Comparison of the abundance of ejecta as a function of the mass for [Fe/H]=–1.2 and –1.5. The fiducial abundance regions for GS_3073 are the green strips, while the green dot-dashed line represents the lowest possible abundance for log(C/O). The evolving masses which best reproduce the fiducial abundances of the UV dense region close to the SMBH are ~4-3.5 M_⊙, for Z=0.001 and 4-3 M_⊙ for Z=0.002.