We have identified a great number (more than 1,130,000) of clusters of galaxies, see the catalogs and papers below.
| Name of cluster catalog | Number of clusters | Number of new cluters | Redshift range | Reference |
| WHL09 | 39,668 | 30,537 | 0.05-0.6 | Wen, Z. L., Han, J. L., & Liu, F. S. 2009, ApJS, 193, 197 |
| WHL12 | 132,684 | 84,584 | 0.05-0.8 | Wen, Z. L., Han, J. L., & Liu, F. S. 2012, ApJS, 199, 34 |
| WH15 | 158,103 | 18,625 | 0.05-0.8 | Wen, Z. L., & Han, J. L. 2015, ApJ, 807, 178 |
| WHY18 | 47,600 | 26,125 | 0.025-0.3 | Wen, Z. L., Han, J. L., Yang, F. 2018, MNRAS, 475, 343 |
| WH21 | 21,661 | 15,614 | 0.1-2.0 | Wen, Z. L., & Han, J. L. 2021, MNRAS, 500, 1003 |
| WH22 | 151,244 | 76,826 | 0.1-1.5 | Wen, Z. L., & Han, J. L. 2022, MNRAS, 513, 3946 |
| WH24 | 1,581,179 | 877,806 | <1.5 | Wen, Z. L., & Han, J. L. 2024, ApJS, 272, 39 |
| Total: 1,130,177 |
Clusters of galaxies are merging during the formation of large-scale
structures in the Universe. Based on optical survey data, we identify
a large sample of pre-mergers of galaxy clusters and merging subclusters
in rich clusters. We find 39,382 partners within a velocity difference of 1500
km/s and a projected separation of 5 r500 around 33,126
main clusters, where r500 is the radius of the main cluster.
Based on the galaxy distribution inside rich clusters with more than
30 member galaxy candidates, we identify subclusters by modeling the
smoothed optical distribution with a two-component profile, and a
coupling factor is obtained for merging subclusters in 7845 clusters.
In addition, we find 3446 post-collision mergers according to the
deviations of brightest cluster galaxies from other member galaxies,
most of which have been partially validated by using the Chandra and
XMM-Newton X-ray images. Two new bullet-like clusters have been
identified by using the optical and X-ray images. The large samples of
merging clusters of galaxies presented here are important databases for
studying the hierarchical structure formation, cluster evolution,
and the physics of intergalactic medium.
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Below are the on-line data in this work (see the description in README):
Table1.tar.gz for 33,126 cluster partner systems.
Table2.tar.gz for merging subclusters in 7845 clusters.
Table3.tar.gz for 3446 post-collision mergers.
Based on the DESI Legacy Imaging Surveys released data and available spectroscopic redshifts, we identify 1.58 million clusters of galaxies by searching for the overdensity of stellar mass distribution of galaxies within redshift slices around pre-selected massive galaxies, among which 877,806 clusters are found for the first time. The identified clusters have an equivalent mass of M500>0.47×1014 Msolar with an uncertainty of 0.2 dex. The redshift distribution of clusters extends to z∼1.5, and 338,841 clusters have spectroscopic redshifts. Our cluster sample includes most of the rich optical clusters in previous catalogs, more than 95% massive Sunyaev-Zeldovich clusters and 90% ROSAT and eROSITA X-ray clusters. From the light distributions of member galaxies, we derive the dynamical state parameters for 28,038 rich clusters and find no significant evolution of the dynamical state with redshift. We find that the stellar mass of the brightest cluster galaxies grows by a factor of 2 since z=1.
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The datasets from this paper (see the description in README) include
(1). the photometric redshifts (we publish about 260 million galaxies with reliable photometric redshifts, i.e. σzp ≤ 2Δz) and stellar masses of galaxies in the DESI Legacy Surveys DR10, listed in the Table 1 in the paper (too large and have to be saved in 13 Declination regions):
(2). The 1,581,179 clusters of galaxies identified from DESI Legacy Surveys DR9 and DR10, listed in the Table2 in the paper;
(3). The 15,864,358 member galaxy candidates of the identified clusters in r500 are given here on web .
Using the algorithms in WH21, we estimated photometric redshifts for 105 million galaxies and identified 151,244 clusters of galaxies from the Dark Energy Survey and unWISE, among which 76,826 clusters are newly identified and 30,477 clusters have a redshift z>1.0. We get the redshifts for 45 X-ray clusters and 56 SZ clusters. More than 95% SZ clusters in the sky region have counterparts in our catalogue. We find multiple optical clusters in the line of sight towards about 15% of SZ clusters.
Below are the on-line data in this work (see the description in Readme_DESunWISE):
galaxy_DESunWISE.dat.gz for 105 million galaxies.
cluster_DESunWISE.dat.gz for 151,244 clusters of galaxies.
member_DESunWISE.dat.gz for 2,454,302 member galaxy candidates.
To identify the clusters at high redshifts, we first presented a catalogue of photometric redshifts for 14.68 million massive galaxies derived from the 7-band photometric data of HSC-SSP and the WISE (unWISE catalogue). The stellar masses of galaxies are derived from the infrared magnitude and calibrated by using the COSMOS data. From such a large dataset, we then identified a sample of 21,661 clusters of galaxies in the redshift range of 0.1<z<2.0, among which 5537 clusters have redshifts z>1 and 642 clusters have z>1.5. Our work significantly enlarges the number of clusters at redshifts of z>1. Here, we publish the data of 14.68 million HSC-SSP×unWISE galaxies (7-band magnitudes, photometric redshifts and stellar masses), 21,661 identified clusters and the 372,974 member galaxy candidates.
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On-line data:
Below are the photometric redshift data of 14.68 million HSC-SSP×unWISE galaxies in eight separated regions (see the description in Readme):
In the region outside of the SDSS, only a few thousand clusters have been previously found. We identified 47,600 clusters of galaxies in the redshift range of 0.02<z<0.4 from photometric data of Two Micron All Sky Survey (2MASS), WISE and SuperCOSMOS, among which 26,125 clusters are recognized for the first time and mostly in the sky outside the SDSS area. Our work significantly enlarges the number of clusters in the region outside of the SDSS.
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We published four papers on identification of galaxy clusters from the SDSS data. Before our works, most of known clusters have a low redshift. In 2009, we developed an alogrithm to identify clusters by using photometric redshifts of galaxies and got 39,668 clusters (WHL09) in the redshift range of 0.05<z<0.6 from the SDSS data release 6 (DR6). In 2012, we updated the algorithm and identified 132,684 clusters in the redshift range of 0.05<z<0.8 from the SDSS DR8 covering 14,000 square degree (WHL12). In 2015, we compiled a sample of 1191 clusters at 0.05<z<0.75 with known masses to calibrate a new redshift-independent richness. By including spectroscopic redshifts of the SDSS DR12, we updated the WHL12 cluster catalog and identified additional 25,419 new clusters, mostly at higher redshifts. The combined WHL12 catalog contains 158,103 clusters, which is currently the largest cluster catalog (WH15). In 2018, we combined the SDSS photometric and spectroscopic data with the WISE data, and identified 1959 massive clusters in the redshift range of 0.7<z<1.0 (WH18).
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Based on our cluster identification algorithm, we identified 631, 202, 187 and 737 clusters in the redshift range of 0.1<z<1.6 from public data in the CFHT-wide, CFHT-deep, COSMOS and SWIRE fields. Merging these clusters samples gives 1644 clusters in the four survey fields, of which 1088 are newly identified.
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On-line data are published with the paper.