Structure, Excitation and Dynamics of the Inner Galactic Interstellar Medium (SEDIGISM) was a survey of molecular lines in the 217–221 GHz range with the SHeFI receiver on the APEX telescope. The key spectral targets were 13CO(2-1) and C18O(2-1). Other transitions include H2CO, CH3OH, SO, SO2, HNCO, HC3N, SiO, but their detection is typically restricted to the densest regions.

The SEDIGISM survey covers a longitude range l = (-60°,+31°) and a latitude range of |b| < 0.5°. The latitude range extends to |b| < 1° towards the Central Molecular Zone (CMZ), to b > −0∘.75 towards the Nessie filament around l=338°, and to b < +0∘.75 towards the RCW 120 region around l=348°. The total survey area is 84 square degrees, and the observations cover the velocity range vlsr=(-200,200) km/s.

The intrinsic angular resolution of the SEDIGISM survey was ~30 arcseconds and the velocity resolution was 0.25 km/s for 13CO(2-1) and C18O(2-1). The typical rms sensitivity per 0.25 km/s channel of the original data cubes was σ(T) ~ 0.8 - 1K.

CADE currently delivers 13CO(2-1) and C18O(2-1) integrated intensity maps of the full SEDIGISM region using the survey's public DR1. To facilitate manipulating the data, the HEALPix maps are also delivered in NSIDE=16384 (no smoothing before).

Healpix maps made by D. Paradis and A. Hughes.

13CO(2-1) C18O(2-1)


If you make use of the SEDIGISM data in your publication please also 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.”


13CO(2-1) Integrated Intensity :

C18O(2-1) Integrated Intensity :


Original WCS Data

Project Website