Distance To Galaxy Using Supernova - Essay Example

Type Ia supernova have proven to be excellent distance indicators when well treated. Although they have virtues that are linked to standard candle, they are not standard candle. Combined with the high luminosity of objects which make them detectable out of redshift near 1, they can be used to measure cosmological distances and provide determination of acceleration of the universe. The assumption that is made is that supernova expands in a spherical symmetric manner. It is unlikely that supernova Ia will provide genuine and detailed results of the peculiar velocity field just because it rarely occurred.

The astronomers realized that it was possible to measure apparent magnitude of supernova knowing what its absolute magnitude was. The measured distance was to be used to calculate the distance modulus. 1 square CCD array was used in taking the sample images for later analysis. The images were used to measure properties of the supernova (SN) host galaxies, such as total stellar mass, star formation rate or host galaxy redshift. Finally the apparent brightness and luminosity were combined with the aim of finding distance .

During every check-up for the supernova, the value for flux and epoch of the i band maximum,f1 and tpeak was estimated .The flux value of f g, fr and fz for the same epoch was estimated The SNLS result that was released for the first time consisted of photometry and red shift of 40 supernova 1.The result were having griz light curves with photometry covering the epoch of the maximum flux in the i band. The coefficients ci was derived using 20 SNe Ia and later confirmed by another 20SNe Ia.

The bias corrected mean and standard deviation of ci computed using the jack-knife technique and the result provided as given below The results obtained for the values of (Zphot -Zspec)/( Zphot +Zspec ) was plotted against the values of Z spec on a graph . This was done for 20 SN Ia and 40 SN Ia. The above calculated value fro