Abstract
This study is devoted to the estimation of dissociation rates for polycyclic aromatic hydrocarbons (PAHs) molecules due to ultraviolet photon absorption. Four methods are used for calculations. Specifically, the rates of dehydrogenation and destruction of the PAH carbon skeleton are calculated. The results obtained by different methods are compared. It is shown that the results differ significantly, and it is impossible unambiguously estimate minimum sizes and the degree of PAH hydrogenation. The results indicate the need to refine the theoretical models of PAH photodissociation and expand the experimental basis of PAH dissociative properties.
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REFERENCES
Allamandola, L.J., Tielens, A.G.G.M., and Barker, J.R., Interstellar polycyclic aromatic hydrocarbons: the infrared emission bands, the excitation/emission mechanism, and the astrophysical implications, Astrophys. J. Suppl. Ser., 1989, vol. 71, pp. 733–775. https://doi.org/10.1086/191396
McGuire, B.A., Burkhardt, A.M., Kalenskii, S., Shingledecker, C.N., Remijan, A.J., Herbst, E., and McCarthy, M.C., Detection of the aromatic molecule benzonitrile (c-C6H5CN) in the interstellar medium, Science, 2018, vol. 359, pp. 202–205. https://doi.org/10.1126/science.aao4890
Burkhardt, A.M., Lee, K.L.K., Changala, P.B., Shingledecker, C.N., Cooke, I.R., Loomis, R.A., Wei, H., Charnley, S.B., Herbst, E., McCarthy, M.C., and McGuire, B.A., Discovery of the pure polycyclic aromatic hydrocarbon indene (c-C9CH8) with GOTHAM Observations of TMC-1, Astrophys. J. Lett., 2021, vol. 913, p. L18. https://doi.org/10.3847/2041-8213/abfd3a
McKay, D.S., Gibson Jr., E.K., Thomas-Keprta, K.L., Vali, H., Romanek, C.S., Clemett, S.J., Chillier, X.D.F., Maechling, C.R., and Zare, R.N., Search for past life on Mars: possible relic biogenic activity in martian meteorite ALH84001, Science, 1996, vol. 273, pp. 924—930. https://doi.org/10.1126/science.273.5277.924
Sandford, S.A., Aléon, J., Alexander, C.M.O.D., Araki, T., Bajt, S., Baratta, G.A., Borg, J., Bradley, J.P., Brownlee, D.E., Brucato, J.R., Burchell, M.J., Busemann, H., Butterworth, A., Clemett, S.J., Cody, G., et al., Organics captured from comet 81P/Wild 2 by the Stardust spacecraft, Science, 2006, vol. 314, no. 5806, pp. 1720–1724.https://doi.org/10.1126/science.1135841
Maragkoudakis, A., Peeters, E., and Ricca, A., Probing the size and charge of polycyclic aromatic hydrocarbons, Mon. Not. R. Astron. Soc., 2020, vol. 494, pp. 642–664. https://doi.org/10.1093/mnras/staa681
Murga, M.S., Kirsanova, M.S., Wiebe, D.S., and Boley, P.A., Orion Bar as a window to the evolution of PAHs, Mon. Not. R. Astron. Soc., 2022, vol. 509, pp. 800–817. https://doi.org/10.1093/mnras/stab3061
Sidhu, A., Tielens, A.G.G.M., Peeters, E., and Cami. J., Polycyclic aromatic hydrocarbon emission model in photodissociation regions-I. Application to the 3.3, 6.2, and 11.2 µm bands., Mon. Not. R. Astron. Soc., 2022, vol. 514, pp. 342–369. https://doi.org/10.1093/mnras/stac1255
Allain, T., Leach, S., and Sedlmayr, E., Photodestruction of PAHs in the interstellar medium I. Photodissociation rates for the loss of an acetylenic group, Astron. Astrophys., 1996, vol. 305, p. 602. https://ui.adsabs.harvard.edu/abs/1996A&A…305…602A/abstract
Montillaud, J., Joblin, C., and Toublanc, D., Evolution of polycyclic aromatic hydrocarbons in photodissociation regions. Hydrogenation and charge states, Astron. Astrophys., 2013, vol. 552, p. A15. https://doi.org/10.1051/0004-6361/201220757
Andrews, H., Candian, A., and Tielens, A.G.G.M., Hydrogenation and dehydrogenation of interstellar PAHs: Spectral characteristics and H2 formation, Astron. Astrophys., 2016, vol. 595, p. A23. https://doi.org/10.1051/0004-6361/201628819
Rice, O.K. and Ramsperger, H.C., Theories of unimolecular gas reactions at low pressures, J. Am. Chem. Soc., 1927, vol. 49, pp. 1617–1629. https://doi.org/10.1021/ja01406a001
Kassel, L.S., Studies in homogeneous gas reactions I, J. Phys. Chem., 1928, vol. 32, pp. 225–242. https://doi.org/10.1021/j150284a007
Tielens, A.G.G.M., Physics and Chemistry of the Interstellar Medium Astronomy, Cambridge: University Press, 2005.
Forst, W., Unimolecular rate theory test in thermal reactions, J. Phys. Chem., 1972, vol. 76, pp. 342–348. https://doi.org/10.1021/j100647a012
Léger, A., D’Hendecourt, L., Boissel, P., and Desert, F.X., Photo-thermo-dissociation. I–A general mechanism for destroying molecules, Astron. Astrophys., 1989, vol. 213, pp. 351–359). https://ui.adsabs.harvard.edu/abs/1989A A…213…351L/abstract
Jochims, H.W., Ruhl, E., Baumgartel, H., Tobita, S., and Leach, S., Size effects on dissociation rates of polycyclic aromatic hydrocarbon cations: laboratory studies and astrophysical implications, Astrophys. J., 1994, vol. 420, pp. 307–317. https://doi.org/10.1086/173560
Berné, O. and Tielens, A.G.G.M., Formation of buckminsterfullerene (C60) in interstellar space, Proc. Natl. Acad. Sci. U.S.A., 2012, vol. 109, pp. 401–406. https://doi.org/10.1073/pnas.1114207108
Simon, V., Rapacioli, M., Rouaut, G., Trinquier, G., and Gadéa, F.X., Dissociation of polycyclic aromatic hydrocarbons: molecular dynamics studies, Phil. Trans. R. Soc. A., 2017, vol. 375, p. 20160195. https://doi.org/10.1098/rsta.2016.0195
Boersma, C., Bauschlicher Jr., C.W., Ricca, A., Mattioda, A.L., Cami, J., Peeters, E., de Armas, F.S., Saborido, G.P., Hudgins, D.M., and Allamandola, L.J., The NASA Ames PAH IR spectroscopic database version 2.00: Updated content, web site, and on(off) line tools, Astrophys. J. Suppl., 2014, vol. 211, p. 8. https://doi.org/10.1088/0067-0049/211/1/8
Bauschlicher Jr., C.W., Ricca, A., Boersma, C., and Allamandola, L.J., The NASA Ames PAH IR spectroscopic database: computational version 3.00 with updated content and the introduction of multiple scaling factors, Astrophys. J. Suppl., 2018, vol. 234, p. 32. https://doi.org/10.3847/1538-4365/aaa019
https://www.astrochemistry.org/pahdb/.
Micelotta, E.R., Jones, A.P., and Tielens, A.G.G.M., Polycyclic aromatic hydrocarbon processing in a hot gas, Astron. Astrophys., 2010, vol. 510, p. A37. https://doi.org/10.1051/0004-6361/200911683
Mathis, J.S., Mezger, P.G., and Panagia, N., Interstellar radiation field and dust temperatures in the diffuse interstellar medium and in giant molecular clouds, Astron. Astrophys., 1983, vol. 128, pp. 212–229. https://ui.adsabs.harvard.edu/abs/1983AA…128…212M/abstract
Draine, B.T. and Li, A., Infrared emission from interstellar dust I. Stochastic heating of small grains, Astrophys. J., 2001, 551, pp. 807–824.https://doi.org/10.1086/320227
Draine, B.T. and Li, A., Infrared emission from interstellar dust IV. The silicate-graphite-PAH model in the post-Spitzer era, Astrophys. J., 2001, vol. 657, pp. 810–837. https://doi.org/10.1086/511055
Goicoechea, J.R., Teyssier, D., Etxaluze, M., Goldsmith, P.F., Ossenkopf, V., Gerin, M., Bergin, E.A., Black, J.H., Cernicharo, J., Cuadrado, S., Falgarone, E., Fuente, A., Hacar, A., Lis, D.C., Marcelino, N., et al., Velocity-resolved [CII] emission and [CII]/FIR map** along Orion with Herschel, Astrophys. J., 2015, vol. 812, p. 75. https://doi.org/10.1088/0004-637X/812/1/75
Kaiser, R.I. and Hansen, N., An aromatic universe—A physical chemistry perspective, J. Phys. Chem. A, 2021, vol. 125, pp. 3826–3840. https://doi.org/10.1021/acs.jpca.1c00606
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This study was supported by the Russian Science Foundation, project no. 18-13-00269.
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Translated by A. Kazantsev
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Murga, M.S., Wiebe, D.S. Uncertainty in Estimates of Dissociation Rates of Polycyclic Aromatic Hydrocarbons in the Interstellar Medium. Bull. Lebedev Phys. Inst. 49, 416–421 (2022). https://doi.org/10.3103/S1068335622120077
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DOI: https://doi.org/10.3103/S1068335622120077