Ionized Gas Kinematics around an Ultra-luminous X-ray Source in NGC 5252 : Additional Evidence for an Off-nuclear AGN

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 GMOS 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] $\lambda$ 6584/H$\alpha$ 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.

to appear in ApJL

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Cited by in corpus (5)

• Hidden AGN in dwarf galaxies revealed by MaNGA: light echoes, off-nuclear wanderers, and a new broad-line AGN
• Metal-THINGS: On the metallicity and ionization of ULX sources in NGC 925
• Stellar Properties of the Host Galaxy of an Ultraluminous X-ray Source in NGC 5252
• BASS XLVII: 22 GHz Radio Atlas of Swift-BAT Selected AGN
• Identification of Intermediate-mass Black Hole Candidates Among a Sample of Sd Galaxies