We present a novel algorithm to detect double nuclei galaxies (DNG) called GOTHIC (Graph BOosted iterated HIll Climbing) - that detects whether a given image of a galaxy has two or more closely separated nuclei. Our aim is to detect samples of dual or multiple active galactic nuclei (AGN) in galaxies. Although galaxy mergers are common, the detection of dual AGN is rare. Their detection is very important as they help us understand the formation of supermassive black hole (SMBH) binaries, SMBH growth and AGN feedback effects in multiple nuclei systems. There is thus a need for an algorithm to do a systematic survey of existing imaging data for the discovery of DNGs and dual AGN. We have tested GOTHIC on a known sample of DNGs and subsequently applied it to a sample of a million SDSS DR16 galaxies lying in the redshift range of 0 to 0.75 approximately, and have available spectroscopic data. We have detected 159 dual AGN in this sample, of which 2 are triple AGN systems. Our results show that dual AGN are not common, and triple AGN even rarer. The color (u-r) magnitude plots of the DNGs indicate that star formation is quenched as the nuclei come closer and as the AGN fraction increases. The quenching is especially prominent for dual/triple AGN galaxies that lie in the extreme end of the red sequence.
翻译:我们提出一种新奇的算法,以探测双核星系(DNG),称为GETHIC(GMHC)的双核星系(GETHIC)(GMBBB 滚动螺旋攀升) — — 检测星系特定图像是否具有两个或更紧密分离的核核。 我们的目的是检测星系中双或多个活跃的银河核(AGN)的样本。 虽然星系合并很常见,但发现双AGN(DGN)是稀有的。发现这些星系非常重要,因为它们有助于我们理解超级黑洞(SMBH)的二进制(SMBH)二进制、SMBH和AGN的反馈效应。因此,有必要用算法系统对现有成像数据数据进行系统进行系统的系统系统化调查,以发现DNGNG和双星系的样本。我们的结果显示,GNG值的双G值(GNG)值比值大约为0.75,并且有极的两极。