Spectral Line Survey with SKA Satoshi Yamamoto and Nami Sakai Department of Physics, The Univ. of Tokyo Tomoya Hirota National Astronomical Observatory of Japan

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.

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

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

Discovery of CCS as a Carrier of U45379 Suzuki et al Laboratory Spectrum Saito et al. 1987

Chemical Evolution of Dense Cores CCS NH 3 CCS NH 3

＋ Caselli et al Ohashi et al. 1999

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

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

Organic Molecules Glycine –From cold to hot cores, comets, planets –From SKA High-band to ALMA

Carbon-Chain Growth in Cold Starless Cores 13 TMC-1 (Taurus Molecular Cloud-1) Longer Chains, PAHs, Small Grains?

14

Lupus 1 Molecular Cloud D ～ 140 pc Here ! 15

Sakai et al. ApJ, 718, L49 (2010) Long Carbon Chains in Lupus-1A

Negative Ions in Lupus-1A First detection of C 4 H - in starless cores

Second TMC-1 !!

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 H C 2 H e  C 2 H + H + H 

CH Observations 20 Narrow and Broad Components TMC-1

Formation Site of Molecular Cloud Taurus Molecular Cloud color ： CI contours ： C 18 O Maezawa et al. 1999, Astrophys. J. 524, L129.

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.