  The ground state of the proton-rich nucleus 23Al has been studied by
one-proton removal on a carbon target at about 50 MeV/nucleon using the EXOGAM
+ SPEG experimental setup at GANIL. Longitudinal momentum distributions of the
22Mg breakup fragments, inclusive and in coincidence with gamma rays
de-exciting the residues, were measured. The ground-state structure of 23Al is
found to be a configuration mixing of a d-orbital valence proton coupled to
four core states - 0$^{+}_{gs}$, 2$^{+}_{1}$, 4$^{+}_{1}$, 4$^{+}_{2}$. We
confirm the ground state spin and parity of 23Al as $J^{\pi} = 5/2^{+}$. The
measured exclusive momentum distributions are compared with extended Glauber
model calculations to extract spectroscopic factors and asymptotic
normalization coefficients (ANCs). The spectroscopic factors are presented in
comparison with those obtained from large-scale shell model calculations. We
determined the asymptotic normalization coefficient of the nuclear system
$^{23}$Al$_{gs}$ $\rightarrow$ $^{22}$Mg(0$^{+}$) + p to be
$C^{2}_{d_{5/2}}$($^{23}Al_{gs}$) = (3.90 $\pm$ 0.44) $\times$ 10$^{3}$
fm$^{-1}$, and used it to infer the stellar reaction rate of the direct
radiative proton capture $^{22}$Mg(p,$\gamma$)$^{23}$Al. Astrophysical
implications related to $^{22}$Na nucleosynthesis in ONe novae and the use of
one-nucleon breakup at intermediate energies as an indirect method in nuclear
astrophysics are discussed.
