Structure, Excitation and Dynamics of the Inner Galactic Interstellar Medium

Survey Description

This web page is designed to provide access to the SEDIGISM (Structure, Excitation and Dynamics of the Inner Galactic Interstellar Medium) survey database which houses all of processed survey data and auxiliary data products. This survey is a large scale (84 deg2) spectroscopic survey of the inner Galactic disc (see grey shaded region of the left panel of figure below). The main target lines are the 13CO(2-1) and C18O(2-1) transitions, which have a much lower optical depth than that of the more commonly observed 12CO(1-0) transition. Therefore, they are well suited to trace the moderately dense (n ~ 103 cm-3) molecular gas in the Galactic ISM. The data also cover transitions from other molecules (SO, SiO, HNCO...), typically found in higher density regions, and can be used to probe their physical conditions.

Coverage and Integrated 13CO (2-1) Emission Map

With an angular resolution of 30'' and a 1-sigma sensitivity usually below 1.0 K at 0.25 km s-1 velocity resolution, this survey provides a detailed view of interstellar matter over a wide range of scales, from individual star-forming clumps to giant molecular clouds and complexes.

The data were acquired with the APEX telescope between 2013 and 2016, and have been processed with the GILDAS software. The links below provide access to the data products that form the first public data release (DR1). Any publication (partially) based on SEDIGISM data should refer to the following paper: Schuller et al. (2021).

For more details see the press release and accompanying movie of the survey data.

SEDIGISM Workshop September 15-17th 2021

The first batch of SEDIGISM papers were published at the beginning of the year and the survey data products are publicly available. The focus of this workshop is to provide an up-to-date picture of current work being undertaken with the SEDIGISM data and to discuss future opportunities.

The programme of talks can be found here.

Project Resources

Survey Data Products and Publications

Reference, acknowledgments, and additional information

A detailed description of the SEDIGISM survey and overview of the results is given in Schuller et al. (2021). Please reference this paper in any publication that makes use of SEDIGISM data, and please include the following in the acknowledgment section:

"This publication is based on data acquired with the Atacama Pathfinder Experiment (APEX) under programmes 092.F-9315 and 193.C-0584. APEX is a collaboration among the Max-Planck-Institut fur Radioastronomie, the European Southern Observatory, and the Onsala Space Observatory. The processed data products are available from the SEDIGISM survey database located at, which was constructed by James Urquhart and hosted by the Max Planck Institute for Radio Astronomy."

In addition, any publication making use of the GMC catalogue, cloud masks, or medial axis tables, please reference Duarte-Cabral et al. (2021). If any of the additional information added to the catalogue by subsequent publications was used, please ensure you also refer to the respective article as well.

In case of questions/requests please contact the SEDIGISM Project Management Team (PMT): James Urquhart (Kent), Ana Duarte Cabral (Cardiff) and Dario Colombo (MPIfR); or contact us directly via this mail.

Home Page         IMPRINT         PRIVACY POLICY

Send comments and suggestions to the SEDIGISM Team.