The Mg Ii Absorption Line Systems In Quasar Spectra From The Large Sky Area Multi-Object Fiber Spectroscopic Telescope

Making use of quasar spectra from LAMOST, in the spectral data around the Mg II emission lines, research described in this paper has detected 217 Mg II narrow absorption lines (NALs) with W-r(lambda 2796) >= 3 sigma(w) and W-r(lambda 2803) >= 2 sigma(w) in a redshift range of 0.4554 <= z(abs) <= 2.1110. For quasars observed by both LAMOST and SDSS, we find that 135Mg II NALs were obviously observed in the LAMOST spectra, 347Mg II NALs were were apparent in the SDSS spectra, and 132 Mg II NALs were clearly present in both the SDSS and LAMOST spectra. The missed Mg II NALs are likely ascribed to low signal-to-noise ratios of corresponding spectra. Among the Mg II NALs obviously observed in SDSS or LAMOST spectra, eight Mg II NALs were significantly changed with vertical bar Delta W-r(lambda 2796)vertical bar >= 3 sigma(w) in time intervals of Delta MJD/(1 + z(em)) = 359 - 2819 d.