Site Map
Follow us on Facebook Follow us on Twitter YouTube channel
Centro de Astrofísica da Universidade do Porto

Constraining the evolution of the CMB temperature with SZ measurements from Planck data

G. Luzzi, R. T. Génova-Santos, C. J. A. P. Martins, M. de Petris, L Lamagna

The CMB temperature-redshift relation, TCMB(z)=T0(1+z), is a key prediction of the standard cosmology but is violated in many non-standard models. Constraining possible deviations from this law is an effective way to test the ΛCDM paradigm and to search for hints of new physics. We have determined TCMB(z), with a precision up to 3%, for a subsample (103 clusters) of the Planck SZ cluster catalog, at redshifts in the range 0.01–0.94, using measurements of the spectrum of the Sunyaev-Zel'dovich (SZ) effect obtained from Planck temperature maps at frequencies from 70 to 353 GHz. The method adopted to provide individual determinations of TCMB(z) at cluster redshift relies on the use of SZ intensity change, Δ ISZ(ν) at different frequencies and on a Monte Carlo Markov chain approach. By applying this method to the sample of 103 clusters, we limit possible deviations of the form TCMB(z)=T0(1+z)1−β to be β= 0.012 ± 0.016, at 1σ uncertainty, consistent with the prediction of the standard model. Combining these measurements with previously published results, we get β=0.013±0.011.

Journal of Cosmology and Astroparticle Physics
Volume 09, Page 011
September 2015

>> PDF>> ADS>> DOI

Institute of Astrophysics and Space Sciences

Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.

Proceed on CAUP's website|Go to IA website