Low-angular-momentum accretion shocks can power weak-to-moderate X-ray flares from SgrA*

X-ray flares from Sgr A* span broad ranges in duration, fluence, and luminosity, but their origin remains unsettled. We test whether standing shocks in low-angular-momentum magnetized accretion flows can provide a viable energy reservoir to account for these events. Using semi-analytic trans-magnetosonic shock solutions, we estimate the kinetic energy available in the downstream post-shock flow and compare it with the 25-year Chandra X-ray flare catalog. For each theoretical solution, we compute the required efficiency ε=E data/E sh, where E data is the observed radiated energy for each flare and E sh is the available energy in the shocked flow. Notably, the weak flares require ε about10-3 -- 10-2, while moderate flares require a few percent. We perform the analyses for weakly and highly spinning cases, and the resulting weak-to-moderate flare energy budget remains unchanged. For the fiducial accretion rate and bolometric correction, the kinetic energy reservoir in standing shock is sufficient for the observed weak-to-moderate flare population, whereas the strongest events likely require higher efficiency which can be mediated via additional magnetic energy dissipation channel.