1.  Molecule Search: Summing Lines Demo: Detection of Isotopomers of HC 5 N In 39-48 GHz GBT Survey of TMC Glen Langston (NSF) + Many Students

2. Why Molecules? - Precursors of Life Molecular Chemistry is Dynamic Diagnostic clock of star formation Cloud temperature Image from Tielens (2013), Reviews of Modern Physics, vol. 85, page 1021

3. What Telescope? - GBT a.k.a. Robert C. Byrd Green Bank Telescope 100m Diameter 0.3 to 90 GHz Multi-band Spectrometer Radio Quiet Zone

4. What Molecules? - Carbon Chains Molecules found by Hollis, Jewell, Lovas, Remijan, Mollendal, 2004 Ap. J. Let. 610, L21 Lovas, Remijan, Hollis, Jewell, Snyder (2006) Ap. J. Let. 637, L37

5. Confirm Molecules? - Select Carbon Chains

6. Where? - Taurus Molecular Cloud (TMC) Taurus Region Rich in Molecules Long Carbon Chains found in TMC and several regions https://science.nrao.edu/science/Decadal%20Survey/tech/langston_chemistrymap_TEC_RMS.pdf CO image from Goldsmith, P. F., Heyer, M. H., Narayanan, G., Snell, R. L., Li, D., & Brunt, C., 2008 CO

7. What Data? - GBT 39-48 GHz TMC Survey Soon to be in Ap. J. Supp., with all calibrated data online Spectral Resolution 0.04 km/sec Sensitivity 0.06 K RMS (1 Hour obs.)

8. Where? - TMC Cyanopolyyene Peak HC 5 N HC 5 N H C C C C C N Averaging Lines in velocity to increase SNR

9. What Demo? - Isotopomers of H 13 CC 4 N All Lines Average Line See: Langston, Turner (2007), Ap. J. 658, 455.

10. What Demo? - Isotopomers of HC 13 CC 3 N All LinesAverage line

11. What Demo? - Isotopomers of HC 2 13 CC 2 N All LinesAverage line

12. What Demo? - Isotopomers of HC 3 13 CCN All LinesAverage line

13. What Demo? - Isotopomers of HC 4 13 CN All LinesAverage line

14. What Demo? - Average All Isotopomers HC 5 N 3 HC 5 N lines in this frequency range Peak 3.334 +/- 0.005 K (TB) RMS 0.011 K 5 x 3 HC 5 N Isotopomer lines Peak 0.047 +/- 0.003 K (TB) RMS 0.007 K

15. What Demo! - 12 C/ 13 C 12 C/ 13 C = 71.5 +/- 4.5

16. New Confirmation? - H 2 C 3 HCN 14 Strongest Lines in frequency range. No detection of any individual line. Weighted average shows clear 10 sigma detection.

17. New Confirmation! - H 2 C 3 HCN 0.057 +/- 0.005 Confirmation.

18. New Detection? - Keep Posted Thanks! Great Summer Students NRAO and GBT Staff Astrochemists for Lines and Models. Cologne Database of Molecular Spectroscopy H?C?N THE COLOGNE DATABASE FOR MOLECULAR SPECTROSCOPY, CDMS by H. S. P. Müller, S. Thorwirth, D. A. Roth, and G. Winnewisser; Astron. Astrophys. 370 (2001) L49 – L52. H. S. P. Müller, F. Schlöder, J. Stutzki, and G. Winnewisser, THE COLOGNE DATABASE FOR MOLECULAR SPECTROSCOPY, CDMS: A USEFUL TOOL FOR ASTRONOMERS AND SPECTROSCOPISTS, J. Mol. Struct. 742, 215–227 (2005).