64 th International Symposium on Molecular Spectroscopy June

64 th International Symposium on Molecular Spectroscopy June 22 - 26, 2009 – Columbus, Ohio THE GBT PRIMOS PROJECT – SCIENCE, STATUS AND SUPICIONS Anthony J. Remijan Commissioning Liaison, NAASC Mike Hollis (NASA), Frank Lovas (NIST), & Phil Jewell (NRAO) Atacama Large Millimeter/submillimeter Array Expanded Very Large Array Robert C. Byrd Green Bank Telescope Very Long Baseline Array

The GBT PRIMOS Project: Searching for our Molecular Origins GBT Presentation Outline: – The GBT and the initial justification – Obtaining the Data – Current Status of the Project – Examples of PRIMOS Science – Probabilities for New Molecule Searches PRIMOS Webpage: www. cv. nrao. edu/~aremijan/PRIMOS contact me: aremijan@nrao. edu 2

The Green Bank Telescope B = 740”/ [GHz] – Investigating spatial scales from 12 arcmin to 15 arcsec! 7854 m 2 - ~2 ACRES! At 17 million pounds, it is one of the largest moving structures on land! OFF(2 min)-ON(2 min) GBT

The GBT PRIMOS Project: Searching for our Molecular Origins GBT There are many specific reasons why a deep spectral line survey is important and timely: 1) In practical terms, a sensitive and methodical survey is one of the most efficient ways to detect new species (WI 03, RG 01, RG 02). 2) Large databases of laboratory Image courtesy of NRAO/AUI and Harry Morton spectroscopic transition frequencies exist already. A thorough, sensitive survey would allow astrochemists to utilize these databases to make firm, multi-transition identifications of species. 3) This survey will produce a complete inventory of known interstellar molecules and their transitions and is potentially one of the most important outcomes of this survey. 4) The results will guide further instrumentation development on the GBT.

The GBT PRIMOS Project: Searching for our Molecular Origins GBT Obtaining the Data • Any/all of these data are available NOW and available in many forms 5

GBT The GBT PRIMOS Project: Searching for our Molecular Origins Obtaining the Data Ascii Format “SLi. SE” it 6

The GBT PRIMOS Project: Searching for our Molecular Origins GBT NRAO Archive Search - archive. cv. nrao. edu Project ID # 9

The GBT PRIMOS Project: Searching for our Molecular Origins GBT Current Status of the Project: (Available via Google Docs. . . ) • • • 300 MHz PF 1 – COMPLETE 600 MHz PF 1 – COMPLETE 800 MHz PF 1 – COMPLETE L-Band (1 -2 GHz) – 60% S-Band (2 -3 GHz) – Low Spectral Resolution – COMPLETE - High Spectral Resolution - 60% • • • C-Band (4 -6 GHz) – COMPLETE (May extend to higher Frequencies) X-Band (8 -10 GHz) – COMPLETE (possible to extend to 11. 6 GHz) Ku-Band (12 -15 GHz) – COMPLETE K-Band (17 -26 GHz) - 80% Ka-Band (26 -40 GHz) – Low Spectral Resolution (Quick Look) – COMPLETE - High Spectral Resolution - 26% • Q-Band (40 -50 GHz) – Low Spectral Resolution – 90% - High Spectral Resolution – 10% (optimistic!) 10

The GBT PRIMOS Project: Searching for our Molecular Origins GBT PRIMOS Science Projects: 11

The GBT PRIMOS Project: Searching for our Molecular Origins GBT PRIMOS Science Projects: Continuum antenna temperatures observed with the GBT spectrometer toward Sgr. B 2 (N-LMH). 12

The GBT PRIMOS Project: Searching for our Molecular Origins GBT PRIMOS Science Projects: 13

The GBT PRIMOS Project: Searching for our Molecular Origins GBT PROBABILITY OF NEW DETECTIONS: At the two plots on the right, we show a 200 MHz wide piece of the GBT spectrum at 14 GHz and a similar 200 MHz wide piece of the 12 m spectrum at 140 GHz toward Sgr B 2(N-LMH). In the mm-wave spectrum, nearly every feature that is above the baseline is a spectral line from either a known or unknown molecular species. Thus, when searching for new molecules, low frequency observations not only provide a wider range of physical and chemical environments to explore, but much less spectral line confusion. 14

The GBT PRIMOS Project: Searching for our Molecular Origins GBT Investigating old Detections: At the two plots on the right, we show the original detection of ethylene oxide done with the Haystack Observatory with a 57” beam and the GBT observations of that same transition with an 18” beam. 15

The GBT PRIMOS Project: Searching for our Molecular Origins GBT Investigating old Detections: Here are the original detection of methyl cyanide with the NRAO 43 m (right) and the same transition made with the GBT (bottom). 16

The GBT PRIMOS Project: Searching for our Molecular Origins GBT Summary: There is great importance in conducting this survey w/the GBT The data are available NOW in multiple formats The Project is ~60% complete over all frequencies and ~85% complete from 1 -26 GHz There are many types of science available with this survey beyond new molecule detections. And while there is less line confusion, you will have to deal with a stronger background continuum and multiple velocity components. PRIMOS Webpage: www. cv. nrao. edu/~aremijan/PRIMOS contact me: aremijan@nrao. edu 17