引力透镜类星体SDSS J1004+4112的吸收线研究

Research of the Absorption Lines of GravitationalLensing Quasar SDSS J1004+4112

基于SDSS (Sloan Digital Sky Survey,斯隆数字巡天) DR15 (The Data Release 15,第15期数据)的光谱,分析引力透镜类星体SDSS J1004+4112两个像(A和B像之间的角距离约为3.73′′)的光谱。通过C IVλλ1548?, 1551?和Mg Ⅱλλ2796?, 2803?吸收双线,在A、B两个像的光谱上证认得到两个C IV吸收线系统和两个Mg Ⅱ吸收线系统。在引力透镜类星体SDSS J1004+4112 A, B两个像的光谱上C Ⅳ吸收线系统没有明显的差异(吸收线等值宽度差异的置信水平N△W<3),吸收体在视线方向上的横向尺度Dtra≈127.5 pc,相对类星体的速度βs<0.06,两视线上的吸收体可能是来源于类星体同一区域的本征吸收体。但是,两个Mg Ⅱ吸收线系统在两个像光谱上存在明显的差异(N△W> 3);A像光谱上只存在红移为0.831 1±0.000 3的Mg Ⅱ吸收线系统,吸收体的Dtra≈21.319 kpc;而B像光谱上只存在系统红移为0.671 1±0.006 1的Mg Ⅱ吸收线,吸收体的Dtra≈26.280 kpc。

Based on Data Release 15(DR15) of Sloan Digital Sky Survey(SDSS) published data, we analyzed the spectra of the two images of gravitational lensing Quasar SDSS J1004+4112 in the SQLS(SDSS Quasar Lens Search). The redshift of quasar is 1.734±0.002.We recognize two C IV and two Mg Ⅱ narrow absorption systems in the spectra of two images. The C Ⅳ absorption systems are alike in the spectra of the two images, but the two Mg Ⅱ absorption systems are very different. The Mg Ⅱ absorption system with redshift of 0.831 1±0.000 3 only exist in spectrum of A image, while another Mg Ⅱ absorption system with redshift of 0.671 1±0.006 1 only exist in B image. If they exist in the both images, their physical separations in the transverse direction(Dtra) are 21.319 and 26.280 kpc, respectively.We thought that the differences of Mg Ⅱ absorption systems are probably from the different absorbers in the two images of SDSS J1004+4112, and the sizes of these absorbers may be smaller than Dtra. The velocity of Mg Ⅱ absorber with redshift of 0.671 1±0.006 1 relative to lens is |βl|<0.02, therefore the absorber maybe root in the intrinsic absorber of lens galaxy. In addition, the Mg Ⅱ absorber with redshift of 0.831 1±0.000 3 maybe come from other interstellar medium or intergalactic medium, because | βl|>0.02 and βs>0.06.