L3S : Large Scale Structure Services
Service d'observation sur les grandes structures en multi-longueurs d'ondes

L3S develops and maintain an expertise in high level analysis of large scale structures, by producing analysis pipelines, distributing data in databases, and offering visualisation of added value products, using uptodate technics from VO and machine learning.

L3S is a Action Nationale d'Observation du centre d'Expertise Régional SO5 des Observatoires des Sciences de l'Univers Paris Saclay ( OSUPS) , de la Cote d'Azur (OCA) et d'Aix Marseille (Pytheas).

Large scale Structures: catalogues

L3S delivers data and services on multiwavelength galaxy clusters, proto-clusters and galaxies. You can query the SZ cluster database (SZDB) to get properties from clusters observed by Planck, SPT, ACT, AMI, CARMA. You can provide a (list of) positions in the sky and find out if it matches with a known cluster, obtain stamped maps in SZ and Xray, and/or run a detection algorithm in Optical data with the MAGYC portal. Herschel cluster and proto-clusters observations are also availbale through the HESIOD database. Finally, GAL-P offers galaxy properties obtained with machine learning around your prefered sky position in our 3D visualisation of DTFE galaxy overdensity.

Large scale structures:

L3S delivers high level products from Planck data like SZ maps in SZDB, polarised frequency, galactic dust and CO maps made with in-house technics in P-maps. You can also access the latest SROLL maps released in temperature and polarisation, in healpix format, derived products obtained from neural network approach. The IRAS all sky survey has also been reprocessed to correct for residual instrumental effects and photometric uncertainties. The Improved Reprocessing of the IRAS Survey (IRIS) is also available.

Codes available

L3S is actively developing and maintaining a large class of software dedicated to data analysis and interpretation :

  • Sanepic Signal And Noise Estimation Procedure Including Correlations
  • SUPREME A SUPer REsolution Mapmaker for Extended emission
  • hpproj Projection of Healpix maps onto a planar grid
  • pyDTFE Density maps in 2D or density cubes in 3D from an input distribution of points with the Delaunay Tesselation Field Estimator


  • L3S resp. :
    • Marian Douspis (OSUPS)
    • Christophe Benoist (OCA)
    • Alexandre Beelen (Pytheas)
  • L3S contrib. :
    • Nabila Aghanim
    • Eric Slezak
    • Victor Bonjean
    • Céline Gouin
  • L3S current support :
    • Marc Dexet
    • Nicolas Bruot
    • Hervé Ballans
    • Elie Soubrié
  • L3S former support :
    • Karin Dassas
    • Thierry Gouttebrosse
    • Imène Lajili
    • Christophe Ordenovic