Question

In: Physics

Assume that there was a starburst that produced 1011 solar masses of stars with a minimum...

Assume that there was a starburst that produced 1011 solar masses of stars with a minimum mass of 0.3 solar masses and a maximum mass of 100 solar masses. The number of stars as a function of mass is N(M) = KM-2.35, where K is a normalization constant. The current turnoff mass of the population is 1 solar mass

  1. Compute the number of stars and the total mass of stars that are still on the main sequence.
  2. Assume that all stars with masses between 1 and 8 solar masses became white dwarfs. Compute the total number of white dwarfs in this population

Solutions

Expert Solution

If N(M) gives the number of stars with mass M then M*N(M) will give the total mass of stars with mass M each

If we sum M*N(M) over all possible masses, we shall get the total mass of the starburst which is 1011 solar masses.

If we do integration, we get inconsistent results. Therefore we will do it numerically.

We assume that N(M) gives the number of stars within the mass range M and M + dM (where dM is small compared to M)

then for a given value of dM, we sum M*N(M) for all possible values of M

It appears that in this way K will depend on dM. It does but we will see that the ratio K/dM approaches a constant value and so do the total number of stars still in the main sequence and total number of white dwarfs

python code:

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