论文标题
巨大的射线星系在博物馆的深层领域
Giant radio galaxies in the LoTSS Boötes deep field
论文作者
论文摘要
巨大的射电星系（GRGS）是射电星系，根据定义，它们预测了超过700 kpc或1 MPC的线性范围。我们已经进行了仔细的视觉检查，以寻找150 MHz的引导者Lofar Deep Field（BLDF）图像的GRG。我们确定了74个GRG，其尺寸大于0.7 MPC，其中38个大于1 MPC。对于线性尺寸大于0.7（1）MPC的GRGS，所得的GRG天空密度约为每平方度的2.8（1.43）GRG。我们使用深度光学和红外调查数据研究了他们的无线电特性和宿主星系的积聚状态，并从54 MHz和1.4 GHz的可用调查图像中确定了这些GRG的通量密度，以获得集成的无线电光谱指数。我们在P-D图中显示了GRG的位置。 GRG宿主中央黑洞的积聚模式辐射效率低下，表明中央发动机在发射时没有进行大量积聚。有趣的是，可用光谱的35个GRG中有14个显示出中等的恒星形成率。基于从Desi DR9光度红移目录中获取的光学星系的数量密度，我们发现GRGS和其他射电星系环境之间没有显着差异，至少对于红移至Z = 0.7。
Giant radio galaxies (GRGs) are radio galaxies that have projected linear extents of more than 700 kpc or 1 Mpc, depending on definition. We have carried out a careful visual inspection in search of GRGs of the Bootes LOFAR Deep Field (BLDF) image at 150 MHz. We identified 74 GRGs with a projected size larger than 0.7 Mpc of which 38 are larger than 1 Mpc. The resulting GRG sky density is about 2.8 (1.43) GRGs per square degree for GRGs with linear size larger than 0.7 (1) Mpc. We studied their radio properties and the accretion state of the host galaxies using deep optical and infrared survey data and determined flux densities for these GRGs from available survey images at both 54 MHz and 1.4 GHz to obtain integrated radio spectral indices. We show the location of the GRGs in the P-D diagram. The accretion mode onto the central black holes of the GRG hosts is radiatively inefficient suggesting that the central engines are not undergoing massive accretion at the time of the emission. Interestingly, 14 out of 35 GRGs for which optical spectra are available show a moderate star formation rate. Based on the number density of optical galaxies taken from the DESI DR9 photometric redshift catalogue, we found no significant differences between the environments of GRGs and other radio galaxies, at least for redshift up to z = 0.7.
