Local Luminous AGN with Matched Analogs

Our two-headed LLAMA consists of a sample of luminous AGNs and a matched sample of inactive galaxies.

Rationale and sample

The AGN phenomenon is likely short-lived. Statistical evidence, e.g. from the fraction of X-ray bright, optically normal galaxies (XBONGs), as well as hydrodynamical simulations indicate that a particular AGN phase may only last for as little as 105 years. It is therefore not surprising that little differences between the host galaxy properties of active and inactive galaxies are found when assessing e.g. the host galaxy morphology which will only change on dynamical times much larger than the AGN timescale.We have therefore set up a unique study to compare the nuclear inventory of AGNs and inactive galaxy in a comprehensive way. For this we first selected the twenty most luminous local AGNs based on the sensitive ultra hard X-ray all-sky survey provided by the Swift/BAT satellite. The rationale for this selection is to only select AGNs where coherent inflow mechanisms are required due to the large luminosity or mass accretion. We further require the galaxies to be local in order to resolve the nuclear region, in particular the nuclear stellar cluster on scales of 50-100 pc. And finally we employ the ultra hard X-ray band to be largely unimpeded by obscuration which can severly affect AGN selection based on optical properties. 

The so selected AGN sample is accompanied by a sample of inactive galaxies (where no ultra hard X-ray emission has been detected) that are matched in host galaxy properties to the active sample. This sample of 39 galaxies in total is currently being observed or observations are planned with VLT/X-SHOOTER, VLT/SINFONI, APEX as well as ALMA and HST.

Team members

Ric Davies (PI, MPE), Thaisa Storchi-Bergmann (Co-PI, UFGRS, Brazil), Leonard Burtscher (MPE), Reinhard Genzel (MPE), Erin Hicks (University of Alaska, US), Kotaro Kohno (Tokio University, Japan), Mike Koss (ETH Zürich, Switzerland), Dieter Lutz (MPE), Witold Maciejewski (Astrophysics Research Institute, Liverpool, UK), Francisco Müller-Sánchez (University of Colorado, US), Gilles Orban de Xivry (Université de Liège), David Rosario (Durham Universtiy, UK) Rogemar A. Riffel (UFSM, Brazil), Rogério Riffel (UFGRS, Brazil), Marc Schartmann (Swinburne University, UK), Allan Schnorr-Müller (UFGRS, Brazil), Amiel Sternberg (Tel Aviv University, Israel), Eckhard Sturm (MPE), Linda Tacconi (MPE), Sylvain Veilleux (University of Maryland, US)



The LLAMA logo animal is a picture kindly provided by Colin Richmond's Colin's Creatures.

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