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arXiv 0705.4365astro-ph
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4C 37.43扩展发射线区的积分场谱

Integral Field Spectroscopy of the Extended Emission-Line Region of 4C 37.43

Hai Fu, Alan Stockton

备注：
Accepted by ApJ. 13 pages including 6 figures and 3 tables
发表信息：
Astrophys.J.666:794-805,2007
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摘要：

我们提出了双子积分场光谱和凯克II长缝光谱的扩展发射线区域（EELR）周围的类星体4C 37.43。电离气体的速度结构是复杂的，不能用一个简单的动力学模型来解释。来自云的光谱与激波或“激波+散射体”电离模型不一致，但它们与类星体核的光电离一致。最佳拟合的光电离模型需要一种低金属丰度（12+log（O/H）< 8.7）的两相介质，该介质由填充因子为1（N ~ 1 \cc，T ~ 15000 K）的物质边界扩散组分组成，其中嵌入了小而致密的云（N ~ 400 \cc，T ~ 10^4 K）。高密度云是短暂的，可以通过低速激波（V_S \lesssim 100 \kms）压缩扩散介质而再生。我们的光电离模型给出了电离气体的总质量约为3 × 10 ^{10} M_sun，由该质量和观测到的速度场所隐含的总动能约为2 × 10 ^{58}尔格。发光的EELR仅限于陡谱射电噪类星体，但没有显示出与射电喷流的形态对应，这一事实表明，产生4C 37.43 EELR的驱动力是由喷流产生的大致球形冲击波。这种机制似乎能够喷射出与银河系总星际介质相当的质量，这表明“类星体模式”反馈可能确实是调节早期宇宙中恒星形成的有效手段。

英文摘要：

We present Gemini integral field spectroscopy and Keck II longslit spectroscopy of the extended emission-line region (EELR) around the quasar 4C 37.43. The velocity structure of the ionized gas is complex and cannot be explained globally by a simple dynamical model. The spectra from the clouds are inconsistent with shock or ``shock + precursor'' ionization models, but they are consistent with photoionization by the quasar nucleus. The best-fit photoionization model requires a low-metallicity (12+log(O/H) < 8.7) two-phase medium, consisting of a matter-bounded diffuse component with a unity filling-factor (N ~ 1 \cc, T ~ 15000 K), in which are embedded small, dense clouds (N ~ 400 \cc, T ~ 10^4 K). The high-density clouds are transient and can be re-generated through compressing the diffuse medium by low-speed shocks (V_S \lesssim 100 \kms). Our photoionization model gives a total mass for the ionized gas of about 3x10^{10} M_sun, and the total kinetic energy implied by this mass and the observed velocity field is ~2x10^{58} ergs. The fact that luminous EELRs are confined to steep-spectrum radio-loud quasars, yet show no morphological correspondence to the radio jets, suggests that the driving force producing the 4C 37.43 EELR was a roughly spherical blast wave initiated by the production of the jet. That such a mechanism seems capable of ejecting a mass comparable to that of the total interstellar medium of the Milky Way suggests that ``quasar-mode'' feedback may indeed be an efficient means of regulating star formation in the early universe.

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