Speaker
Description
Recently, the discovery of so-called ``Little Red Dots'' by JWST has brought the topic of obscured Active Galactic Nuclei (AGN) to the forefront of observational astronomy. Although these systems are potentially quite surprising to see at high redshift, previous studies of obscured AGN have revealed a plethora of populations and properties (red quasars, ERQs, HoTDoGS, etc.). These dusty systems are often suggested to be the missing link in galaxy evolution between dusty starbursts and massive, quenched elliptical galaxies. Unfortunately, these systems make very poor targets for typical optical spectroscopic surveys (eg. SDSS or DESI) due to their relative faintness at similar redshifts and distinct spectral shapes from the general quasar population.
In this talk, we present our new strategy using Euclid Q1 data to identify near-IR AGN candidates and LOFAR-VLBI to pierce through the dust and confirm the presence of an AGN. This approach is similar in spirit to the FIRST-2MASS survey (Glikman et al. 2012) which uncovered an unusually high fraction of quasar outflows, a hint towards this evolutionary link. We explore the effectiveness of this selection in the Euclid Deep Field North, utilising existing spectra, and demonstrate that this AGN population is missed by many existing selection strategies. To improve the selection, we are also working to extend Marco Bondi's work on this field using recent improvements to the LOFAR-VLBI pipeline and combining 4 or more 8-hour observations. We derive suitable near-IR colour and radio flux cuts to enable the application of this selection to the massive Euclid DR1 + LoTSS DR3 dataset to be released next year. This will further be complemented by the ongoing WEAVE-LOFAR survey, which is not biased by reddening.
