The Microjansky Radio Galaxy Population
The Microjansky Radio Galaxy Population
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Microjansky射电星系群
DOI：
10.1086/509102
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Wei
中科院分区：
文献类型：
--
作者：
A. Barger;A. Barger;L. Cowie;Wei
我们使用高度光谱完整的观测射电源从哈勃深场北地区的VLA 1.4 GHz的调查，研究微弱的射电星系的人口和它的演变。可以用光学光谱识别的部分与射电通量相当无关，在所有通量下识别出约60%-80%。我们光谱分类的源吸收，星星的形成者，塞弗特星系，和宽线活动星系，我们分析了它们的类型的属性。我们补充光谱红移与光度红移测量从静止帧紫外到中红外光谱能量分布。使用深X射线观测的领域，我们不确认存在的X射线无线电相关的恒星形成星系。我们也没有观察到1.4 GHz的流量和R星等或红移之间的任何相关性。我们发现，随着红移的增加，宿主星系的射电功率急剧上升，而光学性质的变化最多很小。假设本地确定的远红外无线电相关持有高红移，我们估计总的FIR亮度的无线电源。我们注意到，对于任何射电大活动星系核，我们保守地不试图从样本中去除，FIR光度估计将被高估。仅考虑类星体辐射热光度的射电源，我们发现候选的高度遮蔽活动星系核与X射线发光（L0.5-2 keV或L2-8 keV ≥ 1042 ergs-1）源的最大比值约为1.9。最后，我们使用源叠加分析来测量各种人群的X射线表面亮度。我们发现，我们的候选人高度模糊AGN的4-8 keV的光的贡献是非常小的，因此这些来源是无法解释的光，已建议可能会在这些能量失踪。
We use highly spectroscopically complete observations of the radio sources from the VLA 1.4 GHz survey of the Hubble Deep Field-North region to study the faint radio galaxy population and its evolution. The fraction that can be optically spectroscopically identified is fairly independent of radio flux, with about 60%-80% identified at all fluxes. We spectrally classify the sources as absorbers, star formers, Seyfert galaxies, and broad-line AGNs, and we analyze their properties by type. We supplement the spectroscopic redshifts with photometric redshifts measured from the rest-frame ultraviolet to mid-infrared spectral energy distributions. Using deep X-ray observations of the field, we do not confirm the existence of an X-ray-radio correlation for star-forming galaxies. We also do not observe any correlations between 1.4 GHz flux and R magnitude or redshift. We find that the radio powers of the host galaxies rise dramatically with increasing redshift, while the optical properties show at most small changes. Assuming that the locally determined far-infrared-radio correlation holds at high redshifts, we estimate total FIR luminosities for the radio sources. We note that the FIR luminosity estimates for any radio-loud AGNs, which we conservatively do not try to remove from the sample, will be overestimates. Considering only the radio sources with quasar-like bolometric luminosities, we find a maximum ratio of candidate highly obscured AGNs to X-ray-luminous (L0.5-2 keV or L2-8 keV ≥ 1042 ergs s-1) sources of about 1.9. Finally, we use source-stacking analyses to measure the X-ray surface brightnesses of various populations. We find the contributions to the 4-8 keV light from our candidate highly obscured AGNs to be very small, and hence these sources are unable to account for the light that has been suggested may be missing at these energies.