Harvard University Department of Astronomy

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 Syllabus References Lecture References Useful Links Contact Info