DESI group/cluster catalogs, shear catalogs

1% spectroscopic data incorporated. 

DESI group/cluster catalogs

We (Yang2021) extend the halo-based group finder developed by Yang et al. (2005b) to use data simultaneously with either photometric or spectroscopic redshifts. A mock galaxy redshift surveys constructed from a high-resolution N-bodey simulation is used to evaluate the performance of this extended group finder. For galaxies with magnitude z<21 and redshift 0 < z < 1.0 in the DESI legacy imaging surveys (The Legacy Surveys), our group finder successfully identifies more than 60% of the members in about 90% of halos with mass >10^12.5Msun/h. Detected groups with mass > 10^12.0Msun/h have a purity (the fraction of true groups) greater than 90%. The halo mass assigned to each group has an uncertainty of about 0.2 dex at the high mass end > 10^13.5Msun/h and 0.45 dex at the low mass end. Groups with more than 10 members have a redshift accuracy of ~ 0.008. We apply this group finder to the Legacy Surveys DR8 and find 5.1 Million groups with at least 3 members. Below we provide the resulting catalog containing 3D coordinates, richness, halo masses, and total group luminosities.

DESI Image Legacy Surveys DR8

Shown in the following plot is the projected galaxy distribution in terms of sky coverage in the the Legacy Surveys DR8. The sky coverage are drawn from two contiguous areas: the south galactic cap (~8580 square degrees with 59.6 million galaxies) and the north galactic cap (~9673 square degrees with 69.75 million galaxies). The color code is the galaxy number counts per 0.25 square degrees.

Legacy Surveys DR8 Readme Galaxy catalogue Group catalogue Member ID

DESI Image Legacy Surveys DR9

Shown in the following plot is the projected galaxy distribution in terms of sky coverage in the the Legacy Surveys DR9. The sky coverage are drawn from two contiguous areas: the south galactic cap (~8601 square degrees with 59.07 million galaxies) and the north galactic cap (~9622 square degrees with 66.23 million galaxies). The color code is the galaxy number counts per 0.25 square degrees.

Legacy Surveys DR9 Readme Galaxy catalogue Group catalogue Member ID

With DESI 1% spectroscopic redshifts -- available for those DESI collaborators upon request.

... Will be public once the DESI redshifts are made public.

In this version, we have incorporated the 1% DESI spectroscopic redshifts into our galaxy sample and updated the related group catalogs.

Shown in the following plot is the projected galaxy distribution in terms of sky coverage in the the Legacy Surveys DR9. The updated redshifts on the sky are marked with green color.

References

A Halo-Based Galaxy Group Finder: Calibration and Application to the 2dFGRS
Yang X., Mo H.J., van den Bosch F.C., Jing Y.P., 2005b, MNRAS, 356, 1293

Galaxy Groups in the SDSS DR4. I. The Catalogue and Basic Properties
Yang X., Mo H.J., van den Bosch F.C., Pasquali A., Li C., Barden M., 2007, ApJ, 671, 153

Evolution of the Galaxy-Dark Matter Connection and the Assembly of Galaxies in Dark Matter Halos
Yang X., Mo H.J., van den Bosch F.C.,Zhang Youcai, Han Jiaxin, 2012, ApJ, 752, 41

An Extended Halo-based Group/Cluster Finder: Application to the DESI Legacy Imaging Surveys DR8
Yang, Xiaohu; Xu, Haojie; He, Min; Gu, Yizhou; Katsianis, Antonios; Meng, Jiacheng; Shi, Feng; Zou, Hu; Zhang, Youcai; Liu, Chengze; Wang, Zhaoyu; Dong, Fuyu; Lu, Yi; Li, Qingyang; Chen, Yangyao; Wang, Huiyuan; Mo, Houjun; Fu, Jian; Guo, Hong; Leauthaud, Alexie; Luo, Yu; Zhang, Jun; Zu, Ying, 2021, ApJ, 909, 143

DESI Shear catalogs

We use the Fourier Quad pipeline to generate the shear catalog for each individual exposure of the DECaLS data. The latest version of our shear catalog contains 15420/15162/16501 exposures for the g/r/z band respectively. The shear catalogs in g/r/z band cover about 10000 square degrees, as shown in the figure. It includes shear estimators for 99/111/116 million distinct galaxies in the band of g/r/z respectively.

References

Approaching the Cramér-Rao Bound in Weak Lensing with PDF Symmetrization
Zhang, Jun; Zhang, Pengjie; Luo, Wentao, 2017, ApJ, 834, 8

Testing Shear Recovery with Field Distortion
Zhang, Jun; Dong, Fuyu; Li, Hekun; Li, Xiangchong; Li, Yingke; Liu, Dezi; Luo, Wentao; Fu, Liping; Li, Guoliang; Fan, Zuhui, 2019, ApJ, 875, 48

The clustering of galaxies in the DESI Legacy Imagining Surveys DR8: II. sigma8 increases as a function of redshift
Haojie Xu, Jun Zhang, Xiaohu Yang, Zhaoyu Wang, Hekun Li, Yao Ji, Pengjie Zhang, Antonios Katsianis, and etc

Mock DESI Galaxy and Group Catalogues

This is a mini version of mock DESI catalogs with only about 200 square degrees.

mini Mock DESI Readme Galaxy catalogues Group catalogues

References

Populating dark matter haloes with galaxies: comparing the 2dFGRS with mock galaxy redshift surveys
Yang, Xiaohu; Mo, H. J.; Jing, Y. P.; van den Bosch, Frank C.; Chu, YaoQuan, 2004, MNRAS, 350, 11

ELUCID. VI. Cosmic Variance of the Galaxy Distribution in the Local Universe
Chen, Yangyao; Mo, H. J.; Li, Cheng; Wang, Huiyuan; Yang, Xiaohu; Zhou, Shuang; Zhang, Youcai, 2019ApJ...872..180C

An Extended Halo-based Group/Cluster Finder: Application to the DESI Legacy Imaging Surveys DR8
Yang, Xiaohu; Xu, Haojie; He, Min; Gu, Yizhou; Katsianis, Antonios; Meng, Jiacheng; Shi, Feng; Zou, Hu; Zhang, Youcai; Liu, Chengze; Wang, Zhaoyu; Dong, Fuyu; Lu, Yi; Li, Qingyang; Chen, Yangyao; Wang, Huiyuan; Mo, Houjun; Fu, Jian; Guo, Hong; Leauthaud, Alexie; Luo, Yu; Zhang, Jun; Zu, Ying, 2021, ApJ, 909, 143

Comments to:  xyang@sjtu.edu.cn