Among the various spectroscopic research fields, the investigation of the phenomena that allow to understand the chemistry of the interstellar medium plays a particularly relevant role. The need of laboratory, experimental as well as computational, investigations in this field is due to the fact that astronomical observations require the knowledge of the spectroscopic parameters involved. For the sake of giving an example, we mention that the recent Herschel, SOFIA and ALMA missions require the accurate knowledge of the transition frequencies in the submillimeter-wave range up to the infrared frequency region for a huge number of molecules, for those of relevance, the so-called “flowers”, as well as for the disturbing species, the so-called “weeds”. The need of the knowledge of the spectroscopic parameters has then led to the set up of various databases, that are continuously updated and enlarged. Among the various spectroscopic techniques, thanks to its intrinsic high resolution, rotational spectroscopy is a powerful tool for studying the chemistry and physics of the atmosphere and interstellar medium. Of interest to this talk is the complementarity of theory and experiment. By means of a few exemplificative cases it will be shown how quantum-chemical calculations can guide and support experiment in the field of astrophysical investigations. For these high-level calculations the requirements are efficient treatment of electron correlation via coupled-cluster theory, basis-set extrapolation techniques, incorporation of core correlation, relativistic as well as vibrational effects together with the use of suitable additivity schemes [1]. The species of interest are here organic molecules, like formic acid [2] and uracil [3], as well as ionic species [4] and radicals [5]. [1] C. Puzzarini, J.F. Stanton, J. Gauss, Int. Rev. Phys. Chem. 29, 273 (2010). [2] G. Cazzoli, C. Puzzarini, S. Stopkowicz, J. Gauss, Astron. Astrophys. 520, A64 (2010). [3] S. Brünken, M.C. McCarthy, P. Thaddeus, P. D. Godfrey, R. D. Brown, Astron. Astrophys. 459, 317 (2006); C. Puzzarini, V. Barone, Phys. Chem. Chem. Phys., submitted (2010). [4] F.F.S. van der Tak, H.S.P. Müller, M.E. Harding, J. Gauss, Astron. Astrophys. 507, 247 (2009). [5] R.J. McMahon, M.C. McCarthy, C.A. Gottlieb, J.B. Dudek, J.F. Stanton, P. Thaddeus, Astrophys. J. 590, L61 (2003).
Astrophysical investigations: the computational and spectroscopic approach / C. Puzzarini. - STAMPA. - (2011), pp. 13-13. (Intervento presentato al convegno WINTER MODELING 2011 tenutosi a Scuola Normale Superiore, PISA nel 13-14 gennaion 2011).
Astrophysical investigations: the computational and spectroscopic approach
PUZZARINI, CRISTINA
2011
Abstract
Among the various spectroscopic research fields, the investigation of the phenomena that allow to understand the chemistry of the interstellar medium plays a particularly relevant role. The need of laboratory, experimental as well as computational, investigations in this field is due to the fact that astronomical observations require the knowledge of the spectroscopic parameters involved. For the sake of giving an example, we mention that the recent Herschel, SOFIA and ALMA missions require the accurate knowledge of the transition frequencies in the submillimeter-wave range up to the infrared frequency region for a huge number of molecules, for those of relevance, the so-called “flowers”, as well as for the disturbing species, the so-called “weeds”. The need of the knowledge of the spectroscopic parameters has then led to the set up of various databases, that are continuously updated and enlarged. Among the various spectroscopic techniques, thanks to its intrinsic high resolution, rotational spectroscopy is a powerful tool for studying the chemistry and physics of the atmosphere and interstellar medium. Of interest to this talk is the complementarity of theory and experiment. By means of a few exemplificative cases it will be shown how quantum-chemical calculations can guide and support experiment in the field of astrophysical investigations. For these high-level calculations the requirements are efficient treatment of electron correlation via coupled-cluster theory, basis-set extrapolation techniques, incorporation of core correlation, relativistic as well as vibrational effects together with the use of suitable additivity schemes [1]. The species of interest are here organic molecules, like formic acid [2] and uracil [3], as well as ionic species [4] and radicals [5]. [1] C. Puzzarini, J.F. Stanton, J. Gauss, Int. Rev. Phys. Chem. 29, 273 (2010). [2] G. Cazzoli, C. Puzzarini, S. Stopkowicz, J. Gauss, Astron. Astrophys. 520, A64 (2010). [3] S. Brünken, M.C. McCarthy, P. Thaddeus, P. D. Godfrey, R. D. Brown, Astron. Astrophys. 459, 317 (2006); C. Puzzarini, V. Barone, Phys. Chem. Chem. Phys., submitted (2010). [4] F.F.S. van der Tak, H.S.P. Müller, M.E. Harding, J. Gauss, Astron. Astrophys. 507, 247 (2009). [5] R.J. McMahon, M.C. McCarthy, C.A. Gottlieb, J.B. Dudek, J.F. Stanton, P. Thaddeus, Astrophys. J. 590, L61 (2003).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
