1. Unraveling the Mysteries of Complex Interstellar Organic Chemistry Using HIFI Line Surveys Susanna L. Widicus Weaver, Mary L. Radhuber, Jay A. Kroll, Brett A. McGuire, and Jacob C. Laas Department of Chemistry, Emory University Darek C. Lis California Institute of Technology Eric Herbst Ohio State University ^ Observational Spectral

2. Why Molecular Line Surveys? Our Goals: Conduct surveys for many different types of sources Achieve high spectral sensitivity (for new molecule ID) Obtain full picture of chemical, physical conditions for each source Compare results to astrochemical models New astrochemical models attempt to explain formation of complex organics Models require complete chemical, physical picture for input/comparison Physical parameters, abundances often educated guesses Few surveys access differing chemical, physical environments Garrod, Widicus Weaver, & Herbst, ApJ 682, 2008

3. Tracing Chemical Pathways in the ISM H 2 O + h OH + H H 2 + O CH 3 OH + h CH 3 + OH CH 3 O + H CH 2 OH + H NH 3 + h NH 2 + H H 2 CO + h HCO + H HCO + CH 2 OH HOCH 2 CHO(glycolaldehyde) HCO + CH 3 OCH 3 OCHO(methyl formate) HCO + OHHCOOH(formic acid) HCO + CH 3 CH 3 CHO(acetaldehyde) HCO + NH 2 H 2 NCHO(formamide) CH 3 + CH 3 OCH 3 OCH 3 (dimethyl ether) CH 3 + NH 2 CH 3 NH 2 (methyl amine) CH 3 + CH 2 OH CH 3 CH 2 OH(ethanol) CH 2 OH + CH 2 OHHOCH 2 CH 2 OH(ethylene glycol) h H 2 O, CO, CH 3 OH, NH 3, H 2 CO Ice mantle Garrod, Widicus Weaver, & Herbst, ApJ 682, 2008

4. CSO Orion Spectrum 3018 >3-  lines observed 59% of the lines are unassigned! See talk FA05 (Radhuber et al.) for more information.

5. Results of Spectral Analysis Residual = incomplete modeling of complex lineshapes + unassigned lines of known molecules + very weak lines from COMs

6. CSO Line Surveys Full surveys complete for 8 sources, partial surveys complete for 5 more. CH 3 OHHCOOCH 3 & CH 3 OH CH 3 OCH 3 CH 3 OH & CH 3 CN CH 3 OH T a * (K) HCOOCH 3

7. THz Observational Astronomy 480 GHz -1.2 THz 1.4 – 1.9 THz Herschel Space Observatory Launched in 2009 Stratospheric Observatory for Infrared Astronomy Science observations began in 2010 500 GHz – 2.1 THz Atacama Large Millimeter Array Early science observations to begin in 2011 80 GHz – 950 GHz ESO/José Francisco Salgado ESA / AOES Medialab background: HST, NASA/ ESA/ STScI NASA / DLR

8. Upcoming Herschel Observations

9. The Importance of Follow-Up Imaging Studies Friedel and Widicus Weaver, in preparation. Orion-KL = 3 mm continuum observations with CARMA

10. Revealing Chemistry Through Imaging Different COMs have very different spatial distributions. Neill et al., J. Phys. Chem., in press. CARMA + MF1 MethanolFormic acidDimethyl ether Friedel and Widicus Weaver, CARMA, 2008NRAO EVLA Demonstration 2009 Comparison of Methyl Formate in Orion-KL to other COMs

11. http://amandabauer.blogspot.com/2009/08/carma-telescopes.html Proposed CARMA Observations

12. CSO Survey of Orion-KL RMS = 30 mK Integration Time ~ 4 Nights Full ALMA Capability Similar coverage on Orion-KL RMS = 30 mK Integration Time ~ 1 Minute OVRO Survey of Orion-KL RMS = 150 mK Integration Time ~ 27 Nights eVLA Demonstration Science Image courtesy of NRAO https://science.nrao.edu/facilities/evla/earlyscience/demoscience Blake et al. 1987, ApJ 315, 621 Radhuber et al., in preparation. ALMA Changes Everything

13. CSO surveys at 230 GHz 8 GHz spectrometer = More sources in less time HIFI line surveys at 680 GHz & 1.2 THz OT-1 observations 2011/2012 OT-2 proposals due September 15 CARMA imaging at 230 GHz Proposal review this week ALMA imaging at 680 GHz Cycle-0 proposals due June 30 Comparison to models ID molecules that trace gas-phase or grain-surface chemistry Compare relative abundances of isomers, conformers Future observations CSO 345 GHz receiver + 8 GHz spectrometer SOFIA Future Work http://www.nasa.gov/centers/jpl/images/content/391019main_herschel-b-20091002-full.jpg

14. Acknowledgements The Widicus Weaver Group: Brian Hays, Le Zhong, Cate Levey, Jay Kroll, Jake Laas, Brett McGuire, Mary Radhuber, Brandon Carroll, Sophie Lang, Anne Carroll CSO/Caltech: Jonas Zmuidzinas, Tom Phillips, Geoffrey Blake, CSO Staff & TAC HIFI/HEXOS: Ted Bergin, Nathan Crockett, Claudia Comito, Peter Schilke, Martin Emprechtinger, Steve Lord UIUC/CARMA: Doug Friedel NRAO/ALMA: Anthony Remijan