] 1.46 THz. For localized emission sources (high n), F 205μm / F 122μm = 1/10 G Jun-Jul 2005 (Kawamura et al., submitted)

21 Protoplanetary Disks TW Hydra CO 2-1 CO 3-2 CO 6-5 High J CO Depletion, Deuterated H Qi et al Credit: NASA/Burrows et al.

22 Comets The comet nucleus is at a relatively warm temperature of K, thereby high J rotational lines. With sensitive observations of different molecules, we can obtain molecular composition and kinematic information. HCN 4-3 (845 µm) observed at SMA Chunhua Qi

23 Science Drivers For 15m THz telescope

24 Cloud and Star Formation Structure of molecular clouds, core formation, and life time of prestellar cores Core mass function (CMF) and its relation to stellar IMF Brown dwarf formation Role of magnetic fields

25 Molecular Cloud Survey Mass sensitivity of 0.1 M Jupiter for the Ophiucus cloud Optical Image Extinction Map, Ridge et al.

26 Dust Polarization Magnetic Fields 磁场是恒星形成里的 暗能量 Magnetic field is an essential element in theory of star formation: cloud support, ambipolar diffusion, angular momentum, fragmentation, accretion But we know very little from observations Use dust polarization to study magnetic fields

27 Dust Polarization in NGC 1333 IRAS 4A/B Low mass Class0 protostar in Perseus cloud Minchin, Sandell, Murray 1995 JCMT 800 μm at pc B field direction SMA 2 resolution: Hourglass morphology in B field Girart et al. Science AU Dome A Telescope can map polarization at all scales down to 3 at 200 um

28 Planet Formation How planetary system like ours form?? Protoplanetary disks Debris Disk (β Pic) Solar System

29 Evolution of Protoplanetary Disks IR excess (warm dust at few AU) decreases rapidly over age Rapid mass loss. i.e. disk clearing due to accretion and/or planet formation Can cold dust exist at larger radii??? Survey of young clusters for protoplanetary disks Dust Polarization in disks

30 Debris Disks Solid particles surrounding main sequence stars, especially the young ones ( Myr), produced via collisional grinding of planetesimals in Kuiper belts An unbiased search of hundreds of nearby main sequence stars for disk emission How diverse are planetary systems and where does the Solar System fit into the picture? A key science area for Spitzer, Hershel, JCMT/SCUBA-2, ALMA, JWST τ Ceti ε Eridani Vega(α Lyr) Fomalhaut(α PsA) β Pic

31 Debris disks trace the underlying distribution of planets. The distribution of dust indicates where planets are and what their mass is. Theoretical simulations: Data Wilner et al. (2002)

32 Discover colder disks too faint for Spitzer to have detected Explores outer Kuiper belts (>100 AU) around solar-like stars that are difficult to detect by other means Quantifies debris around lowerluminosity stars Dome A d = 50 pc 30 minute integrations, except Spitzer shorter/typical Herschel confusion noise dominated (15 mjy) Credit: Dowell

33 Summary (I): Star/Planet Formation Probe magnetic field structures in molecular clouds at x10 sensitivity than current single dish telescopes; Survey clouds with sensitivity of 1 M BD and resolution < Jeans Length to distance of 1kpc, studying CMF, and formation of brown dwarfs; Study evolution of protoplanetary and debris disks, probing planet formation Accessing unique spectral lines in the THz window

34 Summary (II): The submm/thz project exploits the Dome A dry site in an under-explored window with an excellent sensitivity and spatial resolution. It presents great opportunity for Chinese astronomy to leap from mm to Tera Hertz! It provides a huge boost in capability for the astronomical community, and will leverage collaborations with international ground based (ALMA, VLT, 30m Class Optical Teescope), and space borne (JWST) facilities. It will make long lasting impact on many fronts of modern astrophysics (Galaxy Formation and Evolution, Star Formation and Evolution, Disks/Exosolar Planets, Solar System, Astrobiology)