Cosine and sine Fourier transform of $e^{-\sqrt{x/a}}$

Question

I would like to calculate the cosine and sine Fourier transform of $e^{-\sqrt{x/a}}$, i.e.

$$\int_0^{\infty}\,e^{-\sqrt{x/a}}\cos(kx)\,dx$$

and

$$\int_0^{\infty}\,e^{-\sqrt{x/a}}\sin(kx)\,dx$$

Any suggestion on where to start?