NGC 5252: a pair of radio-emitting active galactic nuclei?
Artikel i vetenskaplig tidskrift, 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


Xiaolong Yang

Chinese Academy of Sciences

Jun Yang

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

Z. Paragi

Joint Institute for VLBI in Europe

Xiang Liu

Chinese Academy of Sciences

T. An

Shanghai Astronomical Observatory

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

Xiaocong Wu

Chinese Academy of Sciences

Shanghai Astronomical Observatory

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 464 L70-L74 slw160


Astronomi, astrofysik och kosmologi


Grundläggande vetenskaper


Onsala rymdobservatorium