A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems

Carolina Andonie, David M. Alexander, David Rosario, Brivael Laloux, Antonis Georgakakis, Leah K. Morabito, Carolin Villforth, Mathilda Avirett-Mackenzie, Gabriela Calistro Rivera, Agnese Del Moro, Sotiria Fotopoulou, Chris Harrison, Andrea Lapi, James Petley, Grayson Petter, Francesco Shankar

Research output: Working paper / PreprintPreprint

25 Downloads (Pure)


To understand the Active Galactic Nuclei (AGN) phenomenon and their impact on the evolution of galaxies, a complete AGN census is required; however, finding heavily obscured AGNs is observationally challenging. Here we use the deep and extensive multi-wavelength data in the COSMOS field to select a complete sample of 578 infrared (IR) quasars ($L_{\rm AGN,IR}>10^{45}\rm \: erg\: s^{-1}$) at $z10^{22}\rm \: cm^{-2}$) and identify differences in the average properties between the obscured and unobscured quasars: (1) obscured quasars have star-formation rates $\approx 3$ times higher than unobscured systems for no significant difference in stellar mass and (2) obscured quasars have stronger radio emission than unobscured systems, with a radio-loudness parameter $\approx 0.2 \rm \: dex$ higher. These results are inconsistent with a simple orientation model but in general agreement with either extreme host-galaxy obscuration towards the obscured quasars or a scenario where obscured quasars are an early phase in the evolution of quasars.
Original languageUndefined/Unknown
Publication statusPublished - 27 Sept 2022


  • astro-ph.GA

Cite this