9.7在z=0.52时阻尼莱曼-α吸收体中的微米硅酸盐吸收
9.7 micrometer Silicate Absorption in a Damped Lyman-alpha Absorber at z=0.52
摘要：
我们报告了使用斯皮策太空望远镜上的红外光谱仪（IRS）在z_{abs} = 0.524处对AO 0235 +164的阻尼莱曼α（DLA）系统中探测到的9.7微米硅酸盐吸收特征。该特征在吸收体静止框架中示出了超过约8-12微米的宽的浅轮廓，并且在等效宽度上似乎> 15 σ显著。实验室无定形橄榄石或弥漫的银河系星际云的硅酸盐吸收配置文件的功能是合理的。据我们所知，这是DLA中9.7微米硅酸盐吸收的第一个迹象。我们讨论了这一发现对类星体吸收体中尘埃性质的潜在影响。虽然该特征相对较浅（tau_{9.7} = 0.08-0.09），但它比从弥漫银河系星际云已知的tau_{9.7}与E（B-V）关系外推所预期的要深2倍。对类星体吸收器中9.7微米硅酸盐特征的进一步研究将为遥远星系中的尘埃打开一扇新的窗户。
英文摘要：
We report a detection of the 9.7 micrometer silicate absorption feature in a damped Lyman-alpha (DLA) system at z_{abs} = 0.524 toward AO0235+164, using the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope. The feature shows a broad shallow profile over about 8-12 micrometers in the absorber rest frame and appears to be > 15 sigma significant in equivalent width. The feature is fit reasonably well by the silicate absorption profiles for laboratory amorphous olivine or diffuse Galactic interstellar clouds. To our knowledge, this is the first indication of 9.7 micrometer silicate absorption in a DLA. We discuss potential implications of this finding for the nature of the dust in quasar absorbers. Although the feature is relatively shallow (tau_{9.7} = 0.08-0.09), it is about 2 times deeper than expected from extrapolation of the tau_{9.7} vs. E(B-V) relation known for diffuse Galactic interstellar clouds. Further studies of the 9.7 micrometer silicate feature in quasar absorbers will open a new window on the dust in distant galaxies.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
