Galaxy and Mass Assembly (GAMA)

Abstract

Context. Galaxies are biased tracers of the underlying network of dark matter. The strength of this bias depends on various galaxy properties, as well as on redshift. One of the methods used to study these dependences of the bias are measurements of galaxy clustering. Such studies are made using galaxy samples from various catalogues -frequently bearing their own problems related to sample selection methods. It is therefore crucial to understand how sample choice influences the clustering measurements, and which galaxy property is the most direct tracer of the galaxy environment. Aims. We investigate how different galaxy properties -luminosities in u, g, r, J, K-bands, stellar mass, star formation rate and specific star formation rate trace the environment in the local universe. We also study the effect of survey flux limits on galaxy clustering measurements. Methods. We measure the two-point correlation function (2pCF) and marked correlation functions (MCFs) using the aforementioned properties as marks. We use nearly stellar-mass-complete galaxy sample in the redshift range 0.1 < z < 0.16 from the Galaxy And Mass Assembly (GAMA) survey with a flux limit of r < 19.8. Further, we impose a brighter flux limit of r < 17.8 to our sample and repeat the measurements to study how this affects galaxy clustering analysis. We compare our results to measurements from the Sloan Digital Sky Survey (SDSS) with flux limits of r < 17.8 and r < 16.8. Results. We show that the stellar mass is the most direct tracer of galaxy environment, the K-band luminosity being a good substitute, although such a proxy sample misses close pairs of evolved, red galaxies. We also show that the u-band luminosity can be a proxy of star formation rate in the context of galaxy clustering. We observe an effect of the survey flux limit on clustering studies -samples with a higher flux limit (smaller magnitude) miss some information about close pairs of starburst galaxies.

Galaxy and Mass Assembly (GAMA)

“…We used galaxy 2pCF and MCF to quantify galaxy clustering and its dependence on environment. As this work is an extension of Sureshkumar et al (2021), all methods used in this study are the same as used therein. Therefore, we refer to Sect.…”

“…As described in Sect. 3.4 of Sureshkumar et al (2021), we used the singular-value decomposition method to estimate C−1 . This efficiently removed the influence of noisy eigenmodes of the covariance matrix and provided reliable power-law fit parameters.…”

“…3.4 for details). Quite a number of studies have used MCF to study the environmental dependence of galaxy properties such as luminosity, stellar mass, colour, age, morphology, SFR, and spin : Beisbart & Kerscher (2000), Skibba et al (2006), Skibba et al (2013), Sheth et al (2006), Gunawardhana et al (2018), Sureshkumar et al (2021), and Rutherford et al (2021). Additionally, Riggs et al (2021) used the MCF with group mass as a mark to study the clustering of galaxy groups.…”

“…The MCF is also used to constrain modified gravity theories (White 2016;Armijo et al 2018;Hernández-Aguayo et al 2018;Satpathy et al 2019;Alam et al 2021). Recently, Sureshkumar et al (2021) used MCFs to study how properties such as luminosities in u, g, r, J, K bands, stellar mass, SFR, and specific SFR trace small-scale clustering in the Galaxy and Mass Assembly (GAMA; Driver et al 2009) survey. We observed a hierarchy of luminosity passbands in which the redder K band appears to trace the galaxy clustering better than u, g, r, and J bands.…”

“…Because of its high completeness (> 98.5%) down to r < 19.8, GAMA has been abundantly used for clustering studies (e.g. Christodoulou et al 2012;Lindsay et al 2014;Farrow et al 2015;Loveday et al 2018;Gunawardhana et al 2018;Sureshkumar et al 2021). In particular, using the WISE photometry, the clustering of galaxies in the G12 region of GAMA was studied by Jarrett et al (2017).…”