ISSI Team: New generation of databases for interstellar chemical modeling in preparation for HSO and ALMA

                    ALMA Artistic view                                                                                                            HSO Artistic view (© ESO)
                    © ESO - ALMA Division

Goal of the team:

One major question of solar system history concerns the relation between the chemical complexity observed in the interstellar medium and the prebiotic molecules in comets and on Earth during the appearance of life. This question may find some answers during the next ten years because of two future observational instruments: the Herschel Space Observatory (HSO) and the Atacama Large Millimeter Array (ALMA). By giving access to a range of frequencies not accessible from the ground, HSO will certainly permit the detection of many new molecules. In addition to finding new molecules because of its high sensitivity, ALMA will improve our understanding of the conditions of molecular formation in protostars and protoplanetary disks thanks to very high spectral and spatial resolution. In order to understand these future high-quality data, we will need chemical models of much higher quality than those in use today.
To improve existing models so that we can begin to cope with the large amounts of high-quality data obtainable from HSO and ALMA, we need to improve interstellar chemical databases in a variety of ways, but most importantly in the definition of the precision of reaction rate coefficients and branching fractions between different pathways so that accurate uncertainties in the results of models can be determined. To bring about this desired result, we propose to create a group of about ten specialists in the complementary fields of experimental chemical kinetics, ab initio quantum chemical calculations, and the chemical modeling of interstellar clouds. This group will for the first time bring expert opinion to bear on the uncertainties of the rate coefficients contained in the currently existing databases.

Link to the WIKI page (require a password):

Team Members

In total, there are 14 participants from 8 countries:

Neutral-neutral reactivity at low temperature:
1    Prof. Ian Smith (University Chemical Laboratory, UK),
2    Jean-Christophe Loison (Laboratoire de Physico-Chimie Moléculaire, France)
Ion-neutral reactions:
3    Prof. Dieter Gerlich (Technische Universitaet Chemnitz, Germany)
Dissociative recombination:
4    Wolf Dietrich Geppert (Stockholm University, Sweden)
5    Prof. Ewine van Dishoeck (Leiden Observatory, The Netherlands)
Surface chemistry:
6    Liv Hornekaer (University of Aarhus, Denmark)
Theoretical calculations:
7    Dahbia Talbi (Université de Montpellier, France)
8    Evelyne Roueff (LUTH, France)
9    Prof. Jürgen Troe (University of Göttingen, Germany)
Uncertainty analysis methodology:
10   Pascal Pernot (Laboratoire de Chimie Physique, France)
Chemical modeling and databases:
11    Prof. Tom Millar (Queen’s University Belfast, UK),
12    Prof. Eric Herbst (The Ohio State University, USA)
13    Andrew Markwick-Kemper (University of Manchester, UK)
14    Valentine Wakelam (Laboratoire d’Astrophysique de Bordeaux, France)

Other participants:

ISSI Proposal

Download here

First ISSI meeting: 7 to 10 January 2008

Agenda of the meeting: here

Presentations in pdf format to be downloaded here (require a password)

Agenda before the next meeting in December:

January to February: Selection of the most important reactions (Andrew, Tom, Eric, Evelyne, Pascal and Valentine)

March to October: Research on these reactions (Dahbia, Ewine, Wolf, Dieter,
Jürgen, Jean-Christophe and Ian)

October to December: Check the modification in chemical modeling of these next rate coefficients (Andrew, Tom, Evelyne and Valentine)

February to December: Quantification of the importance of H2 formation rate coefficient in dense and diffuse clouds - Improvement of H2 formation in models (Liv, Herma, Evelyne and Valentine)

Pictures of the group at the first ISSI meeting can be found here.

Second ISSI meeting: 7 to 10 January 2008

Agenda of the meeting: here

Presentations in pdf format to be downloaded here (require a password)

Pictures of the second ISSI meeting can be found here.