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Using quasars as standard clocks for measuring cosmological redshift.

De-Chang Dai1, Glenn D Starkman, Branislav Stojkovic

  • 1Astrophysics, Cosmology and Gravity Centre, University of Cape Town, Rondebosch, Private Bag, 7700, South Africa.

Physical Review Letters
|September 26, 2012
PubMed
Summary
This summary is machine-generated.

Researchers discovered new patterns in quasar light curves, suggesting quasars can act as standard clocks. This allows for reliable redshift determination using their light curve properties.

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Area of Science:

  • Astronomy and Astrophysics
  • Cosmology

Background:

  • Quasar light curves exhibit complex variability.
  • Understanding quasar behavior is crucial for cosmological studies.

Purpose of the Study:

  • To identify novel patterns in quasar light curves.
  • To explore the potential of using quasars as standard cosmological clocks.
  • To develop methods for determining quasar redshift from light curve data.

Main Methods:

  • Characterizing quasar light curve segments using linear fitting slopes.
  • Analyzing global time and flux shifts between quasar light curves.
  • Fitting redshift ratios to identify overlaps in light curves.

Main Results:

  • Identified a direct relationship between light curve slopes and quasar redshifts.
  • Demonstrated significant overlaps between different quasar light curves by fitting redshift ratios.
  • Successfully determined the redshift of one quasar from another's light curve.

Conclusions:

  • Quasar light curve patterns offer a new method for redshift determination.
  • Quasars can be utilized as reliable standard clocks in cosmological measurements.
  • Two independent methods were developed to find quasar redshift from light curve analysis.