Galaxy and Mass Assembly (GAMA): tracing galaxy environment using the marked correlation function
journal contributionposted on 2023-06-10, 00:18 authored by U Sureshkumar, A Durkalec, A Pollo, M Bilicki, Jonathan LovedayJonathan Loveday, D J Farrow, B W Holwerda, A M Hopkins, J Liske, K A Pimbblet, E N Taylor, A H Wright
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.
- Accepted version
JournalAstronomy & Astrophysics
Department affiliated with
- Physics and Astronomy Publications
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