2. Jonathan Tennyson Physics and Astronomy UCL Paris, Nov 2008 Molecular linelists for extrasolar planets Artist’s impression of HD189733b C. Carreau, ESA

3. Infra red spectrum of an M-dwarf star

4. Planets

5. Triatomic spectra @ 1000 -3000 K Spectra very dense – cannot get T from black-body fit Synthetic spectra require huge databases > 10 6 vibration-rotation transitions per triatomic molecule Intensities often have to be calculated Partition functions also important

6. The DVR3D program suite : triatomic vibration-rotation spectra Potential energy Surface,V(r 1,r 2,  ) Dipole function  (r 1,r 2,  ) J Tennyson, MA Kostin, P Barletta, GJ Harris OL Polyansky, J Ramanlal & NF Zobov Computer Phys. Comm. 163, 85 (2004). www.tampa.phys.ucl.ac.uk/ftp/vr/cpc03

7. H 3 + (H 2 D + ) H 2 O (HDO) HCN/HNC (H 13 CN/ H 13 CN) HeH + NH 3, HCCH, C 3 Linelists completed or under construction @ UCL

8. Viti & Tennyson computed VT2 linelist Partridge & Schwenke (PS), NASA Ames New study by Barber & Tennyson (BT2) Also Ludwig, SCAN, MT, HITEMP....... Computed Water opacity Variational nuclear motion calculations High accuracy potential energy surface Ab initio dipole surface

9. S.A. Tashkun, HiRus conference (2006) Obs: A. Coppalle & P. Vervisch, JQSRT, 35, 121 (1986)

10. Tinetti et al., Nature, 448, 163 (2007) Water, different T-P Water line list: BT2 Barber et al., 2006

11. Confirmation of Water,methane and hazes! Beaulieu et al., 2007 Knutson et al., 2007 Swain et al., 2008 Pont et al., 2007 G. Tinetti (private communication, 2008)

12. Why is ammonia of interest? Present in: ISM, molecular clouds, late-type dwarfs, gas giants, exoplanets, comets etc. NH 3, CH 4, H 2 O etc. in the spectra of exoplanets give additional information about P and T. NH 3 also gives information about their nitrogen chemistry. Accurate modelling of the atmospheres of late- type brown dwarfs, requires an NH 3 line list. Y-dwarfs (search is on) are characterised by NH 3

13. Our Objectives To create an ammonia line list that is complete and accurate enough for inclusion in model atmospheres of Y-dwarfs and exoplanets, and in the subsequent computation of synthetic absorption spectra for these objects with different chemistries, T and log g. To achieve an accuracy for the stronger transitions that will enable individual NH 3 lines to be assigned in the lab and a range of astrophysical objects including cometary coma and the ISM.

14. Experiment: I. Kleiner, L.R. Brown, G. Tarrago et al., J. Mol. Spectrosc. 193, 46 (1999). Absorption spectra of NH 3 at T=300K New Calculations: RJ Barber, S Yurchenko and J Tennyson

15. Hot spectra of NH 3 : Vibrational intensity T = 300 K T = 1000 K T = 1500 K

16. Opacity of cool stars, brown dwarfs & exoplanets Closed shell diatomics: H 2, CO, etc Transition metal diatomics: TiO, FeH, etc Triatomic molecules: H 2 O, HCN, C 3 etc (CO 2, O 3 ) Tetratomic molecule: NH 3, HCCH Pentatomic: CH 4 Dust (other biomarkers eg HNO 3 ?) Requires systematic collaborative project - PoSSO

17. www.worldscibooks.com/physics/p371.html “The best book for anyone who is embarking on research in astronomical spectroscopy” Contemporary Physics (2006)

18. Partition functions are important Model of cool, metal-free magnetic white dwarf WD1247+550 by Pierre Bergeron (Montreal) Is the partition function of H 3 + correct?

19. Partition functions are important Model of WD1247+550 using ab initio H 3 + partition function of Neale & Tennyson (1996)