Hostname: page-component-7c8c6479df-ph5wq Total loading time: 0 Render date: 2024-03-28T10:52:40.453Z Has data issue: false hasContentIssue false

Studying Luminous Red Galaxies to probe H(z) at high redshift

Published online by Cambridge University Press:  17 July 2013

A. Ratsimbazafy
Affiliation:
Physics Dept, University of the Western Cape, Private Bag X17. Cape Town 7535, South Africa email: raljha.a@gmail.com
C. Cress
Affiliation:
Physics Dept, University of the Western Cape, Private Bag X17. Cape Town 7535, South Africa email: raljha.a@gmail.com Centre of High Performance Computing, 15 Lower Hope St. Cape Town 7700, South Africa
S. Crawford
Affiliation:
South African Astronomical Observatory, PO box 9. Cape Town 7935, South Africa
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Luminous Red Galaxies (LRGs) have old, red stellar populations often interpreted as evidence of a formation scenario in which these galaxies form in a single intense burst of star formation at high redshift. By measuring the average age of LRGs at two different redshifts, one can potentially measure the redshift interval corresponding to a time interval and thus measure the Hubble parameter H(z) ≈ −(1 + z)−1 Δ zt (as in Jimenez & Loeb). The goal of this project is to measure directly the expansion rate of the universe at the redshift range 0.1 < z < 1.0 within 3% precision. We explore the age-dating of Sloan Digital Sky Survey LRGs using the stellar population models of Lick absorption line indices after stacking spectra in redshift bins to increase the signal-to-noise. We also use the method of full spectral fitting to measure the ages of LRGs observed with the Southern Africa Large Telescope (SALT).

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2013 

References

Crawford, S., Ratsimbazafy, A., Cress, C., et al. 2010, MNRAS, 406, 2569Google Scholar
Jimenez, & Loeb, 2002, ApJ, 573, 37CrossRefGoogle Scholar