Landing page for project EG142

Narrow-Line Seyfert 1 (NLS1) galaxies are active galactic nuclei (AGN) showing near-Eddington-level accretion onto (relatively) low-mass supermassive black holes. Only 7% of them are found to be radio-loud, much fewer than broad-line (BL) AGN. In a systematic study of the radio properties of NLS1 galaxies, we discovered an object showing a dramatic brightening with a factor of 20 at 1.4 GHz between the FIRST and the most recent RACS survey. The object is extremely compact at arcsec-scale according to the VLASS and RACS data. Our very recent Effelsberg measurements showed that it has a flat spectrum between 5 and 7 GHz, and that is still in a bright-state. While these properties may be explained by blazar-type variability from a relativistically-beamed jet, it does not show typical blazar features at other wavelengths. We speculate that the source underwent an accretion-mode change fundamentally increasing the jet emission. With the proposed observations, we will reveal the radio morphology of the source, whether it has a relativistically-beamed jet, or not.

This data is part of the archive of VLBI data maintained by JIVE on behalf of the EVN, a network of radio telescopes located primarily in Europe and Asia, with additional antennas in South Africa. The EVN archive itself has the DOI https://doi.org/10.17616/R3Z197