arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1007.1659astro-ph.CO
收藏

AGN对亚毫米人群的贡献

The contribution of AGN to the sub-mm population

Michael D. Hill, Tom Shanks

摘要:

我们发现,在扩展钱德拉深场南部的X射线源是强烈的空间相关的LABOCA 870微米源。我们调查的依赖性,这种相关性的X射线通量,硬度比和列密度,发现特别微弱和吸收的X射线源是显着的亚毫米发射器。在X射线源红移子样本中,我们证实了以前的结果,即高光度源(L_X>10^44 ergs/s)具有更大的870 um通量,但我们也发现,这个子样本选择了对吸收源,在X射线通量微弱。总的来说,我们发现X射线源对亚毫米背景的贡献为1.5 \pm 0.1 Jy/deg^2,约占总数的3%,这与模糊活动星系核模型的预测一致,该模型也给出了与明亮亚毫米源计数的合理拟合。这个不统一的模型还表明,当康普顿厚度的X射线源被包括在内时,那么AGN对亚毫米背景的贡献将从~3%上升到25- 40%,尽管在统一的模型中AGN的贡献将仅达到~ 13%,因为X射线源的亚毫米通量更能代表整个AGN群体。测量的亚毫米通量对X射线通量,光度和柱密度的依赖关系都符合非统一AGN模型的预测。大量吸收的、X射线无法探测到的活动星系核可以解释我们在亚毫米级源和z > 0.5的红星系之间发现的进一步的互相关。我们的结论是,亚毫米星系可能包含长期寻求的吸收AGN人口需要解释的X射线背景。

英文摘要:

We find that X-ray sources in the Extended Chandra Deep Field South are strongly spatially correlated with LABOCA 870 micron sources. We investigate the dependence of this correlation on X-ray flux, hardness ratio and column density, finding that specifically faint and absorbed X-ray sources are significant sub-mm emitters. In the X-ray source redshift subsample we confirm the previous result that higher luminosity sources (L_X>10^44 ergs/s) have greater 870um fluxes but we also find that this subsample selects against absorbed sources, faint in X-ray flux. Overall, we find that X-ray sources contribute 1.5 \pm 0.1 Jy/deg^2 to the sub-mm background, ~3% of the total, in agreement with the prediction of an obscured AGN model which also gives a reasonable fit to the bright sub-mm source counts. This non-unified model also suggests that when Compton-thick, X-ray-undetected sources are included, then the fractional AGN contribution to the sub-mm background would rise from ~3% to a total of 25-40%, although in a unified model the AGN contribution would only reach ~13%, because the sub-mm flux of the X-ray sources is then more representative of the whole AGN population. Measurements of the dependence of sub-mm flux on X-ray flux, luminosity and column density all agree well with the predictions of the non-unified AGN model. Heavily absorbed, X-ray-undetected AGN could explain the further cross-correlation we find between sub-mm sources and z > 0.5 red galaxies. We conclude that sub-mm galaxies may contain the long-sought absorbed AGN population needed to explain the X-ray background.

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。

↑