2017/07/19 by Minjin Kim, Luis C. Ho, Myungshin Im · 12 citations
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Galaxy #Ionization #Physics #astro-ph.GA
paper · pdf · open access · doi:10.3847/2041-8213/aa7fe8
published in The Astrophysical Journal Letters 844(2), L21 (IOP Publishing) · to appear in ApJL
arxiv created 2017/07/19 · openalex publication_date 2017/07/27 · arxiv updated 2017/08/02 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/05
Abstract The Seyfert 2 galaxy NGC 5252 contains a recently identified ultra-luminous X-ray (ULX) source that has been suggested to be a possible candidate off-nuclear low-mass active galactic nucleus. We present follow-up optical integral-field unit observations obtained using Gemini Multi-Object Spectrographs on the Gemini-North telescope. In addition to confirming that the ionized gas in the vicinity of the ULX is kinematically associated with NGC 5252, the new observations reveal ordered motions consistent with rotation around the ULX. The close coincidence of the excitation source of the line-emitting gas with the position of the ULX further suggests that ULX itself is directly responsible for the ionization of the gas. The spatially resolved measurements of [N ii ] λ 6584/H α surrounding the ULX indicate a low gas-phase metallicity, consistent with those of other known low-mass active galaxies but not that of its more massive host galaxy. These findings strengthen the proposition that the ULX is not a background source but rather that it is the nucleus of a small, low-mass galaxy accreted by NGC 5252.