A1 Refereed original research article in a scientific journal
Galaxy and Mass Assembly (GAMA). The Properties of Quasar Host Galaxies: Star Formation Histories and Stellar Populations
Authors: Stone, Maria B.; De Propris, Roberto; Wethers, Clare; Kotilainen, Jari; Acharya, Nischal; Holwerda, Benne; Hopkins, Andrew M.; Pimbblet, Kevin
Publisher: Institute of Physics Publishing
Publication year: 2026
Journal: Astrophysical Journal
Article number: 143
Volume: 997
Issue: 2
ISSN: 0004-637X
eISSN: 1538-4357
DOI: https://doi.org/10.3847/1538-4357/ae2798
Publication's open availability at the time of reporting: Open Access
Publication channel's open availability : Open Access publication channel
Web address : https://iopscience.iop.org/article/10.3847/1538-4357/ae2798
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/515502570
Self-archived copy's licence: CC BY
Self-archived copy's version: Publisher`s PDF
We investigated the star formation history and stellar populations of a sample of 205 Type I quasar host galaxies (0.1 < z < 0.35) and compared them with normal (nonactive) galaxies of the same mass and redshift within the volume of the Galaxy and Mass Assembly redshift survey. We find that quasar host galaxies tend to be star-forming galaxies (∼80%) lying on the star-forming main sequence; the fraction of quasar host galaxies that are quiescent (∼20%) is lower than the fraction of quiescent galaxies in the comparison sample of normal galaxies (54%). We find that the mean star formation rate (SFR) of quasar host galaxies has increased over the past 100 Myr by a factor of 2–3, but these galaxies were star-forming at all times previously. Our data are more consistent with quasar activity originating together with an increase in the SFR of otherwise normal galaxies, similar to episodic star formation in normal spirals. We argue that this indicates that secular processes and minor mergers may be the favored triggers of nuclear activity in the local Universe.
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Funding information in the publication:
M.B.S. acknowledges the Finnish Cultural Foundation grant Nos. 00220968 and 00231098, the Academy of Finland grant No. 311438, and FINCA funding. M.B.S. acknowledges useful email discussions with Pekka Heinämäki, Johanna Hartke, Véronique Buat, Denis Burgarella, Kostas Kouroumpatzakis, Elina Lindfors, Talvikki Hovatta, and with GAZPAR support personnel for CIGALE, operated by CeSAM-LAM and IAP, support for GAMA survey questions from Ivan Baldry, Simon Driver, Jonathan Loveday, and Alister Graham, and James Stone, Kaj Wiik for help with the CIGALE installation, science discussions with the FINCA community, and feedback from the referee.
GAMA is a joint European-Australasian project based around a spectroscopic campaign using the Anglo-Australian Telescope. The GAMA input catalog is based on data taken from SDSS and the UKIRT Infrared Deep Sky Survey. Complementary imaging of the GAMA regions is being obtained by a number of independent survey programs, including the Galaxy Evolution Explorer (GALEX) Medium Imaging Survey (MIS), VLT Survey Telescope, KiDS, Visible and Infrared Survey Telescope for Astronomy (VISTA) Kilo-Degree Infrared Galaxy Survey (VIKING), Wide-Field Infrared Survey Explorer (WISE), Herschel-ATLAS, GMRT, and ASKAP, providing UV to radio coverage. GAMA is funded by the STFC (UK), the ARC (Australia), the AAO, and the participating institutions. The GAMA website is at http://www.gama-survey.org/.
This research has made use of the Spanish Virtual Observatory (https://svo.cab.inta-csic.es) project funded by MCIN/AEI/10.13039/501100011033/ through grant PID2020-112949GB-I00; the NASA/IPAC Extragalactic Database (NED), which is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology; StackOverflow platform, the VizieR database (F. Ochsenbein et al. 2000); Cosmology Calculator (E. L. Wright 2006), Seafile file collaboration platform.
