Time Dilation and Quasar Variability

@article{Hawkins2001TimeDA,
  title={Time Dilation and Quasar Variability},
  author={Michael R. S. Hawkins},
  journal={The Astrophysical Journal},
  year={2001},
  volume={553}
}
  • M. Hawkins
  • Published 4 May 2001
  • Physics
  • The Astrophysical Journal
The timescale of quasar variability is widely expected to show the effects of time dilation. In this Letter, we analyze the Fourier power spectra of a large sample of quasar light curves to look for such an effect. We find that the timescale of quasar variation does not increase with redshift, as required by time dilation. Possible explanations of this result all conflict with widely held consensus in the scientific community. 
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References

SHOWING 1-10 OF 10 REFERENCES
Quasar Variability and Gravitational Microlensing
In this Letter we examine the claim by Baganoff & Malkan that the timescale of brightness variations of quasars increases with decreasing optical wavelength, and that this effect can offset a time…
The variability of optically selected quasars
The variability properties of a sample of 300 optically selected quasars near the South Galactic Pole (SGP) have been studied over a baseline of 16 years using a series of twelve UK Schmidt Telescope…
Time Dilation in the Light Curve of the Distant Type Ia Supernova SN 1995K
The light curve of a distant Type Ia supernova acts like a clock that can be used to test the expansion of the universe. SN 1995K, at a spectroscopic redshift of z = 0.479, provides one of the first…
Steps toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. XV. Long-Term Optical Monitoring of NGC 5548
We present the results of 3 yr of ground-based observations of the Seyfert 1 galaxy NGC 5548, which, combined with previously reported data, yield optical continuum and broad-line Hβ light curves for…
Time Dilation in the Peak-to-Peak Timescales of Gamma-Ray Bursts
We present strong evidence of time stretching in the peak-to-peak timescales in the light curves of BATSE gamma-ray bursts (GRBs). Extensive tests are performed on artificially dilated bursts to…
Optical variability in active galactic nuclei: starbursts or disk instabilities?
Aperiodic optical variability is a common property of active galactic nuclei (AGNs), though its physical origin is still open to question. To study the origin of the optical-ultraviolet variability…
Time Dilation from Spectral Feature Age Measurements of Type Ia Supernovae
We have developed a quantitative, empirical method for estimating the age of Type Ia supernovae (SNe Ia) from a single spectral epoch. The technique examines the goodness of fit of spectral features…
The Late-Time Emission of Thermonuclear Supernovae
A number of questions raised during this meeting can be clarified by the study of the emission of SNe Ia at late times. Do WDs explode below the Chandrasekhar mass? Or, on the contrary, are the…
A Robust determination of the time delay in 0957+561a,b and a measurement of the global value of Hubble's constant
Continued photometric monitoring of the gravitational lens system 0957+561A, B in the g and r bands with the Apache Point Observatory (APO) 3.5 m telescope during 1996 shows a sharp g-band event in…
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