Herschel Extragalactic Legacy Project

Data site

The current data release is DR1, was officially published on May 2021, and is described in Shirley et al., 2021.

Welcome on the section of the Herschel Database in Marseille dedicated to hosting the data products of the Herschel Extragalactic Legacy Project (HELP). For more information about the project, please visit the HELP main web site.

This site contains the individual “flat file” data products. The main HELP data is also available through Virtual Observatory protocols at the Virtual Observatory at susseX (VOX) database.

Data organisation

HELP work relied a lot on the Jupyter notebook technology to achieve some reproducible science goals. The Python notebooks are used both to process our data, to diagnose potential problems with a lot of plots and to document the work. All the pristine and intermediate data files are provided so that everyone can reproduce the work that has been done, even adding new data, new diagnostics or new data processing.

Within HELP, the work was organised in “data management units” (DMU), each one responsible of some specific tasks. The table below lists all the DMUs and their responsibilities. The file products of all the DMUs is available in the data products part that is browsed as a directory. Each DMU has its own folder, generally with a sub-folder per HELP field.

This directory structure is mirrored on GitHub, under the H-E-L-P organisation but with a big difference: the actual data is not stored on GitHub. The data is only present in the data/ sub-folders on HeDaM. GitHub is nevertheless better suited to display the readmes and the notebooks, because it render them in HTML.

DMU# Responsibility Link
0 Pristine catalogues dmu0
1 Masterlist data dmu1
2 Field definitions dmu2
3 Morphologies (Shapes & Sizes) of Objects dmu3
4 Bright Star Mask dmu4
5 Known Star Flag dmu5
6 Optical photometry validation dmu6
7 Optical photometry dmu7
8 Radio data - LOFAR & FIRST/NVSS/TGSS dmu8
9 Radio data - JVLA-DEEP & GMRT-DEEP dmu9
10 Data Fusion dmu10
11 Cross matching MIPS/PACS/SPIRE dmu11
12 Cross Matching LOFAR & FIRST/NVSS/TGSS dmu12
13 Cross Matching JVLA-DEEP & GMRT-DEEP dmu13
14 GALEX data dmu14
15 X-Ray data dmu15
16 WISE Photometry dmu16
17 MIPS Maps dmu17
18 PACS maps dmu18
19 SPIRE maps dmu19
20 MIPS blind photometry dmu20
21 PACS blind photometry dmu21
22 SPIRE blind photometry dmu22
23 Spec-z data dmu23
24 Photo-z dmu24
25 Prior model dmu25
26 XID+ dmu26
27 Empirical models / templates dmu27
28 SED fitting / CIGALE dmu28
29 Radiative transfer models dmu29
30 Missing (supplementary) Sources dmu30
31 Tools see below
32 Merged catalogue dmu32


We developed several tools to process our data and to make it easy to use the database. They are also hosted on GitHub:


Several publications explain the various stages of HELP work: