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ZTF DR24 Objects Table - HATS Collection
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Version Date: 2026-05-08

This is an enhanced version of Zwicky Transient Facility's ZTF DR24 Objects Table
(https://irsa.ipac.caltech.edu/data/ZTF/docs/releases/ztf_release_notes_latest), created by IRSA
(http://irsa.ipac.caltech.edu). It is structured as a HATS (Hierarchical Adaptive Tiling Scheme)
Collection and includes three Apache Parquet datasets: HATS Catalog, Margin Cache, and Index Table.
HATS Catalogs are partitioned spatially using an adaptive-order HEALPix (Hierarchical Equal Area
isoLatitude Pixelization) scheme.

For more information about HEALPix and HATS, see
https://irsa.ipac.caltech.edu/docs/parquet_catalogs.

For Python data access examples and tutorials, see https://irsa.ipac.caltech.edu/docs/notebooks/.

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Statistics
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Total size on disk: 1.4 TB

HATS Catalog rows:    8,138,737,715 (same as original ZTF DR24 Objects Table)
HATS Catalog columns: 77 (71 original + 6 HATS/HEALPix)

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Directory Contents
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Basic directory structure:

collection.properties                   HATS Collection properties
ztf_dr24_objects-hats/                  HATS Catalog; main data product
  dataset/                              Parquet dataset
    _common_metadata                    Parquet schema
    _metadata                           Parquet metadata collected from all data files
    partition directories               'Norder', 'Dir', 'Npix'
      parquet files
ztf_dr24_objects-hats_margin_10arcsec/  HATS Margin Cache at 10 arcsec
  dataset/                              Parquet dataset; similar to above
ztf_dr24_objects-hats_index_oid/        HATS Index Table; maps 'oid' column to HATS partitions
  dataset/index/                        Parquet dataset; similar to above

Download scripts:

download-aws-cli.sh         Bulk download from AWS S3 using the AWS CLI
download-irsa-wget.sh       Bulk download from IRSA using wget

HATS metadata files in the Catalog, Margin Cache, and Index Table directories:

hats.properties             HATS dataset properties
partition_info.csv          HATS partition IDs and row counts
skymap.fits                 Row counts per HEALPix order 6 pixel

Additional metadata files in the Catalog, Margin Cache, and Index Table directories:

healpix9_to_partition.txt   Maps HEALPix order 9 ('_healpix_9') to HATS partitions (Catalog only)
linecounts.txt              Row counts per file
md5sums.txt                 MD5 checksums
schema.txt                  Schema in plain text
skymap.png                  Visualization of angular density and HATS partitions (Catalog only)

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Documentation and Acknowledgments
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For complete documentation of Zwicky Transient Facility, please see
https://irsa.ipac.caltech.edu/Missions/ztf.html.

If you use the ZTF DR24 Objects Table, please cite the dataset Digital Object Identifier (DOI):
10.26131/IRSA597 (https://www.ipac.caltech.edu/doi/10.26131/IRSA597). In addition, please follow
the mission's acknowledgement guidelines (https://irsa.ipac.caltech.edu/Missions/ztf.html) and the
IRSA acknowledgement guidelines (https://irsa.ipac.caltech.edu/ack.html). If you use the S3 copy,
also follow the citation instructions at https://registry.opendata.aws/ztf/.

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Contact
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For assistance with this product, please contact IRSA User Support via the Help Desk at
http://irsa.ipac.caltech.edu.