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arXiv 0908.0652astro-ph.CO
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微波选择(WMAP)耀变体和射电星系的计数、光度函数和演化

The number counts, luminosity functions and evolution of microwave-selected (WMAP) blazars and radio galaxies

P. Giommi, S. Colafrancesco, P. Padovani, D. Gasparrini, E. Cavazzuti, S. Cutini

摘要:

(摘要)我们进行了广泛的搜索,以确定WMAP 3年目录中列出的所有源的对应物,使用文献和档案数据。我们的工作导致了309个WMAP源的识别,其中98%是耀变体,射电类星体或射电星系。目前,由于缺乏光学光谱数据或清晰的无线电对应物,仍有15个物体无法识别。我们的研究结果使我们能够定义一个通量有限的样品203高银河纬度微波源($f_{41GHz} \ge 1$ JY,$|b_{\rm II}| > 15^\circ$),这是几乎完全确定(99%)。微波波段是blazar统计研究的理想波段,因为这是电磁光谱中受不同来源光谱分量叠加影响最小的部分。利用这些数据,我们导出了耀变体和射电星系在微波频率下的计数、光度函数和宇宙学演化。我们的结果与在射频上的结果一致。5 GHz的二元耀变体光度函数与DXRBS巡天的光度函数相似,这表明该样本代表了41 GHz的耀变体。微波选择的宽线类星体比BL Lac多6倍,一旦考虑到光谱选择效应,这个比例与无线电和伽马射线频率相似或更大。这有力地表明,在所有耀变体中,产生伽马射线的机制在一级上是相同的。我们的研究结果证实了Giommi & Colafrancesco(2004,2006)的发现,耀变体和射电星系是CMB各向异性图的最大污染物。我们预测这些源也是明亮的伽马射线源,其中大部分将被AGILE和FERMI探测到。

英文摘要:

(Abridged) We carried out an extensive search to identify the counterparts of all the sources listed in the WMAP 3-yr catalogue using literature and archival data. Our work led to the identification of 309 WMAP sources, 98% of which are blazars, radio quasars or radio galaxies. At present, 15 objects still remain without identification due to the lack of optical spectroscopic data or a clear radio counterpart. Our results allow us to define a flux limited sample of 203 high Galactic latitude microwave sources ($f_{41GHz} \ge 1$ Jy, $|b_{\rm II}| > 15^\circ$) which is virtually completely identified (99%). The microwave band is ideally suited for blazar statistical studies since this is the part of the em spectrum that is least affected by the superposition of spectral components of different origin. Using this data-set we derived number counts, luminosity functions and cosmological evolution of blazars and radio galaxies at microwave frequencies. Our results are in good agreement with those found at radio frequencies. The 5 GHz bivariate blazar luminosity functions are similar to those derived from the DXRBS survey, which shows that this sample is representative of the blazar population at 41 GHz. Microwave selected broad- lined quasars are about 6 times more abundant than BL Lacs, a ratio that is similar to, or larger than, that seen at radio and gamma-ray frequencies, once spectral selection effects are taken into account. This strongly suggests that the mechanism responsible for the generation of gamma-rays is, at first order, the same in all blazar types. Our results confirm the findings of Giommi & Colafrancesco (2004, 2006) that blazars and radio galaxies are the largest contaminants of the CMB anisotropy maps. We predict that these sources are also bright gamma-ray sources, most of which will be detected by AGILE and FERMI.

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