A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clusters
Abstract The gas mass fraction in galaxy clusters has been widely used to determine cosmological parameters. This method assumes that the ratio of the cluster gas mass fraction to the cosmic baryon fraction ( $$\gamma (z)$$ γ ( z ) ) is constant as a function of redshift. In this work, we look for a...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2021-04-01
|
| Series: | European Physical Journal C: Particles and Fields |
| Online Access: | https://doi.org/10.1140/epjc/s10052-021-09099-4 |
| _version_ | 1818580440751013888 |
|---|---|
| author | Kamal Bora Shantanu Desai |
| author_facet | Kamal Bora Shantanu Desai |
| author_sort | Kamal Bora |
| collection | DOAJ |
| description | Abstract The gas mass fraction in galaxy clusters has been widely used to determine cosmological parameters. This method assumes that the ratio of the cluster gas mass fraction to the cosmic baryon fraction ( $$\gamma (z)$$ γ ( z ) ) is constant as a function of redshift. In this work, we look for a time evolution of $$\gamma (z)$$ γ ( z ) at $$R_{500}$$ R 500 by using both the SPT-SZ and Planck Early SZ (ESZ) cluster data, in a model-independent fashion without any explicit dependence on the underlying cosmology. For this calculation, we use a non-parametric functional form for the Hubble parameter obtained from Gaussian Process regression using cosmic chronometers. We parameterize $$\gamma (z)$$ γ ( z ) as: $$\gamma (z)= \gamma _0(1+\gamma _1 z)$$ γ ( z ) = γ 0 ( 1 + γ 1 z ) to constrain the redshift evolution. We find contradictory results between both the samples. For SPT-SZ, $$\gamma (z)$$ γ ( z ) decreases as a function of redshift (at more than 5 $$\sigma $$ σ ), whereas a positive trend with redshift is found for Planck ESZ data (at more than 4 $$\sigma $$ σ ). We however find that the $$\gamma _1$$ γ 1 values for a subset of SPT-SZ and Planck ESZ clusters between the same redshift interval agree to within $$1\sigma $$ 1 σ . When we allow for a dependence on the halo mass in the evolution of the gas depletion factor, the $$4-5\sigma $$ 4 - 5 σ discrepancy reduces to $$2\sigma $$ 2 σ . |
| first_indexed | 2024-12-16T07:17:38Z |
| format | Article |
| id | doaj.art-a8f75527ebf84a39afc37a9f8b43a330 |
| institution | Directory Open Access Journal |
| issn | 1434-6044 1434-6052 |
| language | English |
| last_indexed | 2024-12-16T07:17:38Z |
| publishDate | 2021-04-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | European Physical Journal C: Particles and Fields |
| spelling | doaj.art-a8f75527ebf84a39afc37a9f8b43a3302022-12-21T22:39:45ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60441434-60522021-04-0181411410.1140/epjc/s10052-021-09099-4A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clustersKamal Bora0Shantanu Desai1Department of Physics, Indian Institute of Technology, HyderabadDepartment of Physics, Indian Institute of Technology, HyderabadAbstract The gas mass fraction in galaxy clusters has been widely used to determine cosmological parameters. This method assumes that the ratio of the cluster gas mass fraction to the cosmic baryon fraction ( $$\gamma (z)$$ γ ( z ) ) is constant as a function of redshift. In this work, we look for a time evolution of $$\gamma (z)$$ γ ( z ) at $$R_{500}$$ R 500 by using both the SPT-SZ and Planck Early SZ (ESZ) cluster data, in a model-independent fashion without any explicit dependence on the underlying cosmology. For this calculation, we use a non-parametric functional form for the Hubble parameter obtained from Gaussian Process regression using cosmic chronometers. We parameterize $$\gamma (z)$$ γ ( z ) as: $$\gamma (z)= \gamma _0(1+\gamma _1 z)$$ γ ( z ) = γ 0 ( 1 + γ 1 z ) to constrain the redshift evolution. We find contradictory results between both the samples. For SPT-SZ, $$\gamma (z)$$ γ ( z ) decreases as a function of redshift (at more than 5 $$\sigma $$ σ ), whereas a positive trend with redshift is found for Planck ESZ data (at more than 4 $$\sigma $$ σ ). We however find that the $$\gamma _1$$ γ 1 values for a subset of SPT-SZ and Planck ESZ clusters between the same redshift interval agree to within $$1\sigma $$ 1 σ . When we allow for a dependence on the halo mass in the evolution of the gas depletion factor, the $$4-5\sigma $$ 4 - 5 σ discrepancy reduces to $$2\sigma $$ 2 σ .https://doi.org/10.1140/epjc/s10052-021-09099-4 |
| spellingShingle | Kamal Bora Shantanu Desai A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clusters European Physical Journal C: Particles and Fields |
| title | A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clusters |
| title_full | A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clusters |
| title_fullStr | A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clusters |
| title_full_unstemmed | A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clusters |
| title_short | A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clusters |
| title_sort | model independent test of the evolution of gas depletion factor for spt sz and planck esz clusters |
| url | https://doi.org/10.1140/epjc/s10052-021-09099-4 |
| work_keys_str_mv | AT kamalbora amodelindependenttestoftheevolutionofgasdepletionfactorforsptszandplanckeszclusters AT shantanudesai amodelindependenttestoftheevolutionofgasdepletionfactorforsptszandplanckeszclusters AT kamalbora modelindependenttestoftheevolutionofgasdepletionfactorforsptszandplanckeszclusters AT shantanudesai modelindependenttestoftheevolutionofgasdepletionfactorforsptszandplanckeszclusters |