Synchrotron emission from a nearby zone of SgrA${}^{\ast }$

Quasi-linear diffusion (QLD), driven by the cyclotron instability, is proposed as a mechanism for the possible generation of synchrotron emission in the nearby zone of SgrA${}^{\ast }$. For physically reasonable parameters, the QLD, by causing non-zero pitch angle scattering lets electrons with the relativistic factors of the order of ${10}^8$ emit synchrotron radiation in the hard $X$-ray spectral band $\sim 120$ keV.