Coffee talks
Friday 23/02/2024 @ 11:30, Sala riunioni quarto piano e on-line (meet.google.com/sue-bwvk-axf)
Silvia Belladitta (Max-Planck-Institute for Astronomy, Heidelberg, Germany), "Blazar discovery at z=7: implications for the Early Universe"
Relativistic jets are thought to play a crucial role in the formation of massive galaxies and supermassive black holes (SMBHs). However, little is known about radio-loud sources at the end of or within the epoch of reionization, and this represents a fundamental lack for future studies of 21-cm absorption within the reionization epoch. In this talk, I will present the discovery of the most distant radio-loud quasar known to date, at z=7.0, and a suite of multiwavelength observations that reveal that the source is a blazar, i.e., a radio-loud quasar with jets pointing toward the Earth. The existence of this blazar implies that there must be hundreds of similar (unaligned) radio sources awaiting to be discovered at z>~7. I will discuss here our on-going characterisation from low-frequency radio observations to X-rays. I will cover its black hole, jet, and host-galaxy properties. Finally, I will discuss the prospects of using this source for 21 cm absorption studies based on my GMRT and LOFAR programs.