Reconstruction of the two-dimensional gravitational potential of galaxy clusters from X-ray and Sunyaev-Zel’dovich measurements
The mass of galaxy clusters is not a direct observable, nonetheless it is commonly used to probe cosmological models. Based on the combination of all main cluster observables, that is, the X-ray emission, the thermal Sunyaev-Zel’dovich (SZ) signal, the velocity dispersion of the cluster galaxies, an...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
12 June 2018
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| In: |
Astronomy and astrophysics
Year: 2018, Volume: 614 |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/201629364 |
| Online Access: | Verlag, Volltext: https://doi.org/10.1051/0004-6361/201629364 Verlag, Volltext: https://www.aanda.org/articles/aa/abs/2018/06/aa29364-16/aa29364-16.html 
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| Author Notes: | C. Tchernin, M. Bartelmann, K. Huber, A. Dekel, G. Hurier, C.L. Majer, S. Meyer, E. Zinger, D. Eckert, M. Meneghetti, J. Merten |
| Summary: | The mass of galaxy clusters is not a direct observable, nonetheless it is commonly used to probe cosmological models. Based on the combination of all main cluster observables, that is, the X-ray emission, the thermal Sunyaev-Zel’dovich (SZ) signal, the velocity dispersion of the cluster galaxies, and gravitational lensing, the gravitational potential of galaxy clusters can be jointly reconstructed.<i>Aims.<i/> We derive the two main ingredients required for this joint reconstruction: the potentials individually reconstructed from the observables and their covariance matrices, which act as a weight in the joint reconstruction. We show here the method to derive these quantities. The result of the joint reconstruction applied to a real cluster will be discussed in a forthcoming paper.<i>Methods.<i/> We apply the Richardson-Lucy deprojection algorithm to data on a two-dimensional (2D) grid. We first test the 2D deprojection algorithm on a <i>β<i/>-profile. Assuming hydrostatic equilibrium, we further reconstruct the gravitational potential of a simulated galaxy cluster based on synthetic SZ and X-ray data. We then reconstruct the projected gravitational potential of the massive and dynamically active cluster Abell 2142, based on the X-ray observations collected with <i>XMM-Newton<i/> and the SZ observations from the <i>Planck<i/> satellite. Finally, we compute the covariance matrix of the projected reconstructed potential of the cluster Abell 2142 based on the X-ray measurements collected with <i>XMM-Newton<i/>.<i>Results.<i/> The gravitational potentials of the simulated cluster recovered from synthetic X-ray and SZ data are consistent, even though the potential reconstructed from X-rays shows larger deviations from the true potential. Regarding Abell 2142, the projected gravitational cluster potentials recovered from SZ and X-ray data reproduce well the projected potential inferred from gravitational-lensing observations. We also observe that the covariance matrix of the potential for Abell 2142 reconstructed from <i>XMM-Newton<i/> data sensitively depends on the resolution of the deprojected grid and on the smoothing scale used in the deprojection.<i>Conclusions.<i/> We show that the Richardson-Lucy deprojection method can be effectively applied on a grid and that the projected potential is well recovered from real and simulated data based on X-ray and SZ signal. The comparison between the reconstructed potentials from the different observables provides additional information on the validity of the assumptions as function of the projected radius. |
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| Item Description: | Gesehen am 09.05.2019 |
| Physical Description: | Online Resource |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/201629364 |