Age-dating luminous red galaxies observed with the Southern African Large Telescope
By A. Ratsimbazafy, S. I. Loubser, S. Crawford, C. Cress, Bruce A. Bassett, Robert Nichol, P. V. Nwu, Uwc, Saao, Chpc and 4 more. 2016
508 citations recorded by the source corpus.
We measure a value for the cosmic expansion of $H(z) = 89 \pm 23$(stat) $\pm$ 44(syst) km s$^{-1}$ Mpc$^{-1}$ at a redshift of $z \simeq 0.47$ based on the differential age technique. This technique, also known as cosmic chronometers, uses the age difference between two redshifts for a passively evolving population of galaxies to calculate the expansion rate of the Universe. Our measurement is based on analysis of high quality spectra of Luminous Red Galaxies (LRGs) obtained with the Southern African Large Telescope (SALT) in two narrow redshift ranges of $z \simeq 0.40$ and $z \simeq 0.55$ as part of an initial pilot study. Ages were estimated by fitting single stellar population models to the observed spectra. This measurement presents one of the best estimates of $H(z)$ via this method at $z\sim0.5$ to date.
Subfields: Astronomy and Astrophysics
View Paper: https://www.semanticscholar.org/paper/b0c7867426e4ef5f1b328231579aeaee979e0188
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In Astronomy and Astrophysics
Citations in the corpus
- Hubble Parameter and Baryon Acoustic Oscillation Measurement Constraints on the Hubble Constant, the Deviation from the Spatially Flat ΛCDM Model, the Deceleration–Acceleration Transition Redshift, and Spatial Curvature (2017, unknown): “Ratsimbazafy et al. (2017), (7).”
- Setting the Stage for Cosmic Chronometers. II. Impact of Stellar Population Synthesis Models Systematics and Full Covariance Matrix (2020, methodology): “…et al. 2005; Carson & Nichol 2010; Stern et al. 2010; Liu et al. 2012; Moresco et al. 2012b; Zhang et al. 2014; Moresco 2015; Moresco et al. 2016b; Ratsimbazafy et al. 2017), it was demonstrated how this method can be applied to galaxy surveys over a wide range of redshifts, 0.1 < z < 2, and that…”
- Toward a Better Understanding of Cosmic Chronometers: A New Measurement of H(z) at z ∼ 0.7 (2021, methodology): “The other available measurements are made analyzing the ages of luminous red galaxies with the full spectral fitting technique (using, in particular, the Ulyss code; Zhang et al. 2014; Ratsimbazafy et al. 2017).”