VALD3 Documentation

About VALD

The VALD database was created in 1995 as the “Vienna Atomic Line Database” and aimed at providing the relevant information for atomic transitions significantly contributing to absorption in stellar spectra.

The primary goals of VALD are to compile accurate and complete lists of spectral lines relevant to stellar atmospheres and spectroscopy, and to evaluate line lists and suggest rankings according to the quality of line data.

What VALD offers

The VALD database provides

• Simple and fast access to individual entries from a wide range of data sources
• Tools to extract and combine data from different sources based on recommended or user defined quality assessments.
• Detailed information on literature references and estimates of data quality

How to become a VALD user

VALD is open for anyone. However, in order to keep track of usage statistics, we ask you to send us your email address and affiliation. If you want to register as a new user, please use the Contact Form.

How to extract data from the VALD database

There are two principal methods of interacting with the VALD database. You can (1) prepare requests with the help of our Web interface, or (2) submit requests directly by email.

In both cases, a request can be one of the following four basic types.

1. Show line
   extracts all information about a few spectral lines within a small wavelength interval from all sources

2. Extract element
   extracts transition data with highest ranking for all lines of a species within a certain wavelength interval

3. Extract all
   same as Extract Element, but for all species contained in VALD

4. Extract stellar
   extracts all spectral lines with highest ranked data producing significant absorption
   for specific stellar atmospheric conditions.

In addition, the output of each request can be customized with the help of personal extraction preferences. More detailed information on the format of these requests and the available configuration options are available through the following links:

• Examples of all request types
• Available output formats and physical units
• User-defined configuration of data quality ranking (web interface only)

Access to the VALD interface

Either through one of the following mirror sites :

• VALD webpage Uppsala

• VALD webpage Vienna - currently unavailable VALD webpage Vienna

• VALD webpage Moscow

Or by sending a request to one of the email addresses below:

• vald@vald.astro.uu.se

• vald3@vald.astro.univie.ac.at

• vald3@vald.inasan.ru

Detailed information on the contents of the VALD database

More detailed and technical information on the content of the database can be found through the following links.

• VALD3 line lists with links to references

• Additional information on molecular line lists

• Air-to-vacuum conversion

Additional information

• Acknowledgement and citation

• Feedback is welcome - please use the Contact Form

• VALD team members

• VALD data providers

Internal information for VALD team