Characterising filaments in the SDSS volume from the galaxy distribution [CEA]

http://arxiv.org/abs/2002.01486


Detecting the large-scale structure of the Universe from the galaxy distribution and characterising its components is of fundamental importance in astrophysics but also a difficult task to achieve. This is due to the necessity of having wide-area spectroscopic redshift surveys to accurately measure galaxy positions in space while also covering large areas of the sky, as well as to the difficulty of creating algorithms to extract cosmic web structures (e.g. filaments). Moreover, these detections will be affected by systematic uncertainties, stemming both from the characteristics of the survey used (e.g. its completeness and coverage) and from the unique properties of the specific method adopted to detect the cosmic web (i.e. the assumptions it relies on and the free parameters it may employ). For these reasons, the creation of new catalogues of cosmic web features on wide sky areas is important, as this allows users to have at their disposal a well understood sample of structures, whose systematic uncertainties have been thoroughly investigated. In this paper we present the filament catalogues created using the Discrete Persistent Structure Extractor (DisPerSE) tool in the Sloan Digital Sky Survey (SDSS) and we fully characterise them in terms of their dependence on the choice of parameters pertaining to the algorithm, as well as with respect to several systematic issues, which may arise in the skeleton due to the properties of the galaxy distribution (such as Finger-of-God redshift distortions and defects of the density field due to the boundaries of the survey). We create several fully characterised filament catalogues, which we make available to the scientific community upon request.

Read this paper on arXiv…

N. Malavasi, N. Aghanim, M. Douspis, et. al.
Thu, 6 Feb 20
56/57

Comments: 21 pages, 22 figures. Catalogue available upon request. Submitted to A&A. Feedback is welcome