1. Detection of the CCP (X 2  r ) Radical in IRC+10216: A New Interstellar Phosphorus-Containing Species DeWayne T. Halfen Steward Observatory, Arizona Radio Observatory, University of Arizona Dennis Clouthier Department of Chemistry, University of Kentucky Lucy M. Ziurys Departments of Chemistry and Astronomy, Steward Observatory, Arizona Radio Observatory, University of Arizona June 20, 2008

2. The Importance of Phosphorus Phosphorus key component of RNA, DNA (replication), ATP (metabolism), phospholipids (structure) Cosmically rare – 18 th most abundant element Concentrated in biology – 5 th most abundant Found in meteorites in the form of schreibersite (Fe,Ni) 3 P (Pasek & Lauretta 2005) DNA

3. CSE models also predict that P condenses into schreibersite (Fe,Ni) 3 P (Lodders & Fegley 1999)

4. In diffuse clouds, atomic measurements show that phosphorus not depleted onto grains (Lebouteiller et al. 2005) However in dense clouds, only one phosphorus-bearing species found – PN (Ziurys 1987; Turner & Bally 1987) Until very recently, only one phosphorus-containing species confirmed in circumstellar envelopes – CP (Guélin et al. 1990) PN: J = 2  1 Orion-KL Ziurys 1987 Milam et al. 2008 Phosphorus in the ISM

5. In the last year, HCP and PN observed in IRC+10216 and CRL 2688 (Agúndez et al. 2007; Milam et al. 2008), and tentatively PH 3 (Tenenbaum & Ziurys 2008; Agúndez et al. 2008) –AGB star (IRC+10216) and Protoplanetary nebula (PPN: CRL 2688) Phosphorus Species in Carbon-rich Envelopes Milam et al. 2008 PH 3 J K = 1 0  0 0 Tenenbaum & Ziurys 2008

6. In the last year, PO and PN detected in VY CMa (Tenenbaum, Woolf, & Ziurys 2007; Milam et al. 2008) Tenenbaum, Woolf, & Ziurys 2008 Are there more? Milam et al. 2008 Phosphorus Species in Oxygen-rich Envelopes

7. –MW, MMW, and submm data –  = 1/2 and 3/2 spin-orbit ladders, e and f lambda-doublets recorded –Phosphorus hyperfine I(P) = 1/2 observed in MW and MMW regions Halfen, Sun, Clouthier, Ziurys 2008 Recent Laboratory Measurements of CCP CCP (X 2  r ) rotational spectrum measured by Halfen et al. (2008; FC02)

8. Spectroscopic Constants for CCP ParameterMMW B6362.4077(18) D0.0019908(35) H5.0(2.0) x 10 -9 p+2q50.018(17) (p+2q) D -0.01508(11) (p+2q) H 5.93(82) x 10 -7 h485.261(40) hDhD 0.834(16) d632.534(27) rms0.036 Selected Rotational Frequencies of CCP (X 2  r :  = 1/2) JJ JFF F Parity obs obs - calc 1.5  2  1e19011.684-0.001 1  0e19118.7040.001 2  1f19101.205-0.004 1  0f19386.7110.001 2.5  1.5 3  2e31765.646-0.005 2  1e31797.989-0.003 3  2f31832.211-0.003 2  1f31887.334-0.001 10.5  9.511  10e133577.5110.044 10  9e133579.0490.008 11  10f133623.741-0.006 10  9f133625.6000.016 21.5  20.5 a e273489.5120.010 a f273519.557-0.019 32.5  a e413281.401-0.009 a f413287.070-0.009 Rotational spectrum for  = 1/2 state measured down to 2 mm and at cm wavelengths Can very accurately predict 3 mm spectrum as well Accuracy: 1 part in 10 7 -10 8

9. Why IRC+10216 ? –CP, HCP, PN, and tentatively PH 3 all found in this source –Many carbon-chain species, up to C 8 –Multiple analogous carbide molecules: SiC, SiC 2, CS, CCS Search for CCP in IRC+10216 Searched for CCP with ARO 12m on Kitt Peak at 2 and 3 mm KP 12m

10. Searched for four rotational transitions –Each transition split by lambda-doubling –Each transition observed for 25-67 hours –Reached 3  noise level of 1.5-2 mK –Lines only 2.5-3.5 mK –Five out of the eight possible lines cleanly detected –Three other lines blended with known species –P hyperfine not resolved CCP conclusively detected Six P-bearing species in space Halfen, Clouthier, Ziurys 2008

11. Based on observed spectra, used model of Bieging & Tafalla (1993) to determine the abundance and distribution of HCP, PN, CP, and CCP in IRC+10216 (Milam et al. 2008; Halfen et al. 2008) Abundances and Distribution in IRC+10216 HCP and PN formed under equilibrium conditions near the star CP and CCP found in outer shell of the envelope –CCP less abundant, even further from star than CP

12. In CSEs, HCP parent species of CP and possibly CCP HCP + hv  CP + H CP + CCH  CCP + CH CP + C 3 H  CCP + CCH Outer envelope chemistry may be dominated by ion-molecule reactions CCP could also be formed from P + and HCCH P + predicted in outer envelope of IRC+10216 (Agúndez et al. 2007) P + + HCCH  HCCP + + H HCCP + + e   CCP + H CCP Formation in Circumstellar Envelopes

13. Richer phosphorus chemistry than in molecular clouds –Still only PN detected in dense gas Most of P could be depleted onto grains, i.e. in schreibersite –Contradicts results from diffuse clouds More P-containing molecules to be discovered in ISM & CSE Now 5 P-bearing species detected in the CSE of IRC+10216 30% total phosphorus in IRC+10216 in molecules –Based on cosmic P abundance of 3 x 10 -7 IRC+10216 Molecule  s (″) N tot (cm -2 )f (X/H 2 ) PN361 x 10 13 3 x 10 -10 HCP221 x 10 15 3 x 10 -8 PH 3 41 x 10 14 5 x 10 -8 CP26(shell)1 x 10 14 1 x 10 -8 CCP80 (shell)1 x 10 12 1 x 10 -9 Total9 x 10 -8 Summary of Phosphorus Molecules in IRC+10216

14. With new technology, more molecules could be found New ALMA Band 3 receiver at 3mm recently installed on the ARO 12m ~10 fold increase in sensitivity vs. old 3mm receiver 1.4 mK (3  ) after 15 hours New Discoveries with ALMA technology

15. Lucy Ziurys Dennis Clouthier Emmy Tenenbaum Ming Sun Robin Pulliam Lindsay Zack Jessica Dodd Gilles Adande NASA Astrobiology Institute NSF Astronomy and Astrophysics Postdoctoral Fellowship Acknowledgements