Molecular cloud chemistry and the importance of dielectronic recombination
hal.structure.identifier | Columbia Astrophysics Laboratory [CAL] | |
dc.contributor.author | BRYANS, P. | |
hal.structure.identifier | Columbia Astrophysics Laboratory [CAL] | |
dc.contributor.author | KRECKEL, H. | |
hal.structure.identifier | Laboratoire Univers et Théories [LUTH (UMR_8102)] | |
dc.contributor.author | ROUEFF, E. | |
hal.structure.identifier | Observatoire aquitain des sciences de l'univers [OASU] | |
hal.structure.identifier | Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux [L3AB] | |
hal.structure.identifier | Laboratoire d'Astrophysique de Bordeaux [Pessac] [LAB] | |
dc.contributor.author | WAKELAM, Valentine | |
hal.structure.identifier | Fachbereich Physik [Duisburg] | |
dc.contributor.author | SAVIN, D. W. | |
dc.date.issued | 2009 | |
dc.identifier.issn | 0004-637X | |
dc.description.abstractEn | Dielectronic recombination (DR) of singly charged ions is a reaction pathway that is commonly neglected in chemical models of molecular clouds. In this study we include state-of-the-art DR data for He$^+$, C$^+$, N$^+$, O$^+$, Na$^+$, and Mg$^+$ in chemical models used to simulate dense molecular clouds, protostars, and diffuse molecular clouds. We also update the radiative recombination (RR) rate coefficients for H$^+$, He$^+$, C$^+$, N$^+$, O$^+$, Na$^+$, and Mg$^+$ to the current state-of-the-art values. The new RR data has little effect on the models. However, the inclusion of DR results in significant differences in gas-grain models of dense, cold molecular clouds for the evolution of a number of surface and gas-phase species. We find differences of a factor of 2 in the abundance for 74 of the 655 species at times of $10^4$--$10^6$ years in this model when we include DR. Of these 74 species, 16 have at least a factor of 10 difference in abundance. We find the largest differences for species formed on the surface of dust grains. These differences are due primarily to the addition of C$^+$ DR, which increases the neutral C abundance, thereby enhancing the accretion of C onto dust. These results may be important for the warm-up phase of molecular clouds when surface species are desorbed into the gas phase. We also note that no reliable state-of-the-art RR or DR data exist for Si$^+$, P$^+$, S$^+$, Cl$^+$, and Fe$^+$. Modern calculations for these ions are needed to better constrain molecular cloud models. | |
dc.language.iso | en | |
dc.publisher | American Astronomical Society | |
dc.subject.en | astrochemistry — atomic data — atomic processes — ISM: atoms — dust | |
dc.subject.en | extinction — ISM: molecules | |
dc.title.en | Molecular cloud chemistry and the importance of dielectronic recombination | |
dc.type | Article de revue | |
dc.identifier.doi | 10.1088/0004-637X/694/1/286 | |
dc.subject.hal | Physique [physics]/Astrophysique [astro-ph]/Cosmologie et astrophysique extra-galactique [astro-ph.CO] | |
dc.subject.hal | Planète et Univers [physics]/Astrophysique [astro-ph]/Planétologie et astrophysique de la terre [astro-ph.EP] | |
dc.subject.hal | Physique [physics]/Astrophysique [astro-ph]/Planétologie et astrophysique de la terre [astro-ph.EP] | |
dc.identifier.arxiv | 0809.4504 | |
bordeaux.journal | The Astrophysical Journal | |
bordeaux.page | 286-293 | |
bordeaux.volume | 694 | |
bordeaux.issue | 1 | |
bordeaux.peerReviewed | oui | |
hal.identifier | hal-00398339 | |
hal.version | 1 | |
hal.popular | non | |
hal.audience | Internationale | |
hal.origin.link | https://hal.archives-ouvertes.fr//hal-00398339v1 | |
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