NGC 5252: a pair of radio-emitting active galactic nuclei?
Journal article, 2016
The X-ray source CXO J133815.6+043255 has counterparts in the UV, optical, and radio bands. Based on the multiband investigations, it has been recently proposed by Kim et al. as a rarely seen off-nucleus ultraluminous X-ray (ULX) source with a black hole mass of ≥104 M⊙ in the nearby Seyfert galaxy NGC 5252. To explore its radio properties at very high angular resolution, we performed very long-baseline interferometry (VLBI) observations with the European VLBI Network (EVN) at 1.7 GHz. We find that the radio counterpart is remarkably compact among the known ULXs. It does not show a resolved structure with a resolution of a few milliarcsecond (mas), and the total recovered flux density is comparable to that measured in earlier sub-arcsecond-resolution images. The compact radio structure, the relatively flat spectrum, and the high radio luminosity are consistent with a weakly accreting supermassive black hole in a low-luminosity active galactic nucleus. The nucleus of NGC 5252 itself has similar radio properties. We argue that the system represents a relatively rare pair of active galactic nuclei, where both components emit in the radio.
galaxies: individual: NGC 5252 galaxies: jets radio continuum: galaxies X-rays: individual: CXO J133815.6+043255
Author
Xiaolong Yang
Chinese Academy of Sciences
Jun Yang
Chalmers, Earth and Space Sciences, Onsala Space Observatory
Z. Paragi
Joint Institute for VLBI in Europe
Xiang Liu
Chinese Academy of Sciences
T. An
Shanghai Astronomical Observatory Chinese Academy of Sciences
Chinese Academy of Sciences
Stefano Bianchi
Dipartimento di Matematica e Fisica
Luis C. Ho
Peking University
Lang Cui
Chinese Academy of Sciences
Wei Zhao
Chinese Academy of Sciences
Shanghai Astronomical Observatory Chinese Academy of Sciences
Xiaocong Wu
Chinese Academy of Sciences
Shanghai Astronomical Observatory Chinese Academy of Sciences
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 464 1 L70-L74 slw160Novel EXplorations Pushing Robust e-VLBI Services (NEXPReS)
European Commission (FP7) (261525), 2010-07-01 -- 2013-06-30.
Advanced Radio Astronomy in Europe (RADIONET3)
European Commission (FP7) (EC/FP7/283393), 2012-01-01 -- 2015-12-31.
Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
Infrastructure
Onsala Space Observatory
DOI
10.1093/mnrasl/slw160