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arXiv 1108.2242astro-ph.CO
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邻近致密射电源的HI吸收

HI absorption towards nearby compact radio sources

Yogesh Chandola, S. K. Sirothia, D. J. Saikia

摘要:

我们目前的HI吸收测量结果对附近的紧凑陡谱(CSS)和千兆赫兹峰谱(GPS)的无线电源,CORALZ样本,使用巨型米波射电望远镜(GMRT)的样本。我们观察了18个源的样本,发现7个新的检测。这些来源是较低的光度比早期的研究CSS和GPS对象,我们调查任何依赖HI吸收功能的射电光度。在不确定性范围内,检测率和柱密度与更明亮的物体相似,GPS物体的检测率比CSS物体更高。蓝移的吸收功能,这可能是由于喷云相互作用的相对速度,是在$\sim$ $-$ 250公里秒$^{-1}$,并没有出现延伸到1000公里秒$^{-1}$看到更明亮的对象的值。这可能是由于这些物体中的喷流较弱,但需要从更大样本的源观测中确认。似乎没有任何证据表明HI柱密度依赖于光度或红移,但这些新的检测与HI柱密度和投影线性尺寸之间的反比关系是一致的。

英文摘要:

We present the results of HI absorption measurements towards a sample of nearby Compact Steep-Spectrum (CSS) and Giga-Hertz Peaked Spectrum (GPS) radio sources, the CORALZ sample, using the Giant Metrewave Radio Telescope (GMRT). We observed a sample of 18 sources and find 7 new detections. These sources are of lower luminosity than earlier studies of CSS and GPS objects and we investigate any dependence of HI absorption features on radio luminosity. Within the uncertainties, the detection rates and column densities are similar to the more luminous objects, with the GPS objects exhibiting a higher detection rate than for the CSS objects. The relative velocity of the blueshifted absorption features, which may be due to jet-cloud interactions, are within $\sim$$-$250 km s$^{-1}$ and do not appear to extend to values over 1000 km s$^{-1}$ seen for the more luminous objects. This could be due to the weaker jets in these objects, but requires confirmation from observations of a larger sample of sources. There appears to be no evidence of any dependence of HI column density on either luminosity or redshift, but these new detections are consistent with the inverse relation between HI column density and projected linear size.

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。

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