J. Plasma Fusion Res. SERIES, Vol.7 (2006) 356-357

Ro-Vibrational Collisional Excitation Database :BASECOL – http://www.obspm.fr/basecol
DUBERNET Marie-Lise, GROSJEAN Alain1 , FLOWER David2 ,ROUEFF Evelyne, DANIEL Fabien, MOREAU Nicolas and DEBRAY Bernard1
Observatoire de Paris-Meudon, 5 Place Janssen, 921195 Meudon, France
1 Observatoire de Besançon, 25000 Besançon, France
2 Department of Physics, University of Durham, UK（Received: 4 October 2004 / Accepted: 4 September 2005）

Abstract
The BASECOL database is presented. The 2004 Version contains bibliographical and numerical data on
collisional ro-vibrational excitation of molecules by H, He and H 2 . It provides collisional rotational and rovibrational excitation rate coeﬃcients for molecules of astrophysical interest, the molecular energy levels anda complete description of the chain of errors. It gives information on current calculations and is designed asa reference database to be used by both astrophysicists and physicists.
Keywords:
database, collision, molecules rotation vibration, excitation
1．Introduction
In view of the scientific preparation of the Heterodyne Instrument for the Far-Infrared on board the Herschel Space Observatory (HSO) [1] and of ALMA [2],particular needs have been pointed out for data on collisional ro-vibrational excitation of molecules by theabundant H, He and H2 species present in interstellar
environments.
These questions were addressed initialy by theBasemol [3] group and a list of fundamental and urgent
molecules was set.
This database, called BASECOL is devoted to collisional ro-vibrational excitation of molecules by colliders such as atom, ion, molecule or electron. An international working group of molecular physicists and astrophysicits involved in the calculations and use of rovibrational cross-sections is planned in order to ensure
the continuity and the quality of the database.

ciated to very precise keywords given back to theuser in the query response),• calculated collisional rates• graphical visualization of collisional rates• fitted and analytic functions of the collisional rates
and the associated coeﬃcients• information on the methods used in the calculationof cross sections and rate coeﬃcients (chain of errors)• energy levels of the molecules (coming from spectroscopic databases or used in the theoretical calculations)
The bibliographic database and the numerical databaseare linked together and are designed using a MySQLSGDB with a PHP interface. The Administration section is extremely flexible with the possibility of adding
new capabilities.
Rate coeﬃcients for the systems given in Table 1 arecurrently available via a restricted access. The data are
fully documented and the quality of the data is assessedin detail. This is a major feature of this database.
All tables have ouput format in HTML or ASCII. The
rate coeﬃcients tables are linked to tables containing
the correspondence between labelling of states and their

2．Content
We are primarily focusing on collisional systems ofinterest for various interstellar cold molecular environment. The database is composed of several parts:• a status page with information about the needs for
astrophysics, the current calculations and experiments being carried out, the possibility to contact
the relevant groups.
• a bibliographic database (papers are read and asso-C 2006 by The Japan Society of Plasma

Science and Nuclear Fusion Research

Corresponding author’s e-mail: marie-lise.dubernet@obspm.fr356

Ro-Vibrational Collisional Excitation Database : BASECOL – http://www.obspm.fr/basecol

Table 1 List of molecules in 2004 version of BASECOL
C3 H2 + He
CS + H2
H2 CO + He
HCO+ + H2

CH3 OH + He, H2
H2 + H, He, H2
HDO + He
SO2 + He

CO + H, He, H2
HD + H, He, H2
OCS, HCS+ + He
HCN, HC3 N + He

quantum numbers and energy levels. They are also
linked to tables containing the corresponding fitted coeﬃcients as well as the fitted functions. A graphic interface allows to visualize calculated rate coeﬃcients forany transition, to compare fitted and calculated rate coeﬃcients and to compare diﬀerents sets of calculations.
This database is intended to be useful to astrophysicists and is maintained by physicists. It also provides alink between astrophysicists and physicists interested incarrying on calculations or experiments. A mailing list
is available and users are encouraged to register.
We are also addressing the issue of compatibility ofthe output of the database within the framework of theH2 O + He, H2
HCl + HeSO, SiO + H2
SiC2 + He

Virtual Observatories [4], in relation both with WEB
tools for spectral analysis and with other databases.
Acknowledgements
The authors acknowledge discussions with J. Cernicharo, A. Faure, P. Valiron, N. Feautrier, A.
Spielfiedel.

[1]
[2]
[3]
[4]

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References
http://www.sron.nl/divisions/lea/hifi/
http://www.alma.nrao.edu/
http://www.lra.ens.fr/∼ pcmi/herschel-alma.html
http://www.ivoa.net