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Published byCornelius Sharp Modified over 9 years ago
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Spectral Line Survey with SKA Satoshi Yamamoto and Nami Sakai Department of Physics, The Univ. of Tokyo Tomoya Hirota National Astronomical Observatory of Japan
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Interstellar Chemistry Molecular Formation under Extreme Condition of Low Temp. and Low Density Various new research fields in chemistry Chemical Evolution during Star Formation Process A useful tool to study star formation processes.
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Interstellar Molecules H 2 CO HCN, HNC, H 2 CO, NH 3, CS, SiO, CN, SO, SO 2 H 3 +, HCO +, HN 2 +, HCS +, C 6 H - HC 3 N, HC 5 N, HC 7 N, HC 9 N, HC 11 N C 2 H, C 3 H, C 4 H, C 5 H, C 6 H, C 8 H, CCS, C 3 S CH 3 OH, HCOOCH 3, (CH 3 ) 2 O, C 2 H 5 CN, CH 3 CHO, HCOOH, C 2 H 5 OH, ~ 140 Species
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Line Survey of TMC-1 with NRO 45 m Kaifu et al. (2004) HC 3 N HC 5 N HC 7 N CCS, CCCS, c-C 3 H, CCO, CCCO, C 4 H 2, etc
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Discovery of CCS as a Carrier of U45379 Suzuki et al. 1984 Laboratory Spectrum Saito et al. 1987
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Chemical Evolution of Dense Cores CCS NH 3 CCS NH 3
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+ Caselli et al. 2002 Ohashi et al. 1999
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Carbon Chains HN 2 +, NH 3 Deuterated Species DCO +, H 2 D + Complex Organic Molecules C → CO ConversionCO Depletion Mantle Evaporation Chemical Evolution of Molecular Clouds
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Carbon-chain Molecules Largest species HC 11 N and next candidates HC 13 N –Rich in cold dark cloud cores –SKA Mid/High-band is better than ALMA band-1 Red: HC 11 N Green: HC 13 N
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Organic Molecules Glycine –From cold to hot cores, comets, planets –From SKA High-band to ALMA
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Carbon-Chain Growth in Cold Starless Cores 13 TMC-1 (Taurus Molecular Cloud-1) Longer Chains, PAHs, Small Grains?
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Lupus 1 Molecular Cloud D ~ 140 pc Here ! 15
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Sakai et al. ApJ, 718, L49 (2010) Long Carbon Chains in Lupus-1A
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Negative Ions in Lupus-1A First detection of C 4 H - in starless cores
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Second TMC-1 !!
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60” L1527 (Tobin et al. 2008) Existence of Various Carbon Chains Eu = 21 K N=9-8, F 2 C6H-C6H- C4HC4H C 5 H, C 6 H, C 4 H 2, HC 5 N, HC 7 N, HC 9 N, C 4 H - etc. Efficient Production of Various Carbon-Chain Molecules around the Protostar Triggered by Evaporation of Methane from Grain Mantles Discovery of Warm Carbon-Chain Chemistry (WCCC) Sakai et al. (2008) e.g.) CH 4 + C + C 2 H 3 + + H C 2 H 3 + + e C 2 H + H + H - - - -
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CH Observations 20 Narrow and Broad Components TMC-1
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Formation Site of Molecular Cloud Taurus Molecular Cloud color : CI contours : C 18 O Maezawa et al. 1999, Astrophys. J. 524, L129.
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Summary SKA should be optimized for nonthermal emission and strong thermal emission including HI and OH. ( Thermal emission: I = 2kν 2 T/c 2 ) DI, CH, H 2 CO, CH 3 OH(maser) are good targets. Nevertheless, observations of molecules are still interesting, because of its high sensitivity.
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