1. MW Spectroscopy of  -Alanine and a Search in Orion-KL Shiori Watanabe ( Kyoto Univ. JAPAN ), Satoshi Kubota, Kentarou Kawaguchi ( Okayama Univ. JAPAN ), Yasuko Kasai ( NICT, JAPAN ), and Takamasa Momose ( UBC, CANADA )

2. Amino acid in ISM The origin of biomolecules Interstellar Medium? Astronomical studies Detection (2003) Reassigned to acetone (2005) [ ]  -alanine: The simplest chiral amino acid Laboratory measurements in 100 and 170 GHz A search in Orion KL by NRO 45m telescope in 100 GHz Glycine: Our objective Previous search

3. 52 ~ 72 GHz; Godfrey et al. (1993) 6 ~ 18 GHz; Blanco et al. (2004) Available spectroscopic data of  -alanine Laboratory Observation Laboratory observations in 100 GHz were indispensable for the definite identification in interstellar medium. Astronomical search Astronomical search at Nobeyama 80 ~ 115 GHz

4. Continuous Molecular Beam Source High J transitions (J = 18 - 24) in 80 ~ 115 GHz Rotational temperature needs to be 50 ~ 100 K  - alanine Low vapor pressure at room temperature Sample has to be heated up moderately. Fresh sample has to be supplied continuously. Molecular beam source Nozzle aperture =  0.4 mm Nozzle Temp. = 250  c Stagnation pressure (Ar) ~ 150 Torr  Rotational temp. ~ 50 K Easily decomposed at high temperatures

5. Laboratory Data 98.216 98.218 98.220 [GHz] 170.610 170.612 170.614 [GHz] 20 2,18 - 19 3,17 18 16,3 - 17 15,2 S/N = 3 ~ 10 J’ K a ’ K c ’  J” K a ” K c ” 17 lines9 lines in 83 - 99 GHz (NRO 45 m) 8 lines in 167 - 177 GHz (IRAM 30 m) Obs. Fitting frequency accuracy = 25kHz

6. Laboratory Data (Frequencies) 1 Transition Predicted [MHz] Observed[MHz] Obs. - Pre. Fitting error {J’Ka’Kc’-J” Ka”Kc” } (Blanco et al.) [MHz]O-C [MHz] 18 1 18 - 17 0 17 83 010.66883 011.028(23) 0.360 0.032 18 1 18 - 17 1 17 83 010.668 0.360 0.033 18 0 18 - 17 0 17 83 010.668 0.360 0.032 18 0 18 - 17 1 17 83 010.668 0.360 0.033 9 8 2 - 8 7 1 84 142.56884 142.520(7) -0.048 0.075 9 8 1 - 8 7 1 84 142.583 -0.063 0.060 9 8 2 - 8 7 2 84 142.687 -0.067-0.044 9 8 1 - 8 7 2 84 142.702 -0.182-0.059 19 1 19 - 18 0 18 87 533.78587 534.136(18) 0.352-0.036 19 1 19 - 18 1 18 87 533.785 0.352-0.035 19 0 19 - 18 0 18 87 533.785 0.352-0.036 19 0 19 - 18 1 18 87 533.785 0.352-0.035 9 9 1 - 8 8 0 88 839.54588 839.350(8) -0.195 0.011 9 9 0 - 8 8 1 88 839.545 -0.195 0.010 19 1 18 - 18 2 17 90 609.21190 609.553(9) 0.342 0.009 19 2 18 - 18 2 17 90 609.216 0.337 0.004 19 1 18 - 18 1 17 90 609.224 0.329-0.004 19 2 18 - 18 1 17 90 609.228 0.325-0.008

7. Laboratory Data (Frequencies) 2 Transition Predicted [MHz] Observed [MHz] Obs. - Pre. Fitting error {J’ Ka’Kc’ -J” Ka”Kc” } (Blanco et al.) [MHz] O-C [MHz] 20 1 10 - 19 0 19 92 056.34492 056.794(6) 0.450-0.003 20 1 10 - 19 1 19 92 056.344 0.450-0.003 20 0 20 - 19 0 19 92 056.344 0.450-0.003 20 0 20 - 19 1 29 92 056.344 0.450-0.003 21 1 21 - 20 0 20 96 578.31196 578.847(13) 0.537 0.009 21 1 21 - 20 1 20 96 578.311 0.537 0.009 21 0 21 - 20 0 20 96 578.311 0.537 0.009 21 0 21 - 20 1 20 96 578.311 0.537 0.009 20 2 18 - 19 3 17 98 218.03898 218.520(6) 0.482 0.127 20 3 18 - 19 3 17 98 218.108 0.412 0.058 20 2 18 - 19 2 17 98 218.233 0.288-0.067 20 3 18 - 19 2 17 98 218.302 0.218-0.137 10 10 1 - 9 9 0 98 970.35898 970.085(7) -0.273 0.018 10 10 0 - 9 9 198 970.358 -0.273 0.018

8. Laboratory Data (Frequencies) 3 Transition Predicted [MHz] Observed [MHz] Obs. - Pre. Fitting error {J’ Ka’Kc’ -J” Ka”Kc” } (Blanco et al.) [MHz] O-C [MHz] 21 12 10 - 20 11 9 167 728.133167 728.282(20) 0.149 0.067 17 17 0 - 16 16 1 169 873.965 169 872.413(4)-1.552 0.027 17 17 1 - 16 16 0 169 873.965-1.552 0.027 18 16 3 - 17 15 2 170 612.698 170 611.501(7)-1.198-0.027 18 16 2 - 17 15 3 170 612.698-1.198-0.027 19 15 5 - 18 14 4 171 335.509171 334.693(11)-0.817-0.026 19 15 4 - 18 14 5 171 335.509-0.817-0.026 20 14 7 - 19 13 6 172 018.206 172 017.774(15)-0.432 0.005 20 14 6 - 19 13 7 172 018.215-0.440-0.004 18 17 1 - 17 16 2 175 307.893175 306.408 (4)-1.486 0.022 18 17 2 - 17 16 1 175 307.893-1.486 0.022 19 16 4 - 18 15 3 176 041.083 176 039.962 (7)-1.122-0.032 19 16 3 - 18 15 4 176 041.083 -1.122-0.032 20 15 6 - 19 14 5 176 750.314 176 749.596 (14)-0.718-0.019

9. Molecular Constants Least square fitting error ~  = 42 kHz Blanco et al. A / MHz5066.14612(14)5066.14560(42) B / MHz3100.94994(10)3100.95058(29) C / MHz2264.013439(67)2264.01342(24)  J / kHz 2.4248(26) 2.452(13)  JK / kHz  6.340(11)  6.391(31)  K / kHz 5.4773(92) 5.410(79)  J / kHz 0.5637(12) 0.5696(31)  K / kHz 10.293(10) 10.3777(54) This study Laboratory data freq. – Calculated freq. < 0.14 MHz Spectra were analyzed by the Watson A- reduced Hamiltonian

10. Astronomical Search Abundance of  -alanine could be higher than that in other region. Object OrionKL Organic molecules (HCOOH, CH 3 OH, etc. ) N-containing molecules (NH 2, HCN, NH 2 CHO, etc. ) Hot molecular core (LTE at 100 K) Chemically rich

11. Signal Estimation r.m.s. noise: T b ~ 10 mK OrionKL Column density (estimation): [  -alanine] = [Z] x 10 -1~-2 = 2 x 10 14 cm -2 Z = {HCOOH, HCN, alcohols etc.} T b ~ 30 mK Search by the Nobeyama 45 m telescope 140 hours observation Estimated signal intensity: LTE condition (T ex = 100 K)

12. Searched Transitions Transition (J’ Ka’Kc’ - J” Ka”Kc” ) Lab. Freq. [MHz] Pred. Freq. [MHz] 22 0,22 - 21 1,21 22 1,22 - 21 0,21 101100.3 23 0,23 - 22 1,22 23 1,23 - 22 0,22 105621.0 18 0,18 - 17 1,17 18 1,18 - 17 0,17 107261.0 18 0,18 - 17 1,17 18 1,18 - 17 0,17 109100.4 18 0,18 - 17 1,17 18 1,18 - 17 0,17 110141.1 Transition (J’ Ka’Kc’ - J” Ka”Kc” ) Lab. Freq. [MHz] Pred. Freq. [MHz] 18 0,18 - 17 1,17 18 1,18 - 17 0,17 83011.0 20 1,19 - 19 2,18 20 2,19 - 19 1,18 95132.6 21 0,21 - 20 1,20 21 1,21 - 20 0,20 96578.8 20 2,18 - 19 3,17 20 3,18 - 19 2,17 98218.5 Searched for 9 lines in 83 - 110 GHz

13. Astronomical Data 96 GHz 95 GHz 83 GHz 105 GHz 101 GHz 107 GHz 110 GHz 109 GHz 98 GHz 2. Weak peaks may exist, but two velocity components at 6 and 7.5 km/s 3. Intensities are not consistent with LTE predictions 1. No clear peaks except at 110 GHz 100mK Tb

14. Upper Limit of Column Density Upper limit of column density ca. 10 14 cm -2 LTE at 100 K Line width = 6 km/s OrionKL r.m.s. noise: T b ~ 10 mK Nobeyama 45 m telescope

15. Conclusions Acknowledgement Nobeyama Radio Observatory Laboratory measurements Molecular constants were sufficiently determined for astronomically observations in the 100 GHz region. Astronomical observations No clear peaks of  -alanine were detected. Upper limit of  -alanine in OriKL were determined as ~10 14 cm -2