Evolution of PAH features from proto-PN to planetary nebulae

1. Evolution of PAH features from proto-PN to planetary nebulae Ryszard Szczerba N. Copernicus Astronomical Center Toruń, Poland

2. NCACTORUN Collaborators Mirek Schmidt (CAMK) Natasza Siódmiak (CAMK) Grażyna Stasińska (LUTH Obs. Paris-Meudon) Cezary Szyszka (UMK)

3. NCACTORUN • F.W. Herschel (1738 -1822) was born in Hanover. • From 1757 he lived in England. • A musician and an astronomer. • In 1781 he discovered Uranus; • He created catalogs of double stars and nebulae; • In 1800 he discovered infrared radiation..... Sir Frederick William Herschel

4. NCACTORUN Discovery of IR radiation.

5. CAMK PANTORUN Dust - INTRODUCTION: • Existence of solid particles was demonstrated by Trumpler (1930) through the measurements of color excess between the photographic (~4300 A) and V (~5500 A) magnitudes. • By the end of 30’s, a l-1 extinction law in the wavelength range 1-3 mm-1had been established. • Greenstein (1938) proposed a power-law size distribution of dust grains (dn(a)/da ~ a-3.6!) in the size range 80A<a<1 cm to explain the l-1extinction law. • The discovery of interstellar polarization stimulated Cayrel & Schatzman (1954) to consider graphite as interstellar dust component (strong optical anisotropy).

6. NCACTORUN Extinction law R=A(V)/E(B-V) N(H)/E(B-V)~5.8 1021 cm-2 (Bohlin et al. 1978)

7. NCACTORUN graphitic structure Graphite is highly anisotropic material

8. CAMK PANTORUN Dust - INTRODUCTION cont.: • Hoyle & Wickramasinghe (1962) proposed that graphite could form in the atmospheres of cool C-stars and be ejected into ISM. • In 1960’s and early 1970’s UV space missions allowed to determine extinction law in the wavelength range 0.2-10 mm-1. • The presence of 2200 A interstellar extinction bump (Stecher 1965) was interpreted as reinforcement of the graphite proposal. However, exact nature of this bump still remains unidentified! • Gilman (1969) proposed that grains around M-type stars are mainly silicates (Al2SiO3, Mg2SiO4, ...). • Interstellar silicates were first detected in emission in Orion Nebula (Stein & Gillett 1969) and in absorption toward the Galactic Center (Hackwell et al. 1970).

9. NCACTORUN amorphous silicate features 9.7mm Si-O stretching mode 18 mm O-Si-O bending mode Dust thermal emission: l[mm] x T[K] = 3000 ISM: T~20 K; lmax~150 mm CS: T~150 K; lmax~20 mm

10. CAMK PANTORUN Dust - INTRODUCTION cont.: • In mid-1970’s the interstellar extinction curve had been determined in the whole wavelengths range & the main dust components had been determined (graphite & silicates). • Mathis et al. (1977) proposed a model of interstellar dust composed of silicates and graphite with grain size distribution dn(a)/da ~ a-3.5 in the size range 50 A < a < 0.25 mm (MRN model): • MRN model is very successful: 1250 citations in ADS (56 in 2005).

11. NCACTORUN MRN model of interstellar dust • Silicates & graphite: • dn(a)/da ~ a-3.5 • 50A<a<0.25 mm

12. CAMK PANTORUN Dust - Very Small Grains (VSGs): • Donn (1968) proposed that particles like Policyclic Aromatic Hydrocarbons (PAHs) may be responsible for the UV interstellar extinction. • Greenberg (1968) first pointed out that VSGs with a heat content comparable to the energy of a single photon, cannot be characterized by an equilibrium temperature but are subject to fluctuations in temperature. Observational arguments that VSGs are present in Interstellar Space:

13. CAMK PANTORUN VSGs in Inter- & CS-stellar Space • The discovery of presolar nanodiamonds(Lewis et al. 1987) and TiC nanocrystals(Bernatowicz et al. 1996). • The ubiquitous distinctive set of „UIR” emission bands @ 3.3, 6.2, 7.7, 8.6 and 11.3 mm (UIR bands were discoverd first by Gillet et al. (1973) in planetary nebulae). This emission can be explained by transiently heating PAHs (e.g model of Li & Draine 2001 for ISM, where UIRs account ~20% of the total power radiated by dust). • The mid-IR emission at l<60 mm, discovered by IRAS (12 & 25 mm bands) and confirmed by COBE-DIRBE and IRTS observations (see e.g. Draine 2003 and references therein). This emission can be explained also by transiently heating PAHs(Weingartner & Draine 2001).

14. NCACTORUN Presolar grains from meteorites

15. NCACTORUN Presolar grains „typical” dust particle (top) Presolar SiC (right)

16. NCACTORUN PAH features in: reflection nebulae

17. NCACTORUN PAHs: aromatic rings + H • Leger & Puget (1984) • Allamandola et al. (1989) • C-H „stretch” @ 3.3 mm • C-C „stretch” @ 6.2 mm • C-C „stretch” @ 7.7 mm • C-H in-plane „bend” @ 8.6 mm • C-H out of plane „bend” @ 11.3 mm for mono H • @ 12.0 mm for duo H • @ 12.7 mm for trio H • @ 13.6 mm for quartet H • aliphatic (chain-like) C-H „stretch” @ 3.4 mm

18. NCACTORUN graphitic structure Graphite is highly anisotropic material

19. NCACTORUN PAH features in: galaxies (top) HII regions (right)

20. PAH features in: NCACTORUN [WR] planetary nebulae: Szczerba et al. (2001) The detection by ISO ofcrystalline silicatesmarks begining of: ASTROCRYSTALOGRAPHY

21. NCACTORUN The mid-IR emission at l<60mm Observed (left) Model (bottom) Weigartner & Draine (2001) For T=15-25 K, emission from „large” grains is lower by several orders of magnitude!

22. CAMK PANTORUN VSGs in Inter- & CS-stellar Space • The far-UV extinction rise(Donn 1968 – see also Kruegel 2003). Dust grains absorbs and scatters light most effectively @l~2pa. • The ”anomalous” Galactic foreground microwave emission in th 10-100 GHz region. Discovered during studies of CMB is probably due to the fats rotation fo nanoparticles (Draine & Lazarian 1998). • The Extended Red Emission (ERE), first discovered in Red Rectangle (Schmidt et al. 1980). The ERE is attributed to PL of (possibly?) crystalline nano-silicon clusters (Witt et al. 1998). • The photoelectric heating of the diffuse ISM. VSGs are more efficient in heating the gas than large grains. VSGs are responsible for > 95% of the total photoelectric heating of the gas in ISM (Weingartner & Draine 2001) .

23. PAHs in LMC: Ciska Markwick-Kemper et al.

24. NCACTORUN PAHs in LMC

25. NCACTORUN 3.3 & 3.4 mm bands in PN: BD+ 30 3639

26. NCACTORUN 7.7 & 8.6 mm bands in PN: BD+ 30 3639

27. NCACTORUN 6.2, 7.7 & 8.6 mm bands in PN: BD+ 30 3639

28. NCACTORUN 7.7 mm band shape in proto-PN:

29. NCACTORUN 6.2 mm band shape in galactic objects

30. NCACTORUN 3.3 mm C-H stretching mode

31. NCACTORUN 6.2 mm C-C stretching mode

32. NCACTORUN 7.7 mm C-C stretching mode

33. NCACTORUN Ratio of 7.7 an 6.2 mm bands

34. NCACTORUN 8.6 mm C-H in-plane bending mode

35. NCACTORUN Correlation between 3.3 & 6.2 mm bands

36. NCACTORUN Correlation between 7.7 & 8.6 mm bands

37. NCACTORUN 3.3 mm band in proto-PN:

38. NCACTORUN 6.2 mm band in proto-PN:

39. NCACTORUN 7.7 mm band in proto-PN:

40. NCACTORUN 8.6 mm band in proto-PN:

41. NCACTORUN Stasińska, Szczerba, Schmidt, Siódmiak „Post-AGB objects as testbeds of nuclosynthesis in AGB stars” submitted to A&A We can investigate chemistry in objects with smaller mass C: smaller uncertainty than in PNe ....

42. NCACTORUN CNO in post-AGB objects

43. NCACTORUN CNO in post-AGB objects