Published October 3, 2025
| Version v4
Dataset
Open
ASTRA-DESI DR1 Release v0.4
Authors/Creators
- 1. Universidad de los Andes
- 2. Universidad Nacional de Colombia
- 3. Universidad de Antioquia
Description
ASTRA-DESI Data Release 1 (DR1)
This record bundles the ASTRA-DESI DR1 products for the two DESI survey regions (NGC1 and NGC2). Every catalogue is delivered as a compressed FITS binary table (.fits.gz) whose first extension (HDU 1) contains the data. File headers store the keywords RELEASE=DR1 and the corresponding ZONE label for quick checks.
The regions follow the sky boxes defined by Hou et al. (2025, arXiv:2508.09070):
- NGC1 covers 110 ° ≤ RA ≤ 260 ° and -10 ° ≤ DEC ≤ 8 °;
- NGC2 covers 180 ° ≤ RA ≤ 260 ° and 30 ° ≤ DEC ≤ 40 °.
| Tracer | Number of objects |
|---|---|
| BGS | 240,986 |
| LRG | 102,199 |
| ELG | 67,456 |
| QSO | 87,307 |
Directory layout
The archive preserves the NERSC production tree. Top-level folders contain:
- raw/ – merged real and random catalogues per region.
- classification/ – neighbour count summaries per tracer and random iteration.
- probabilities/ – web-type membership probabilities derived from the classification counts.
- pairs/ – sparse list of target pairs used when counting neighbours.
- groups/ – FoF group catalogues for objects classified as filaments and voids.
Naming conventions
raw/zone_REGION.fits.gz– Region NGC1 or NGC2.classification/zone_REGION_classified.fits.gz– combined tracer summary for the region.probabilities/zone_REGION_probability.fits.gz– per-object web-type probabilities.pairs/zone_REGION_pairs.fits.gz– neighbour pairs for the region.groups/zone_REGION_groups_fof_filament.fits.gz– filament FoF groups restricted to data targets.groups/zone_REGION_YY_groups_fof_void.fits.gz– void FoF groups for the random catalogue iterationYYwritten one file per iteration (100 iterations, zero-padded).
Column reference
Raw catalogues (raw/*.fits.gz)
| Column | Type | Description |
|---|---|---|
| TARGETID | int64 | DESI target identifier. |
| RA | float64 | Right ascension in degrees. |
| DEC | float64 | Declination in degrees. |
| Z | float64 | Spectroscopic redshift. |
| XCART, YCART, ZCART | float64 | Comoving Cartesian coordinates (Mpc) computed with the Planck18 cosmology. |
| TRACERTYPE | string | Tracer label with suffix _DATA or _RAND (BGS_BRIGHT, ELG, LRG, QSO). |
| RANDITER | int32 | -1 for real objects, otherwise the random iteration index (0–99). |
Random catalogues mirror the data counts for every tracer and random iteration.
Classification catalogues (classification/*.fits.gz)
| Column | Type | Description |
|---|---|---|
| TARGETID | int64 | Identifier of the central object. |
| RANDITER | int32 | -1 for data rows, otherwise the random catalogue index. |
| ISDATA | bool | True for data rows; False for random iterations. |
| NDATA | int32 | Number of neighbour pairs built from data tracers for this target. |
| NRAND | int32 | Number of neighbour pairs contributed by random tracers. |
| TRACERTYPE | string | Tracer family (BGS_BRIGHT, ELG, LRG, QSO). |
Probability catalogues (probabilities/*.fits.gz)
| Column | Type | Description |
|---|---|---|
| TARGETID | int64 | Identifier of the object. |
| TRACERTYPE | string | Tracer family. |
| PVOID | float32 | Probability of the object being a void class. |
| PSHEET | float32 | Probability of the sheet class. |
| PFILAMENT | float32 | Probability of the filament class. |
| PKNOT | float32 | Probability of the knot class. |
Pair catalogues (pairs/*.fits.gz)
| Column | Type | Description |
|---|---|---|
| TARGETID1 | int64 | Central object in the neighbour pair. |
| TARGETID2 | int64 | Neighbour contributing to the count. |
| RANDITER | int32 | -1 for data pairs, otherwise random catalogue index. |
Group catalogues (groups/*.fits.gz)
| Column | Type | Description |
|---|---|---|
| TRACERTYPE | string | Tracer family with _DATA suffix. |
| TARGETID | int64 | Member identifier. |
| RANDITER | int32 | -1 for data members (DR1 delivers only data groups). |
| WEBTYPE | string | Cosmic web class (filament for data, void for random groups). |
| GROUPID | int32 | FoF group label unique within each region. |
| NPTS | int32 | Number of members in the group. |
| XCM, YCM, ZCM | float64 | Group barycentre in comoving Cartesian coordinates (Mpc). |
| A, B, C | float64 | Semi-axis lengths of the inertia ellipsoid (Mpc) ordered A≥B≥C. |
The group finder is executed separately for each tracer. For this Zenodo bundle we provide filament groups for data (single file) and void groups for random catalogues (one FITS per iteration, RANDITER ≥ 0).
Using the catalogues
- All FITS tables are compressed with
gzip. - Random catalogues use
RANDITERvalues 0–99; filtering onRANDITER >= 0isolates the random iterations. - The Cartesian coordinates assume the Planck18 cosmology provided by
astropy.cosmology.Planck18.
Files
Additional details
Related works
- Cites
- Preprint: arXiv:2404.01124 (arXiv)
Software
- Repository URL
- https://github.com/forero/ASTRA-DESI
- Programming language
- Python , Shell
- Development Status
- Active