Gravitational wave background spectra from cosmic strings

The file spectrum.dat gives the expected gravitational wave stochastic background spectrum due to Abelian-Higgs cosmic strings, as discussed in "Stochastic gravitational wave background from smoothed cosmic string loops" and "New limits on cosmic strings from gravitational wave observation". The columns are

1. Negative base 10 logarithm of Gμ, running from 8.0 to 25.0 in steps of 0.25
2. Frequency f, running from 10^-15 to 10¹⁰ with logarithmic spacing 10^0.01
3. Resulting value of h² Ω(ln f)