We report the discovery of an ultraluminous X-ray source (ULX; CXO J133815.6+043255) in NGC 5252. This ULX is an off-nuclear point source, which is 22″ away from the center of NGC 5252, and has an X-ray luminosity of 1.5 × 1040 erg s-1. It is one of the rare examples of a ULX, which exhibits clear counterparts in radio, optical, and UV bands. A follow-up optical spectrum of the ULX shows strong emission lines. The redshift of the [O iii] emission line coincides with the systematic velocity of NGC 5252, suggesting that the ULX is gravitationally bound to NGC 5252. The flux of [O iii] appears to be correlated with both X-ray and radio luminosity in the same manner as ordinary active galactic nuclei (AGNs), indicating that the [O iii] emission is intrinsically associated with the ULX. Based on the multiwavelength data, we argue that the ULX is unlikely to be a background AGN. A more likely option is an accreting black hole with a mass of , which might be a stripped remnant of a merging dwarf galaxy.

Kim, M., Ho, L.C., Wang, J., Fabbiano, G., Bianchi, S., Cappi, M., et al. (2015). An off-nucleus nonstellar black hole in the seyfert galaxy NGC 5252. THE ASTROPHYSICAL JOURNAL, 814(1), 8 [10.1088/0004-637X/814/1/8].

An off-nucleus nonstellar black hole in the seyfert galaxy NGC 5252

BIANCHI, STEFANO;
2015-01-01

Abstract

We report the discovery of an ultraluminous X-ray source (ULX; CXO J133815.6+043255) in NGC 5252. This ULX is an off-nuclear point source, which is 22″ away from the center of NGC 5252, and has an X-ray luminosity of 1.5 × 1040 erg s-1. It is one of the rare examples of a ULX, which exhibits clear counterparts in radio, optical, and UV bands. A follow-up optical spectrum of the ULX shows strong emission lines. The redshift of the [O iii] emission line coincides with the systematic velocity of NGC 5252, suggesting that the ULX is gravitationally bound to NGC 5252. The flux of [O iii] appears to be correlated with both X-ray and radio luminosity in the same manner as ordinary active galactic nuclei (AGNs), indicating that the [O iii] emission is intrinsically associated with the ULX. Based on the multiwavelength data, we argue that the ULX is unlikely to be a background AGN. A more likely option is an accreting black hole with a mass of , which might be a stripped remnant of a merging dwarf galaxy.
2015
Kim, M., Ho, L.C., Wang, J., Fabbiano, G., Bianchi, S., Cappi, M., et al. (2015). An off-nucleus nonstellar black hole in the seyfert galaxy NGC 5252. THE ASTROPHYSICAL JOURNAL, 814(1), 8 [10.1088/0004-637X/814/1/8].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/298063
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