1. Integral field spectroscopy of the Red Rectangle: Unraveling the carrier of the RRBs in 2D. Damian Kokkin, Robert Sharp, Masakazu Nakajima, and Timothy Schmidt

2. The Red Rectangle Central binary: 1915 Nebula: 1973 Distance: 330-710pc Expelling carbon rich material Rich optical spectrum Cohen M., Winckel, H.V., Bond, W.E., Gull, T.R., AJ, 2004, 127, 2362

3. The Red Rectangle Bands Emission features close to DIB wavelengths Exhibit a steep blue edge with a red degraded tail Sarre, Science 269, 1995 Are the DIBs and RRBs from the same carrier molecule?

4. Hi-res IFU spectra of Red Rectangle 2 nights observing at Very Large Telescope (Chile) 28 th -30 th December 2004 5 telescope pointings Integral field unit gives A spectrum per pixel -Can chemically map the nebula!

5. The Red Rectangle bands and C 2 T. W. Schmidt, D. L. Kokkin, S. H. Kable, R. G. Sharp and R. Glinski (2006)

6. v=0 v=1 v=2 v=0 v=1 v=2 a3ua3u d3gd3g 516nm 563nm Swan bands first observed in 1802! Described in 1857 by W. Swan What we are actually seeing

7. C 2 is seen in comets and other things

8. Extending C 2 Observations on RR 27 th and 28 th December 2006 Target band systems: –Swan origin and Δv = +1 –Phillips (2,0) –c-d origin

9. Observational Methodology N E

10. RRBs27 th December 2006 Red2000R5620-61240.492-0.5386x30min 3hrs

11. Further Swan bands of C 2 in the RR

12. C 2 versus stellar emission C2 Swan origin emission Stellar emission

13. Distance from object versus emission 1 5 10

14. More on the RRBs

15. RRBs with distance 15 10

16. Maps from the red arm ERE Emission 5800 Å RRB emission Sodium doublet emission 5850 Å RRB emission

17. The Model Modeling: C2 Swan Origin Assumes C2 is statistical equilibrium with the stellar radiation field. Includes the 6 lowest electronic states and for each of these 0≤υ≤5 and 0≤J≤100 giving 8484 distinct ro-vibronic states for transtions to occur between. Photophysics simulated by a Monte Carlo Markov chain starting in a random state. Modeling: λ5800Å RRB and the C2 Swan Origin The observed fluorescence on Earth At 5arcsec If the oscillator strength of the λ5800Å RRB is 0.01 which is common for most medium to large PAH systems and unity fluorescence yield then the abundance would be larger then C2. This approach the C2 column density when f approaches unity. Rate of any transition

18. Electronic Energy Levels v=0 v=1 v=2 v=0 v=1 v=2 a3Π ua3Π u d3Πgd3Πg v=0 v=1 v=2 X1Σg+X1Σg+ v=0 v=1 v=2 A1ΠuA1Πu Swan system Phillips system v=0 v=1 v=2 b3Σg-b3Σg- Ballik-Ramsay system v=0 v=1 v=2 c3Σu+c3Σu+ c-d system X-a forbidden transitions X-c forbidden transitions

19. Computational Methods core Valence active space external MOLPRO package CASSCF reference states generated aug-cc-pVxZ (x = D, T, Q, 5, 6) Swan system used to validate calculations, then applied aV6Z to other systems: Phillips, Ballik-Ramsay, c-d MRCI: excitations into external space Transition moments calculated by MOLPRO Vibrational wavefunctions obtained from ab initio PESs to calculated state-to-state f-values, Einstein coefficients & radiative lifetimes

20. Swan System - PES DTQ56DTQ56

21. Swan System – Other Properties

22. c-d system Radiative Lifetime: 4.72μs Oscillator Strength: 0.0054

23. Direct observation of c-d system 1% premix of C 2 H 2 in Ar DC Discharge Detection via LIF v=0 v=1 v=2 v=0 v=1 v=2 a3ua3u d3gd3g v=0 v=1 v=2 v=3 c3Σu+c3Σu+

24. High resolution Kokkin, Reilly, Morris, Nakajima, Nauta, Kable, Schmidt, JCP, 125, 231101 (2006)

26. Conclusions Further C 2 swan emission lines were detected in the Red Rectangle. –C 2 Swan origin and Δv = +1 –No detection of Phillips (2,0) and c-d origin Opens modelling opportunities of C 2 in Red Rectangle. Characterise local environment Physical properties of RRBs carrier

27. Acknowledgements Neil Reilly, Scott Kable, Klaas Nauta George Bacskay