Time Variability of Quasars: the Structure Function Variance

  title={Time Variability of Quasars: the Structure Function Variance},
  author={Chelsea MacLeod and Željko Ivezi{\'c} and Willem Hendrik de Vries and Branimir Sesar and Andrew C. Becker},
  journal={arXiv: Astrophysics},
Significant progress in the description of quasar variability has been recently made by employing SDSS and POSS data. Common to most studies is a fundamental assumption that photometric observations at two epochs for a large number of quasars will reveal the same statistical properties as well‐sampled light curves for individual objects. We critically test this assumption using light curves for a sample of ∼2,600 spectroscopically confirmed quasars observed about 50 times on average over 8… 

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Astrophys. J
  • Astrophys. J
  • 1998
Ivezi´Ivezi´c, and 14 co-authors
  • Astron. J
  • 2006
co-autho rs,Astron
  • J., 122,
  • 2001
Kron, and 11 co-authors
  • Astrophys. J
  • 2004
Ivezíc, and 14 co-authors
  • Astron. J.,
  • 2006
Astron. J
  • Astron. J
  • 2007
Astron. J
  • Astron. J
  • 2007