Introductory remarks Takeshi Oka Department of Astronomy and Astrophysics and Department of Chemistry, The Enrico Fermi Institute, the University of Chicago Good morning. I am delighted that we are finally here together and begin the Royal Society Discussion Meeting on H3+. On behalf of the participants of the Meeting I wish to thank the Royal Society for their great help and support to this Meeting. We have two days of the Royal Society Discussion Meeting and one day of Satellite Meeting. They are equally important and exciting. The poster session too. The Royal Society Discussion Meeting and Satellite Meeting Kavli Centre, February 9, 2012

H3+ We are also celebrating the 100th anniversary of the discovery of H3+ by JJ Thomson, the 42 president of the Royal Society and the third Cavendish Professor. It is truly inspiring that H3+ initially discovered as a tiny dot here 100 years ago is now observed far away at the center of Galaxy and even outer Galaxy. Thomson, J. J. 1911 Rays of positive electricity. Phil. Mag. 21, 225-249. Thomson, J. J. 1912 Further experiments on positive rays. Phil. Mag. 24, 209-253.

Chemistry, astronomy and physics of H3+ Takeshi Oka Mats Larsson Steve Miller Stephan Schlemmer Secretary Ben McCall In initiating these Meetings I was helped by Alex Dalgarno and Sir Harry Kroto. The Meetings have been organized with Mats Larsson, Steve Miller and Stephan Schlemmer. The Royal Society goes with the Britsh system and secretary’s name does not appear on the program, but we operate by the former Soviet system and the secretary Ben McCall had the supreme power. Also last but not least, we have been greatly helped by personnel at the Royal Society particularly by Tracey Wheeler who efficiently and cheerfully took care of the nitty-gritty of the Meetings. Tracey Wheeler

Session 1, Spectroscopy and Theory 3n1+2n2 n1+ 4n24 6n22 2n1+3n2 6n20 n1+ 4n2 5n25 3n1+n2 5n23 5n21 2n1+2n2 4n24 n1+ 3n2 4n22 3n1 4n20 2n1+n2 n1+2n22 3n23 n1+2n20 3n21 2n1 n1+ n2 2n22 Morong et al. 2009 2n20 Gottfried et al. 2003 McCall et al. 2000 n1 n2 Xu et al. 1992 Bawendi et al. 1990 Majewski et al. 1987 Oka 1980

Session 1, Spectroscopy and Theory 10-8 Eh non-adiabatic corr. Jaquet SM Polyansky RSDM Adamowicz RSDM Pavanello, et al. 2012, Phys. Rev. Lett. 108, 023002 ? 3ν1+ 4ν22 16000 ν1+ 6ν24 2ν1+ 5ν21 8ν22 ν1+ 6ν22 Ion counting Petrignani, RSDM Since these are inter-disciplinary Meetings by people with widely different background, I wish to count out some highlights of the subjects of discussions. The spectroscopy started in 1980. Together with the serendipitous discover of H3+ in Jupiter we observed higher transitions. Three years ago we terminated this brcause we ran out of the signal to noise ratio. The highest absorption is about million times weaker than the fundamental to count Here I wish out some highlights of the Meetings so that you can all participate in the discussions. This was pickeup up nicely by the action spectroscopy developed by Schlemmer, Gerlich and others. There has been a paradigm shift from photon counting spectroscopy to ion counting spectroscopy with much higher sensitivity and allowed to go deeply into the visible. This is just beginning and should allow us to do much deeper and to the ultraviolet. Alan Carrington’s spectrum is waiting at 35000 cm-1 still way up in the sky. The theoretical development has been even more spectacular. < 10-6 Eh Photon counting Morong, Gottfried, Oka 2009, JMS, 255, 13 Sub-Doppler Shy, Amano SM, P

Session 2, Chemistry H3+ + O2 → H2 + HO2+ H3+ + N2 → H2 + HN2+ p H3+ + O2 → H2 + HO2+ Schlemmer RSDM He-HO2+, Ne-HO2+ Nizkorodov et al. 1997 CPL, 278, 26 Widucus Weaver et al. 2009 ApJ, 697, 601 H3+ + N2 → H2 + HN2+ ortho-H3+, para-H3+ McCall RSDM Crabtree, Tom, McCall, 2011, J. Chem. Phys. 134, 194310 Crabtree et al. 2011, J. Chem. Phys. 134, 194311 Crabtree et al. 2011, ApJ, 729:15 (12pp) H+ + H2 → H3+ + hν Plasil SM H3+ trapping noble gas Pauzat SM Mousis SM

 L = 2 ke N(H3+) (nC/nH)SV RX / f(H2) Session 3, Dissociative recombination H3+ + e˗ → H + H + H, H2 + H  L = 2 ke N(H3+) (nC/nH)SV RX / f(H2) Oka et al. 2005, ApJ, 632, 882 Cloud length Cosmic ray ionization rate Larsson RSDM Johnsen SM 104 → 3 20 – 30 K McCall et al. 2004, PR A70, 052716 380 K Petrignani et al. 2011, PR A83, 032711 ortho-H3+, para-H3+ Kreckel RSDM Glosik SM Cation + anion Thomas SM H3O+ CH3+ NH4+ Douguet P D3+ Dohnal P Help!!! Theory for H3+ Recombination Badly Needed Oka 2001 Kokooline, Greene, Esry, 2001, Nature, 412, 891 Kokooline, Greene, 2003, Phys. Rev. Lett. 90, 133201 Kokooline, Greene, 2003, Phys. Rev. A68, 012703 Jungen, Pratt, 2009, Phys. Rev. Lett. 102, 023201 Jungen RSDM

Session 4, H3+ as best Probe for Cosmic Rays H → H+ HD, OH H+ + e- → H + hν H2 → H2+ H3+ H3+ + e- → H + H + H ζ 7 × 10-18 s-1 Spitzer Tomasko 1968 Dense cloud ζL = (0.32 – 1.50) × 102 cm s-1 3 × 10-17 s-1 McCall et al. 1999, ApJ, 522, 338 Diffuse cloud ζL = (0.48 – 4.40) × 104 cm s-1 5 × 10-16 s-1 Indriolo et al. 2007 ApJ, 671,1736 Indriolo, McCall, 2012, ApJ, 745, 91 Galactic center ζL > (1.2 – 6.3) × 105 cm s-1 > 2 × 10-15 s-1 Black RSDM Indriolo RSDM

Session 5, Galactic center H3+ warm diffuse cloud Oka et al. 2005, ApJ, 632, 882 Goto et al. 2008, ApJ, 688, 306 Geballe, Oka, 2010, ApJ, 709, L70 T ~ 250 K n < 100 cm-3 Geballe RSDM Goto SM Lis RSDM H3O+ hot dense cloud T ~ 700 K n ~ 104 cm-3 Active Galactic Nucleus Meijerink SM

Session 6, Interstellar Chemistry Gerin RSDM Schilke SM H3+ R(1,1)l H2O+ 111← 000 H2O+ 110← 101 Schilke et al. 2011, A&A, 521, L11 Geballe & Oka, 2010, ApJ, 709, L70 H2+ H3+ H3+ + HD → H2 + H2D+ + 232 K H2D+ + HD → H2 + HD2+ + 187 K HD2+ + HD → H2 + D3+ + 234 K H2 Van der Tak RSDM Pagani RSDM H- (H2-) Robert, Herbst, Millar, 2003, ApJL 591, L41

Session 7, Planetary ionosphere H3+ aurora H3+ aurora Stallard RSDM Io, Volcano Oka, Rev. Mod. Phys. 1992, 64, 1141

Other hydrogenic species H2+ H3 Black RSDM H3˗ Kokoouline SM H5+ Prosmiti SM Valdes P H7+ Prosmiti P H4+ in solid Ne Correnti P H6+ in solid H2 Kumagai P