We use measurements from the South Pole Telescope (SPT) Sunyaev–Zel’dovich (SZ) cluster survey in combination with X-ray measurements to constrain cosmological parameters. We present a statistical method that fits for the scaling relations of the SZ and X-ray cluster observables with mass while jointly fitting for cosmology. The method is generalizable to multiple cluster observables, and self-consistently accounts for the effects of the cluster selection and uncertainties in cluster mass calibration on the derived cosmological constraints. We apply this method to a data set consisting of an SZ-selected catalog of 18 galaxy clusters at z > 0.3 from the first 178 deg2 of the 2500 deg2 SPT-SZ survey, with 14 clusters having X-ray observations from either Chandra or XMM-Newton. Assuming a spatially flat ΛCDM cosmological model, we find the SPT cluster sample constrains σ8(Ωm/0.25)0.30 = 0.785 ± 0.037. In combination with measurements of the cosmic microwave background (CMB) power spectrum from the SPT and the seven-year Wilkinson Microwave Anisotropy Probe data, the SPT cluster sample constrains σ8 = 0.795±0.016 and Ωm = 0.255±0.016, a factor of 1.5 improvement on each parameter over the CMB data alone. We consider several extensions beyond the ΛCDM model by including the following as free parameters: the dark energy equation of state (w), the sum of the neutrino masses (Σmν ), the effective number of relativistic species (Neff), and a primordial non-Gaussianity (fNL). We find that adding the SPT cluster data significantly improves the constraints on w and Σmν beyond those found when using measurements of the CMB, supernovae, baryon acoustic oscillations, and the Hubble constant. Considering each extension independently, we best constrain w = −0.973 ± 0.063 and the sum of neutrino masses Σmν < 0.28 eV at 95% confidence, a factor of 1.25 and 1.4 improvement, respectively, over the constraints without clusters. Assuming a ΛCDM model with a free Neff and Σmν , we measure Neff = 3.91 ± 0.42 and constrain Σmν < 0.63 eV at 95% confidence. We also use the SPT cluster sample to constrain fNL = −220±317, consistent with zero primordial non-Gaussianity. Finally, we discuss the current systematic limitations due to the cluster mass calibration, and future improvements for the recently completed 2500 deg2 SPT-SZ survey. The survey has detected ∼500 clusters with a median redshift of ∼0.5 and a median mass of ∼2.3 × 1014 M h−1 and, when combined with an improved cluster mass calibration and existing external cosmological data sets will significantly improve constraints on w.
Cosmological constraints from sunyaev-zel'dovich-selected clusters with X-ray observations in the first 178 deg 2 of the south pole telescope survey / Benson, B. A.; De Haan, T.; Dudley, J. P.; Reichardt, C. L.; Aird, K. A.; Andersson, K.; Armstrong, R.; Ashby, M. L. N.; Bautz, M.; Bayliss, M.; Bazin, G.; Bleem, L. E.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Cho, H. M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; Desai, S.; Dobbs, M. A.; Foley, R. J.; Forman, W. R.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Halverson, N. W.; Harrington, N.; High, F. W.; Holder, G. P.; Holzapfel, W. L.; Hoover, S.; Hrubes, J. D.; Jones, C.; Joy, M.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Liu, J.; Lueker, M.; Luong-Van, D.; Mantz, A.; Marrone, D. P.; Mcdonald, M.; Mcmahon, J. J.; Mehl, J.; Meyer, S. S.; Mocanu, L.; Mohr, J. J.; Montroy, T. E.; Murray, S. S.; Natoli, T.; Padin, S.; Plagge, T.; Pryke, C.; Rest, A.; Ruel, J.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Shaw, L.; Shirokoff, E.; Song, J.; Spieler, H. G.; Stalder, B.; Staniszewski, Z.; Stark, A. A.; Story, K.; Stubbs, C. W.; Suhada, R.; Van Engelen, A.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - 763:2(2013), pp. 147.147-147.-. [10.1088/0004-637X/763/2/147]
Cosmological constraints from sunyaev-zel'dovich-selected clusters with X-ray observations in the first 178 deg 2 of the south pole telescope survey
Saro, A.;
2013-01-01
Abstract
We use measurements from the South Pole Telescope (SPT) Sunyaev–Zel’dovich (SZ) cluster survey in combination with X-ray measurements to constrain cosmological parameters. We present a statistical method that fits for the scaling relations of the SZ and X-ray cluster observables with mass while jointly fitting for cosmology. The method is generalizable to multiple cluster observables, and self-consistently accounts for the effects of the cluster selection and uncertainties in cluster mass calibration on the derived cosmological constraints. We apply this method to a data set consisting of an SZ-selected catalog of 18 galaxy clusters at z > 0.3 from the first 178 deg2 of the 2500 deg2 SPT-SZ survey, with 14 clusters having X-ray observations from either Chandra or XMM-Newton. Assuming a spatially flat ΛCDM cosmological model, we find the SPT cluster sample constrains σ8(Ωm/0.25)0.30 = 0.785 ± 0.037. In combination with measurements of the cosmic microwave background (CMB) power spectrum from the SPT and the seven-year Wilkinson Microwave Anisotropy Probe data, the SPT cluster sample constrains σ8 = 0.795±0.016 and Ωm = 0.255±0.016, a factor of 1.5 improvement on each parameter over the CMB data alone. We consider several extensions beyond the ΛCDM model by including the following as free parameters: the dark energy equation of state (w), the sum of the neutrino masses (Σmν ), the effective number of relativistic species (Neff), and a primordial non-Gaussianity (fNL). We find that adding the SPT cluster data significantly improves the constraints on w and Σmν beyond those found when using measurements of the CMB, supernovae, baryon acoustic oscillations, and the Hubble constant. Considering each extension independently, we best constrain w = −0.973 ± 0.063 and the sum of neutrino masses Σmν < 0.28 eV at 95% confidence, a factor of 1.25 and 1.4 improvement, respectively, over the constraints without clusters. Assuming a ΛCDM model with a free Neff and Σmν , we measure Neff = 3.91 ± 0.42 and constrain Σmν < 0.63 eV at 95% confidence. We also use the SPT cluster sample to constrain fNL = −220±317, consistent with zero primordial non-Gaussianity. Finally, we discuss the current systematic limitations due to the cluster mass calibration, and future improvements for the recently completed 2500 deg2 SPT-SZ survey. The survey has detected ∼500 clusters with a median redshift of ∼0.5 and a median mass of ∼2.3 × 1014 M h−1 and, when combined with an improved cluster mass calibration and existing external cosmological data sets will significantly improve constraints on w.Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
