Published October 8, 2025
| Version v5
Dataset
Open
ASTRA-DESI DR1 Release v0.5
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 for all iterations per region.groups/zone_REGION_groups_fof_void.fits.gz– void FoF groups for all random iterations per region.
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. |
| TARGETID | int64 | Member identifier. |
| RANDITER | int32 | Random iteration index. |
| WEBTYPE | string | Cosmic web class. |
| 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. |
| LINKLEN | float64 | FoF linking length. |
| ISDATA | bool | True for data rows; False for random iterations. |
The group finder is executed separately for each tracer. The linking length is computed per tracer and iteration as the cube root of the convex-hull volume per galaxy.
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