J/A+A/659/A166 Catalogue of Cosmic Filaments (Carron Duque+, 2022)
A novel cosmic filament catalogue from SDSS data.
Carron Duque J., Migliaccio M., Marinucci D., Vittorio N.
<Astron. Astrophys. 659, A166 (2022)>
=2022A&A...659A.166C 2022A&A...659A.166C (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Redshifts
Keywords: large-scale structure of Universe - catalogs - methods: data analysis
Abstract:
In this work we present a new catalogue of cosmic filaments obtained
from the latest Sloan Digital Sky Survey (SDSS) public data. In order
to detect filaments, we implement a version of the
Subspace-Constrained Mean-Shift algorithm that is boosted by machine
learning techniques. This allows us to detect cosmic filaments as
one-dimensional maxima in the galaxy density distribution. Our
filament catalogue uses the cosmological sample of SDSS, including
Data Release 16, and therefore inherits its sky footprint (aside from
small border effects) and redshift coverage. In particular, this means
that, taking advantage of the quasar sample, our filament
reconstruction covers redshifts up to z=2.2, making it one of the
deepest filament reconstructions to our knowledge. We follow a
tomographic approach and slice the galaxy data in 269 shells at
different redshift. The reconstruction algorithm is applied to 2D
spherical maps. The catalogue provides the position and uncertainty of
each detection for each redshift slice. The quality of our detections,
which we assess with several metrics, show improvement with respect to
previous public catalogues obtained with similar methods. We also
detect a highly significant correlation between our filament catalogue
and galaxy cluster catalogues built from microwave observations of the
Planck Satellite and the Atacama Cosmology Telescope.
Description:
We present a new catalogue of cosmic filaments found with the SDSS
Data Release 16. We implemented a version of the Subspace Constrained
Mean Shift algorithm on spherical coordinates and applied it to thin
redshift slices in order to obtain a tomographic reconstruction of the
cosmic web.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
block1.dat 197 1920003 Block 1 of the catalogue, from LRG galaxies
between z=0.05 to z=0.45
block2.dat 197 1182526 Block 2 of the catalogue, from LRG galaxies
between z=0.45 to 0.7
block3.dat 197 1357525 Block 3 of the catalogue, from QSO and LRG
galaxies between z=0.6 to 2.2
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Byte-by-byte Description of file: block1.dat block2.dat block3.dat
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Bytes Format Units Label Explanations
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1- 7 I7 --- Index Index of the entry
9- 30 E22.20 deg RAdeg [] Right ascension (equatorial system J2000)
32- 54 E23.20 deg DEdeg Declination (equatorial system J2000)
56- 73 F18.16 --- Dens Density estimate (arbitrary units)
75- 93 F19.17 deg e_pos Estimated uncertainty on position
95-117 E23.17 --- gradRA Gradient (RA component)
119-141 E23.17 --- gradDE Gradient (dec component)
143-166 E24.20 deg Angle Angle of the filament with the parallels of
the sphere in these coordinates, in a
counter-clockwise direction
168-172 F5.3 --- zlow Start of the redshift bin
174-178 F5.3 --- zhigh End of the redshift bin
180-197 F18.16 --- iniDens Initial density estimate (arbitrary units)
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Acknowledgements:
Javier Carron Duque, javier.carron(at)roma2.infn.it
(End) Patricia Vannier [CDS] 27-Dec-2021