Coffee talks
Friday 24/02/2023 @ 11:30, Sala riunioni quarto piano e on-line (meet.google.com/sue-bwvk-axf)
Giulia Migliori (INAF-IRA Bologna), "Bright X-ray Quasar Jets: how many radiative components?"
In any field of research, considering the state-of-art of our knowledge often boils down to choosing whether to see the glass half full or half empty. In this talk, I will first briefly illustrate the half empty and half full of powerful extragalactic X-ray jets, summarising the open questions and the progress made. Then I will focus on the case of the X-ray jet in the radio quasar RGB J1512+020A. The jet is among the brightest X-ray jets at low redshift (z<0.5) and has a relatively high jet-to-core X-ray flux ratio (~0.26), similar to high-z jets. Its main features are characterised by large X-ray-to-radio luminosity ratios (L_X/L_r up to ~50) in comparison with knots and hotspots of other known jets. For two of the jet’s components, archival ALMA data have unveiled a turnover of the radio synchrotron spectrum at ~460 GHz. This implies that the optical emission visible in DECaLS images is either due to the same radiative component responsible for the X-ray emission or to a third radiative component of unknown nature. I will discuss the different radiative scenarios and their implications for the jet physics and conclude with considerations on the relevance of our study to understanding the X-ray emission of high-redshift jetted quasars.