InterStellar Abundances

Uncritical compilation of observed atomic and molecular abundances in various interstellar environments gathered from the litterature

Where do abundance values come from ?

Abundances come from published articles, each entry is associated with a bibliographic reference.

How come some uncertainty values are missing ?

Quantitative uncertainties are not always associated with abundance measures, refer to the article associated with the abundance value for more details.

How can I submit data ?

You can contact us by email so we can assist you through the process.

Is a webservice provided to fetch abundances ?

Yes, please contact us by email .

How are the abundance defined ?

The abundance [X] of species X is defined as [X] = N(X)/N(Htot) = N(X)/(N(H)+2*N(H2)), where N(X) is the column density of species X