| 类星体SDSSJ0916+2921的类银河系2175A 尘埃消光特征 |
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| 引用本文： | 时雪草,潘翔,窦立明,王建国,姜鹏,杨臣威,周宏岩.类星体SDSSJ0916+2921的类银河系2175A 尘埃消光特征[J].天文学报,2020,61(2):15. |
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| 作者姓名： | 时雪草 潘翔 窦立明 王建国 姜鹏 杨臣威 周宏岩 |
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| 作者单位： | 中国科学技术大学天文学系合肥230026,中国极地研究中心上海200136,广州大学天体物理中心广州510006,中国科学院云南天文台昆明650216,中国极地研究中心上海200136,中国极地研究中心上海200136,中国科学技术大学天文学系合肥230026;中国极地研究中心上海200136 |
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| 基金项目： | 国家自然科学基金项目(11903029、11973037)资助 |
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| 摘 要： | 光谱观测显示类星体SDSS J091613.60+292106.1 (简称J0916+2921, 系统红移zem=1.1418\pm 0.0018)中有特殊的2175A尘埃消光特征, 其强度显著大于银河系平均强度. 光谱同时探测到与尘埃成协的丰富气体吸收线, 确定吸收线系统红移为zbs = 1.1413 \pm 0.0002, 和类星体红移一致. 气态金属离子柱密度相对太阳丰度的比例为Al/Zn =-1.68 \pm 0.10, Cr/Zn=-0.49 \pm0.10, Fe/Zn = -0.81 pm 0.18. 尘埃耗散作用显著, 说明该系统中尘埃十分丰富, 与观测的强尘埃消光特征吻合. 类银河系的2175A尘埃消光特征在类星体光谱中多见于中间插入吸收线系统, 至今未明确认证内禀吸收线系统出现该特征, 类星体SDSS J0916+2921是目前仅有的数个候选者之一. 该类星体X射线辐射相较一般类星体更强, 后续可用作研究2175A}尘埃在强高能射线照射条件下的形成与离解平衡, 以揭示2175A尘埃的化学成分、物理性质和起源.
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| 关 键 词： | 星系: 活动星系核 星际介质: 消光 类星体: 吸收线 |
| 收稿时间： | 2019/7/22 0:00:00 |
Milky-Way-Like 2175 A Dust Extinction Feature Observed toward the Quasar SDSS J0916+2921 |
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| SHI Xue-cao,PAN Xiang,DOU Li-ming,WANG Jian-guo,JIANG Peng,YANG Chen-wei and ZHOU Hong-yan.Milky-Way-Like 2175 A Dust Extinction Feature Observed toward the Quasar SDSS J0916+2921[J].Acta Astronomica Sinica,2020,61(2):15. |
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| Authors: | SHI Xue-cao PAN Xiang DOU Li-ming WANG Jian-guo JIANG Peng YANG Chen-wei and ZHOU Hong-yan |
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| Affiliation: | Department of Astronomy, University of Science and Technology of China, Hefei 230026,Polar Research Institute of China, Shanghai 200136,Center for Astrophysics, Guangzhou University, Guangzhou 510006,Yunnan Observatories, Chinese Academy of Sciences, Kunming 650216,Polar Research Institute of China, Shanghai 200136,Polar Research Institute of China, Shanghai 200136 and Department of Astronomy, University of Science and Technology of China, Hefei 230026;Polar Research Institute of China, Shanghai 200136 |
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| Abstract: | We report a Milky--Way--like 2715 A dust extinction feature observed toward the quasar SDSS J091613.60+292106.1 (J0916+2921) (system redshift zem=1.1418\pm 0.0018) spectroscopically, whose strength is greater than the average Galactic value obviously. Plenty of metal absorption lines were detected at a redshift of zab = 1.1413\pm 0.0002, which is associated with the quasar emissions. The ratios of column densities of gaseous metal ions relative to Solar metallicities are Al/Zn] = -1.68\pm 0.10, Cr/Zn] = -0.49\pm 0.10, and Fe/Zn = -0.81\pm 0.18,showing significant dust depletions. The pattern indicates that the absorber is heavily dusty,supporting the detection of 2175A dust extinction feature. The Milky--Way--like dust extinction was usually observed in the intervening quasar absorbers, but its existence in the quasar intrinsic absorbers has never been confirmed. The associated dusty absorber toward the quasar SDSS J0916+2921 is on of the several intrinsic2175Aabsorber candidates. The X--ray radiation of the quasar is greater than the average value. This might provide a natural laboratory for further studying the equilibrium of formation and destruction of 2175Adust grains in the harsh radiation field, so that their chemical compositions, physical structures, and origins are revealed. |
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| Keywords: | galaxies: active galactic nucleus (AGN) ISM: extinction quasars: absorption lines |
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