FR-type radio sources at 3 GHz VLA-COSMOS: Relation to physical properties and large-scale environment

Context. Radio active galactic nuclei (AGN) are traditionally separated into two Fanaroff-Riley (FR) type classes, edge-brightened FRII sources or edge-darkened FRI sources. With the discovery of a plethora radio AGN different shapes, this dichotomy is becoming too simplistic in linking structure to physical properties AGN, their hosts, and environment. Aims. We probe large-scale environment faintest FR population date, link them structure. use VLA-COSMOS Large Project at 3 GHz (3 VLA-COSMOS), with resolution sensitivity 0.″75 2.3 μJy beam −1 explore down levels. Methods. classified objects as FRIs, FRIIs, hybrid FRI/FRII based on surface-brightness distribution along Our control sample was jet-less/compact (COM AGN), which show excess emission exceeding what coming from star-formation alone; excludes FRs. The largest angular projected sizes were measured by machine-learning algorithm also hand, following parametric approach classification. Eddington ratios calculated using scaling relations X-rays, we included jet power luminosity probe. Furthermore, investigated host (star-formation ratio, stellar mass, morphology), incidence within X-ray galaxy groups COSMOS, density fields cosmic-web probes COSMOS. Results. composed 59 32 FRI/FRIIs, 39 1818 COM 0.03 ≤ z 6. On average, have similar luminosities ( L ∼ 10 23 W Hz sr ), spanning range 21−26 , they lie median redshift 1. linear size FRIIs 106.6 36.9 238.2 kpc, larger than that FRI/FRIIs FRIs factor 2−3. smaller 30 value 1.7 1.5 4.7 kpc. ratio 0.006 0.005 0.007 2.5 less 2 higher FRI/FRII. When included, increase 12 15, respectively. FRs reside majority massive quenched hosts M * > 10.5 ⊙ older episodes linked lower group temperatures, suggesting radio-mode quenching. Regardless structure, found all types environments (group cluster, filaments, field). Conclusions. By relating luminosity, size, environment, find broad overlap populations. discuss need for classification scheme, expands classic taking consideration rather frequency-, sensitivity- resolution-dependent. This point crucial advent current future all-sky surveys.