The host galaxy properties of variability selected AGN in the Pan-STARRS1 Medium-Deep Survey

TL;DR

This study analyzes the properties of 975 variability-selected AGN from the Pan-STARRS1 survey, revealing correlations between AGN luminosity, host galaxy mass, and star formation, and comparing these hosts to control galaxies across multiple wavelengths.

Contribution

It provides a comprehensive multi-wavelength analysis of AGN host galaxy properties, highlighting differences from control galaxies and the relationship between AGN activity and star formation.

Findings

AGN variability amplitude decreases with luminosity

AGN hosts are more massive than control galaxies

Positive correlation between AGN luminosity and SFR

Abstract

We study the properties of 975 active galactic nuclei (AGN) selected by variability in the Pan-STARRS1 Medium-Deep Survey. Using complementary multi wavelength data from the ultraviolet to the far-infrared, we use SED fitting to determine the AGN and host properties at $z<1$, and compare to a well-matched control sample. We confirm the trend previously observed that the variability amplitude decreases with AGN luminosity, but on the other hand, we observe that the slope of this relation steepens with wavelength resulting in a "redder when brighter" trend at low luminosities. Our results show that AGN are hosted by more massive hosts than control sample galaxies, while the restframe, dust-corrected $NUV-r$ color distribution of AGN hosts is similar to control galaxies. We find a positive correlation between the AGN luminosity and star formation rate (SFR), independent of redshift. AGN hosts populate the whole range of SFRs within and outside the Main Sequence of star forming galaxies. Comparing the distribution of AGN hosts and control galaxies, we show that AGN hosts are less likely to be hosted by quiescent galaxies, but more likely to be hosted by Main Sequence or starburst galaxies.