ANITA Summer School lecture notes [PDF]

Excel file of Z=0.020 stellar population predictions for colours and numbers [DOWNLOAD]

Tasks:

1) What fraction of mass must be ejected from a binary in a supernova for it to become unbound? (Consider gravitational binding energy and kinetic energy in the binary and express the result as a fraction of the total mass).

2) Using the above spread sheet for the two pages with UBVRIJHK colours compare how the magnitudes vary between the two and determine which is the single star and which is the binary. (Plot a few of the colours, blue and red, which have the bigger difference? Or try to plot a colour like V-I versus time).

3) Using the same spread sheet but now the "Numbers" pages estimate the ratio of the number of O to WR stars, the number of RSG to WR stars and the number of WC to WN+WNH stars assuming constant star-formation rate for 1 Gyr. Which is binary and which is single star population? (Pages have already had the total numbers calculated assuming constant star-formation so you do just have to divide the totals into each other).

Then compare these to the observed values for the Galaxy and galaxies of a similar metallicity of 0.1, 1.15 and 0.6. (The are latest numbers from observers!)

[If you have time, how do these ratios vary with the age of the stellar population?]