# HST and LAMOST discover a dual active galactic nucleus in J0038+4128

 Title HST and LAMOST discover a dual active galactic nucleus in J0038+4128 Publication Type Journal Article Year of Publication 2014 Authors Huang, Y, Liu, X-W, Yuan, H-B, Xiang, M-S, Huo, Z-Y, Hou, Y-H, Jin, G, Zhang, Y, Zhou, X-L Journal \mnras Volume 439 Pagination 2927-2932 Keywords galaxies: active, galaxies: individual: J0038+4128, galaxies: interactions, galaxies: nuclei, galaxies: Seyfert Abstract {We report the discovery of a kiloparsec-scale dual active galactic nucleus (AGN) in J0038+4128. From the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2) images, we find two optical nuclei with a projection separation of 4.7 kpc (3.44 arcsec). The southern component (J0038+4128S) is spectroscopically observed with the HST Goddard High Resolution Spectrograph in the UV range and is found to be a Seyfert 1 galaxy with a broad Ly{$\alpha$} emission line. The northern component (J0038+4128N) is spectroscopically observed during the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (also named the Guoshoujing Telescope) pilot survey in the optical range. The observed line ratios as well as the consistency of redshift of the nucleus emission lines and the host galaxy's absorption lines indicate that J0038+4128N is a Seyfert 2 galaxy with narrow lines only. These results thus confirm that J0038+4128 is a Seyfert 1-Seyfert 2 AGN pair. The HST WFPC2 F336W/U-band image of J0038+4128 also reveals for the first time for a dual AGN system two pairs of bi-symmetric arms, as are expected from the numerical simulations of such system. Being one of a few confirmed kiloparsec-scale dual AGNs exhibiting a clear morphological structure of the host galaxies, J0038+4128 provides a unique opportunity to study the co-evolution of the host galaxies and their central supermassive black holes undergoing a merging process. } DOI 10.1093/mnras/stu334