Extreme gas properties in the most distant quasars
Extreme gas properties in the most distant quasars
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DOI：
10.1051/0004-6361:20035704
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发表时间：
2003-12
影响因子：
6.5
通讯作者：
R. Maiolino;E. Oliva;F. Ghinassi;M. Pedani;F. Mannucci;R. Mújica;Y. Juarez
中科院分区：
文献类型：
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作者：
R. Maiolino;E. Oliva;F. Ghinassi;M. Pedani;F. Mannucci;R. Mújica;Y. Juarez
我们提供了八个已知最遥远的类星体的近红外低分辨率光谱，红移范围为4.9 < z < 6.4。这些类星体中有一半具有深、宽和蓝移的吸收特征，与高和低电离物质（CIV、SiIV、Al III、Mg II）有关，即它们属于宽吸收线类星体（BAL），与致密气体的强大流出有关。虽然样本很小，但BAL类星体的大部分，吸收特征的深度和电离状态表明，这些最遥远的类星体比低红移（z < 4）类星体被大量的致密气体包围。讨论了极高的吸积率和与类星体及其宿主星系早期形成的关联方面的可能解释。尘埃的吸收特性，与气体沿着视线，出现不同的相对于较低的红移类星体，可能表明不同的尘埃物理在这些最高的红移。
We present near-IR, low resolution spectra of eight of the most distant quasars known, with redshifts in the range 4.9 < z < 6.4. Half of these quasars are characterized by deep, broad and blueshifted absorption features associated with both high and low ionization species (CIV, SiIV, AlIII, MgII), i.e. they belong to the class of Broad Absorption Line (BAL) quasars, which are associated with powerful outflows of dense gas. Although the sample is small, the large fraction of BAL quasars, the depth and ionization state of the absorption features suggest that these most distant quasars are surrounded by a much larger amount of dense gas than lower redshift (z < 4) quasars. The possible interpretation in terms of extremely high accretion rates and the association with the early formation of quasars and of their host galaxies is discussed. The absorption properties of the dust, associated with the gas along the line of sight, appear different with respect to lower redshift quasars, possibly indicating different dust physics at these highest redshifts.