Noterdaeme, P. ; Petitjean, P. ; Srianand, R. ; Ledoux, C. ; Lopez, S. (2011) The evolution of the cosmic microwave background temperature. Measurements of TCMB at high redshift from carbon monoxide excitation Astronomy and Astrophysics, 526 (L7). L7.1-L7.4. ISSN 0004-6361
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Official URL: http://www.aanda.org/articles/aa/abs/2011/02/aa161...
Related URL: http://dx.doi.org/10.1051/0004-6361/201016140
Abstract
A milestone of modern cosmology was the prediction and serendipitous discovery of the cosmic microwave background (CMB), the radiation leftover after decoupling from matter in the early evolutionary stages of the Universe. A prediction of the standard hot Big-Bang model is the linear increase with redshift of the black-body temperature of the CMB (TCMB). This radiation excites the rotational levels of some interstellar molecules, including carbon monoxide (CO), which can serve as cosmic thermometers. Using three new and two previously reported CO absorption-line systems detected in quasar spectra during a systematic survey carried out using VLT/UVES, we constrain the evolution of TCMB to z ∼ 3. Combining our precise measurements with previous constraints, we obtain TCMB(z) = (2.725 ± 0.002) × (1 + z)1-β K with β = -0.007 ± 0.027, a more than two-fold improvement in precision. The measurements are consistent with the standard (i.e. adiabatic, β = 0) Big-Bang model and provide a strong constraint on the effective equation of state of decaying dark energy (i.e. weff = -0.996 ± 0.025).
Item Type: | Article |
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Source: | Copyright of this article belongs to EDP Sciences. |
Keywords: | Cosmology: Observations; Cosmic background radiation; Quasars; Absorption lines |
ID Code: | 55292 |
Deposited On: | 18 Aug 2011 08:19 |
Last Modified: | 18 May 2016 07:37 |
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