Cosmic dynamics in the era of Extremely Large Telescopes

By J. Liske, A. Grazian, E. Vanzella, M. Dessauges, M. Viel, L. Pasquini, M. Haehnelt, S. Cristiani, F. Pepe, G. Ávila and 17 more. 2008

229 citations recorded by the source corpus.

The redshifts of all cosmologically distant sources are expected to experience a small, systematic drift as a function of time due to the evolution of the Universe's expansion rate. A measurement of this effect would represent a direct and entirely model-independent determination of the expansion history of the Universe over a redshift range that is inaccessible to other methods. Here we investigate the impact of the next generation of Extremely Large Telescopes on the feasibility of detecting and characterising the cosmological redshift drift. We consider the Lyman alpha forest in the redshift range 2 < z < 5 and other absorption lines in the spectra of high redshift QSOs as the most suitable targets for a redshift drift experiment. Assuming photon-noise limited observations and using extensive Monte Carlo simulations we determine the accuracy to which the redshift drift can be measured from the Ly alpha forest as a function of signal-to-noise and redshift. Based on this relation and using the brightness and redshift distributions of known QSOs we find that a 42-m telescope is capable of unambiguously detecting the redshift drift over a period of ~20 yr using 4000 h of observing time. Such an experiment would provide independent evidence for the existence of dark energy without assuming spatial flatness, using any other cosmological constraints or making any other astrophysical assumption.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/452a600d7b3004dc54f0cdae1c9c884880b4c045

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In Astronomy and Astrophysics

Citations in the corpus

The Neutral Hydrogen Cosmological Mass Density at z = 5 (2015, methodology): “To address this we introduced line clustering, similar to that used by Liske et al. (2008) to model the Lyα forest at z ∼ 3.”
Holographic dark energy (2016, methodology): “According to the Monte Carlo simulations, the uncertainty of ∆v expected by the cosmic dynamics experiment can be expressed as [243]”
Observational probes of cosmic acceleration (2012, background): “…the CODEX spectrograph proposed for the European Extremely Large Telescope could measureH(z) over z = 2−5 with an aggregate precision of ≈ 2% (see Liske and Codex Team 2006 and Balbi and Quercellini 2007 for similar discussions and Liske et al. 2008 for detailed calculations of CODEX performance).”
The physics of the intergalactic medium (2007, background): “Even more ambitious would be the direct detection of the expansion of the Universe through the monitoring of absorption lines along fixed lines of sight over a period of several years through spectroscopy on extremely large telescopes (Corasaniti et al., 2007; Liske et al., 2008).”
High‐precision calibration of spectrographs (2010, background): “The cosmic acceleration of suitable objects (QSOs at redshifts below ∼5) is expected to be of the order of about 1 cm s−1 yr−1 (Liske et al. 2008), corresponding to a frequency shift of 20 kHz at a wavelength of 500 nm (600 THz).”