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
Type Ia supernovae


Basic Idea: Type Ia SN as standard candle, use to test kinematic effects of lambda, ie distance/redshift relation.

Systems of interest: Type Ia SN

  • What they are (believed to be): pictures
  • Usefulness as standard candle

Observations

  • Searching Method
  • Standard Candle:
    • light curve fitting
    • spectral evolution

Current Results

Criticisms and current questions

  • What are they? What is light curve relation?
    theorists at work on this
  • Evolution--rise time question
    want and are getting more
  • Low redshift sample
    getting more
  • dust: not much seen, also grey dust?
    going to higher z

Current work

  • As mentioned above--get more SN: high z and low z
  • Cepheids to calibrate (very low number)
  • Characterize better (all in a night's work)
  • Many groups

Future plans and hopes with this method

  • Better systematics
  • satellite (SNAPsat)

Other cosmological tests these can be used for

Some References


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


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