Speaker
Description
PKS 2004-447 has been one of the five radio-loud Narrow-Line Seyfert 1 (NLS1) galaxies that were first discovered to carry a powerful relativistic jet. Despite being the radio-loudest among the original gamma-ray emitting NLS1 sample it is also among the most disputed NLS1s because its classification is not unambiguously clear. We show new results from a large multiwavelength program from radio to gamma-rays spanning more than five years from 2011 until 2017. We studied the longterm broadband spectral evolution of this unique object using a series of spectral energy distributions and parsec-scale resolution VLBI observations. The source continues to be unique among gamma-ray emitting NLS1 and intriguing in comparison to other radio-loud AGN as the multiwavelength data exhibit typical blazar-like characteristics while the radio data reveal a powerful one-sided and a consistent radio spectrum. The radio proerties are consistent with CSS sources, a class of radio-loud AGN that is usually associated with young radio sources.
