Harvard shield Harvard University Department of Astronomy
[red bar] [CfA Home]  [CfA Search]  [CfA Help]
[HU AST navigation bar] [HU AST Home]  [HU AST Search]  [HU AST Contact]

The Cosmological Constant
Alcock-Paczynski Test

Basic Idea: Ratio of observed angular size to radial/redshift size varies with cosmology. Find something which is known to be isotropic (i.e. where where transverse and radial intrinsic size are the same). Fixing the ratio of the intrinsic radial and transverse distances gives a relation between the measured radial and transverse distances depending on cosmological parameters.
  • ratio of these quantities analytically
  • dependence on redshift
  • standard ruler/sphere: correlation function

Systems of interest:

  1. galaxies
    • What one measures about them
    • observations
      redshift space distortions and other limitations
    • current and proposed projects
      deep, sdss, aa2df

  2. quasars
    • What they are (believed to be)
    • High redshift advantage
    • Upcoming observations

  3. Lyman-alpha forest
    • What it is (believed to be)
      early idea
      current paradigm
    • What one measures
      simple relation between density and optical depth
    • application of A-P with qso pairs
    • upcoming observations

Other cosmological tests and questions these systems are used for

  • sdss, aa2df
  • deep
  • Lyman alpha forest

    Some References

Home vertical line Syllabus vertical line References vertical line Lecture References vertical line Useful Links vertical line Contact Info

Back to Harvard University Department of Astronomy Academics.
Back to Harvard University Department of Astronomy Courses.

Comments or Questions? Contact jcohn@astron.berkeley.edu