Multiwavelength analysis of PBC J2333.9-2343

Nuclear activity as is observed in active galactic nuclei (AGN) might be a phase occurring in all galaxies, and this activity could be recurrent. A perfect laboratory to test these scenarios are the giant radio galaxies, since their emission can be as old as 10⁷-10⁸ years. In the present work we focus on the nucleus of PBC J2333.9-2343, which called our attention because it is a giant radio galaxy that shows different and incompatible classifications when observed at different frequencies, therefore being a good candidate to host different phases of AGN activity. Its optical spectrum is of a type 2 Seyfert, showing only narrow lines; its X-ray spectrum, conversely, does not show signs of absorption typical of a Seyfert 2 so has been classified as a type 1, and in the radio it has many features typical of a blazar and in fact is listed in the Roma BZCAT as an object of unknown type. One explanation for the different classifications of PBCJ2333.9-2343 might be attributed to variability, since the data used to classify this source were obtained on different dates. The alternative scenario is that the different classifications arise from an intrinsic property of the source.

We have analyzed simultaneous data at X-rays, optical, and radio frequencies to disentangle the nature of this AGN. We also used public data to study the variability properties of the source. Our results show that the nucleus of PBC J2333.9-2343 has undergone a change in the orientation of the jet and a transition in the accretion state.

02/12/2016 - 12:30
Dr. Lorena Hernández García
IAPS-INAF, Rome, Italia