Tele-Correlation: Calibrating Shear-Shear Correlation with Real Data
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866915106327101440 |
|---|---|
| author | Shen, Zhi Zhang, Jun Liu, Cong Li, Hekun Wang, Haoran Liu, Zhenjie Sun, Jiarui |
| author_facet | Shen, Zhi Zhang, Jun Liu, Cong Li, Hekun Wang, Haoran Liu, Zhenjie Sun, Jiarui |
| contents | Tele-correlation refers to the correlation of galaxy shapes with large angular separations (e.g., $>100$ degrees). Since there are no astrophysical reasons causing such a correlation on cosmological scales, any detected tele-correlation could disclose systematic effects in shear-shear correlation measurement. If the shear estimators are measured on single exposures, we show that the field distortion (FD) signal associated with the galaxy position on the CCD can be retained and used in tele-correlation to help us directly calibrate the multiplicative and additive biases in shear-shear correlations. We use the DECaLS shear catalog produced by the Fourier\_Quad pipeline to demonstrate this idea. To our surprise, we find that significant multiplicative biases can arise (up to more than 10\%) due to redshift binning of the galaxies. Correction for this bias leads to about 1$σ$ increase of the best-fit value of $S_8$ from $0.760^{+0.015}_{-0.017}$ to $0.777^{+0.016}_{-0.019}$ in our tomography study. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2406_17991 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Tele-Correlation: Calibrating Shear-Shear Correlation with Real Data Shen, Zhi Zhang, Jun Liu, Cong Li, Hekun Wang, Haoran Liu, Zhenjie Sun, Jiarui Cosmology and Nongalactic Astrophysics Tele-correlation refers to the correlation of galaxy shapes with large angular separations (e.g., $>100$ degrees). Since there are no astrophysical reasons causing such a correlation on cosmological scales, any detected tele-correlation could disclose systematic effects in shear-shear correlation measurement. If the shear estimators are measured on single exposures, we show that the field distortion (FD) signal associated with the galaxy position on the CCD can be retained and used in tele-correlation to help us directly calibrate the multiplicative and additive biases in shear-shear correlations. We use the DECaLS shear catalog produced by the Fourier\_Quad pipeline to demonstrate this idea. To our surprise, we find that significant multiplicative biases can arise (up to more than 10\%) due to redshift binning of the galaxies. Correction for this bias leads to about 1$σ$ increase of the best-fit value of $S_8$ from $0.760^{+0.015}_{-0.017}$ to $0.777^{+0.016}_{-0.019}$ in our tomography study. |
| title | Tele-Correlation: Calibrating Shear-Shear Correlation with Real Data |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2406.17991 |