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)^(λ2796)≥3σ_(w)and W_(r...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)^(λ2796)≥3σ_(w)and W_(r)^(λ2803)≥2σ_(w)in a redshift range of 0.4554≤z_(abs)≤2.1110.For quasars observed by both LAMOST and SDSS,we find that 135 Mg_(Ⅱ)NALs were obviously observed in the LAMOST spectra,347 Mg_(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 11 NALs obviously observed in SDSS or LAMOST spectra,eight Mg 11 NALs were significantly changed with|ΔW_(r)^(λ2796)|≥3σw in time intervals ofΔMJD/(1+z_(em))=359-2819 d.展开更多
基金supported by the Guangxi Natural Science Foundation(2018GXNSFAA050001,2019GXNSFFA245008,GKAD19245136)the Scientific Research Project of Guangxi University for Nationalities(2018KJQD01)the National Natural Science Foundation of China(Grant Nos.11763001,11363001,12073007)。
文摘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)^(λ2796)≥3σ_(w)and W_(r)^(λ2803)≥2σ_(w)in a redshift range of 0.4554≤z_(abs)≤2.1110.For quasars observed by both LAMOST and SDSS,we find that 135 Mg_(Ⅱ)NALs were obviously observed in the LAMOST spectra,347 Mg_(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 11 NALs obviously observed in SDSS or LAMOST spectra,eight Mg 11 NALs were significantly changed with|ΔW_(r)^(λ2796)|≥3σw in time intervals ofΔMJD/(1+z_(em))=359-2819 d.
