摘要
天球上靠近的两个高红移类星体(也称为背景类星体)与低红移类星体(也称为前景类星体)组成一对类星体对.本文利用斯隆数字巡天光谱数据,获得22对类星体对,其前景类星体的径向方向(视线方向)和横向方向(垂直视线方向)都探测到成协的MgⅡλλ2796;2803吸收线,其中,横向方向的吸收线通过背景类星体光谱探测,径向方向的吸收线通过前景类星体光谱探测.这22对类星体对在前景类星体处的投影距离范围是101.7-473.9 kpc.研究发现,前景类星体横向方向的MgⅡλλ2796;2803吸收线由前景类星体宿主星系晕的吸收介质主导,但是径向方向的吸收线可能起源于类星体外流、宿主星系以及宿主星系晕.如果径向方向的吸收线起源于类星体宿主星系或宿主星系晕,其吸收线强度、宽度和相对类星体中心的视向速度都与横向方向的吸收线类似.但是,如果径向方向的吸收线起源于类星体外流,其吸收线强度、宽度和相对类星体中心的视向速度在较高概率上都可能与横向方向的吸收线不同.
Two quasars close in the celestial sphere but with evidently distinct systemic redshifts constitute a quasar pair.Using the quasar spectra gathered by the Sloan Digital Sky Survey,this research obtained 22 quasar pairs,where the associated MgⅡλλ2796;2803 absorption lines at a close systemic redshift are identified along the transverse direction toward the background quasar and the radial direction toward the foreground quasar for each of the pairs.In the transverse direction,we observe that the MgⅡλλ2796;2803 detected would be dominated by the halos of foreground quasars,while the MgⅡλλ2796;2803 detected in the radial direction can be originated in quasar outflows,host galaxies,and halos.If the absorption lines originated in quasar host galaxies or halos,the relative velocities along the sightline and the strengths and widths of the absorption lines detected in the radial direction are consistent with those detected in the transverse direction.However,all the relative velocities along the sightline and the strengths and widths of the outflow absorption lines detected in the radial directions are likely different from those detected in the transverse directions.
作者
陈哲耕
陈志福
王志文
庞婷婷
CHEN ZheGeng;CHEN ZhiFu;WANG ZhiWen;PANG TingTing(School of Mathematics and Physics,Guangxi Minzu University,Nanning 530006,China)
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2023年第5期177-185,共9页
Scientia Sinica Physica,Mechanica & Astronomica
基金
广西自然科学基金(编号:桂科AD19245136,2019GXNSFFA245008)
国家自然科学基金(编号:12073007)
广西民族大学科学研究计划(编号:2018KJQD01)
广西壮族自治区大学生创新创业项目(编号:202010608056)资助。
关键词
类星体
吸收线
横向
径向
quasars
absorption lines
transverse direction
radial direction
