论文标题
Lofar无线电选择类星体的光亮度函数$ 1.4 \ leq z \ leq5.0 $在NDWFS-BOOTES FIELD中
The optical luminosity function of LOFAR radio-selected quasars at $1.4\leq z\leq5.0$ in the NDWFS-Boötes field
论文作者
论文摘要
我们介绍了$ 9.3 \：\ 9.3 \：\ textrm {deg}^{2} $ noao theBoötestheBoötestheBoöteesField的光度光度函数（OLF）$ 1.4 <z <z <5.0 $ $ 9.3 \：\ textrm {deg}^{2} $ noaoboötectesField的$ 9.3 \：\：该选择基于用于训练三种不同的机器学习（ML）算法的光学/MID-IR光度法。必须在深度无线电图中以$5σ$的意义检测到ML算法作为类星体的对象，以归类为候选类星体。光学成像来自SDSS和PS1 $3π$调查； MID-IR光度法取自SDWFS调查；无线电数据是从NDWFS-Boötes领域的深Lofar成像中获得的。 $5σ$ lofar检测的需求使我们能够将样本中的恒星污染减少两个数量级。该样品包含134个对象，包括光学选择的候选类星体（47）和光谱确认的类星体（83）。我们的Lofar观测深度使我们能够检测出类似于射电Quiet的类星体的放射排放。样本中的类星体中的$ 65 \％$比$ m _ {\ textrm {1450}} = - 24.0 $，这是一个尚未通过无线电排放选择的olf olf进行的，尚未详细研究。已经证明，如果由于缺乏适当的数据而无法选择基于MID-IR楔形的AGN选择，则使用ML算法选择了使用光学/MID-IR光度法训练的ML算法与Lofar数据结合使用，为获取类似类的样品提供了出色的方法。我们证明RSQS显示的进化类似于微弱的类星体$（M _ {\ textrm {1450}}} \ leq-22.0）$。最后，我们发现RSQ可以组成整个微弱的类星体种群的最多$ \ sim20 \％$（无线电检测到无线电未搜索）。
We present an estimate of the optical luminosity function (OLF) of LOFAR radio-selected quasars (RSQs) at $1.4<z<5.0$ in the $9.3\:\textrm{deg}^{2}$ NOAO Deep Wide-field survey (NDWFS) of the Boötes field. The selection was based on optical/mid-ir photometry used to train three different machine learning (ML) algorithms. Objects taken as quasars by the ML algorithms are required to be detected at $5σ$ significance in deep radio maps to be classified as candidate quasars. The optical imaging came from the SDSS and the PS1 $3π$ survey; mid-ir photometry was taken from the SDWFS survey; and radio data was obtained from deep LOFAR imaging of the NDWFS-Boötes field. The requirement of a $5σ$ LOFAR detection allowed us to reduce the stellar contamination in our sample by two orders of magnitude. The sample comprises 134 objects, including both photometrically selected candidate quasars (47) and spectroscopically confirmed quasars (83). The depth of our LOFAR observations allowed us to detect the radio-emission of quasars that would be otherwise classified as radio-quiet. Around $65\%$ of the quasars in the sample are fainter than $M_{\textrm{1450}}=-24.0$, a regime where the OLF of quasars selected through their radio emission, has not been investigated in detail. It has been demonstrated that in cases where mid-ir wedge-based AGN selection is not possible due to a lack of appropriate data, the selection of quasars using ML algorithms trained with optical/mid-ir photometry in combination with LOFAR data provides an excellent approach for obtaining samples of quasars. We demonstrate that RSQs show an evolution similar to that exhibited by faint quasars $(M_{\textrm{1450}}\leq-22.0)$. Finally, we find that RSQs may compose up to $\sim20\%$ of the whole faint quasar population (radio-detected plus radio-undetected).
