Galaxy and Mass Assembly (GAMA)

Mid-infrared properties as tracers of galaxy environment

¹ Astronomical Observatory of the Jagiellonian University, ul. Orla 171, 30-244 Kraków, Poland
e-mail: usureshkumar@oa.uj.edu.pl
² National Centre for Nuclear Research, ul. Pasteura 7, 02-093 Warsaw, Poland
³ Center for Theoretical Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
⁴ Centre for Astrophysics and Supercomputing, Swinburne University of Technology, John Street, Hawthorn 3122, Australia
⁵ Department of Physics and Astronomy, University of the Western Cape, Robert Sobukwe Road, Bellville 7535, Republic of South Africa
⁶ ICRAR, The University of Western Australia, 7 Fairway, Crawley, WA 6009, Australia
⁷ Max Planck Institute for Extraterrestrial Physics, Gießenbachstraße, 85748 Garching b. München, Germany
⁸ Universitäts-Sternwarte, Fakultät für Physik, Ludwig-Maximilians-Universität München, Scheinerstr. 1, 81679 München, Germany
⁹ Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QH, UK
¹⁰ Sydney Institute for Astronomy, School of Physics, University of Sydney, Sydney, NSW 2006, Australia
¹¹ Centre of Excellence for All-Sky Astrophysics in 3D, Stromlo, ACT 2611, Australia

Received: 25 January 2022
Accepted: 2 November 2022

Abstract

Aims. We investigate how different mid-infrared (mid-IR) properties of galaxies are correlated with the environment in which the galaxies are located. For this purpose, we first study the dependence of galaxy clustering on the absolute magnitude at 3.4 μm and redshift. Then, we look into the environmental dependence of mid-IR luminosities and the galaxy properties derived from these luminosities. We also explore how various IR galaxy luminosity selections influence the galaxy clustering measurements.

Methods. We used a set of W1 (3.4 μm) absolute magnitude (M_W1) selected samples from the Galaxy and Mass Assembly (GAMA) survey matched with mid-IR properties from the Wide-field Infrared Survey Explorer (WISE) in the redshift range 0.07 ≤ z < 0.43. We computed the galaxy two-point correlation function (2pCF) and compared the clustering lengths between subsamples binned in M_W1 and in redshift. We also measured the marked correlation function (MCF), in which the galaxies are weighted by marks when measuring clustering statistics, using the luminosities in the WISE W1 to W4 (3.4 to 22 μm) bands as marks. Additionally, we compared the measurements of MCFs with different estimates of stellar mass and star formation rate (SFR) used as marks. Finally, we checked how different selections applied to the sample affect the clustering measurements.

Results. We show strong clustering dependence on the W1 absolute magnitude: galaxies brighter in the W1 band are more strongly clustered than their fainter counterparts. We also observe a lack of significant redshift dependence of clustering in the redshift range 0.07 ≤ z < 0.43. We show that although the W1 and W2 bands are direct indicators of stellar mass, a galaxy sample selected based on W1 or W2 bands does not perfectly show the clustering behaviour of a stellar mass-selected sample. The proxy relation between W3 and W4 bands and SFR is similar. We also demonstrate the influence of estimation techniques of stellar mass and SFR on the clustering measurements.