# Cosmological Constraints from DES Y1 Cluster Abundances and SPT Multi-wavelength data

## Abstract

We perform a joint analysis of the counts of redMaPPer clusters selected from the Dark Energy Survey (DES) Y1 data and multi-wavelength follow-up data collected within the 2500 deg$$^2$$ South Pole Telescope (SPT) SZ survey. The SPT follow-up data, calibrating the richness--mass relation of the optically selected redMaPPer catalog, enable the cosmological exploitation of the DES cluster abundance data. To explore possible systematics related to the modeling of projection effects, we consider two calibrations of the observational scatter on richness estimates: a simple Gaussian model which account only for the background contamination (BKG), and a model which further includes contamination and incompleteness due to projection effects (PRJ). Assuming either a $$\Lambda$$CDM+$$\sum m_\nu$$ or $$w$$CDM+$$\sum m_\nu$$ cosmology, and for both scatter models, we derive cosmological constraints consistent with multiple cosmological probes of the low and high redshift Universe, and in particular with the SPT cluster abundance data. This result demonstrates that the DES Y1 and SPT cluster counts provide consistent cosmological constraints, if the same mass calibration data set is adopted. It thus supports the conclusion of the DES Y1 cluster cosmology analysis which interprets the tension observed with other cosmological probes in terms of systematics affecting the stacked weak lensingmore »

- Authors:

- Publication Date:

- Research Org.:
- SLAC National Accelerator Lab., Menlo Park, CA (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC), High Energy Physics (HEP)

- Contributing Org.:
- DES; SPT

- OSTI Identifier:
- 1712760

- Report Number(s):
- arXiv:2010.13800; FERMILAB-PUB-20-541-AD-AE-SCD; DES-2020-0588

oai:inspirehep.net:1826470

- DOE Contract Number:
- AC02-07CH11359

- Resource Type:
- Journal Article

- Journal Name:
- TBD

- Additional Journal Information:
- Journal Name: TBD

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 79 ASTRONOMY AND ASTROPHYSICS

### Citation Formats

```
Costanzi, M., and et al.
```*Cosmological Constraints from DES Y1 Cluster Abundances and SPT Multi-wavelength data*. United States: N. p., 2020.
Web.

```
Costanzi, M., & et al.
```*Cosmological Constraints from DES Y1 Cluster Abundances and SPT Multi-wavelength data*. United States.

```
Costanzi, M., and et al. 2020.
"Cosmological Constraints from DES Y1 Cluster Abundances and SPT Multi-wavelength data". United States. https://www.osti.gov/servlets/purl/1712760.
```

```
@article{osti_1712760,
```

title = {Cosmological Constraints from DES Y1 Cluster Abundances and SPT Multi-wavelength data},

author = {Costanzi, M. and et al.},

abstractNote = {We perform a joint analysis of the counts of redMaPPer clusters selected from the Dark Energy Survey (DES) Y1 data and multi-wavelength follow-up data collected within the 2500 deg$^2$ South Pole Telescope (SPT) SZ survey. The SPT follow-up data, calibrating the richness--mass relation of the optically selected redMaPPer catalog, enable the cosmological exploitation of the DES cluster abundance data. To explore possible systematics related to the modeling of projection effects, we consider two calibrations of the observational scatter on richness estimates: a simple Gaussian model which account only for the background contamination (BKG), and a model which further includes contamination and incompleteness due to projection effects (PRJ). Assuming either a $\Lambda$CDM+$\sum m_\nu$ or $w$CDM+$\sum m_\nu$ cosmology, and for both scatter models, we derive cosmological constraints consistent with multiple cosmological probes of the low and high redshift Universe, and in particular with the SPT cluster abundance data. This result demonstrates that the DES Y1 and SPT cluster counts provide consistent cosmological constraints, if the same mass calibration data set is adopted. It thus supports the conclusion of the DES Y1 cluster cosmology analysis which interprets the tension observed with other cosmological probes in terms of systematics affecting the stacked weak lensing analysis of optically--selected low--richness clusters. Finally, we analyse the first combined optically-SZ selected cluster catalogue obtained by including the SPT sample above the maximum redshift probed by the DES Y1 redMaPPer sample. Besides providing a mild improvement of the cosmological constraints, this data combination serves as a stricter test of our scatter models: the PRJ model, providing scaling relations consistent between the two abundance and multi-wavelength follow-up data, is favored over the BKG model.},

doi = {},

url = {https://www.osti.gov/biblio/1712760},
journal = {TBD},

number = ,

volume = ,

place = {United States},

year = {2020},

month = {10}

}