Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-07-02
Astronomy and Astrophysics
Astrophysics
4+epsilon pages, 4 Figures, accepted version
Scientific paper
10.1051/0004-6361:20078200
The recombination history of the Universe depends exponentially on the temperature, T_0, of the cosmic microwave background. Therefore tiny changes of T_0 are expected to lead to significant changes in the free electron fraction. Here we show that even the current 1sigma-uncertainty in the value of T_0 results in more than half a percent ambiguity in the ionization history, and more than 0.1% uncertainty in the TT and EE power spectra at small angular scales. We discuss how the value of T_0 affects the highly redshifted cosmological hydrogen recombination spectrum and demonstrate that T_0 could, in principle, be measured by looking at the low frequency distortions of the cosmic microwave background spectrum. For this no absolute measurements are necessary, but sensitivities on the level of ~30nK are required to extract the quasi-periodic frequency-dependent signal with typical Delta nu/nu~0.1 coming from cosmological recombination. We also briefly mention the possibility of obtaining additional information on the specific entropy of the Universe, and other cosmological parameters.
Chluba Jens
Sunyaev Rashid A.
No associations
LandOfFree
Is there a need and another way to measure the Cosmic Microwave Background temperature more accurately? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Is there a need and another way to measure the Cosmic Microwave Background temperature more accurately?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Is there a need and another way to measure the Cosmic Microwave Background temperature more accurately? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-692656