Résumé / Abstract Journal-club_Galaxies

Séminaire/Seminar Galaxies

« 3D clustering and connectivity of critical points with Lyman-alpha tomography: forecasts for WEAVE-QSO »

Katarina Kraljic
Lab. Astroph. Marseille (LAM) (Marseille, France)

The upcoming WEAVE-QSO survey will target a high density of quasars over
a large area, enabling the reconstruction of the 3D density field
through Lyman-alpha tomography over unprecedented volumes smoothed on
intermediate cosmological scales. We produce mocks of the Lyman-alpha
forest using LyMAS, and reconstruct the 3D density field between
sightlines through Wiener filtering in a configuration compatible with
the future WEAVE-QSO observations. The fidelity of the reconstruction is
assessed by measuring one- and two-point statistics from the
distribution of critical points in the cosmic web. The reconstruction
captures well the expected features in the auto- and cross-correlations
of the critical points. This remains true after a realistic noise is
added to the synthetic spectra, even though sparsity of sightlines
introduces systematics, especially in the cross-correlations of points
with mixed signature. Specifically, the most striking clustering
features involving filaments and walls could be measured with up to 4
sigma of significance with a WEAVE-QSO-like survey. Moreover, the
connectivity of each peak identified in the reconstructed field is
globally consistent with its counterpart in the original field,
indicating that the reconstruction preserves the geometry of the density
field not only statistically, but also locally. Hence the critical
points relative positions within the tomographic reconstruction could be
used as standard rulers for dark energy by WEAVE-QSO and similar
surveys.
jeudi 9 juin 2022 - 11:30
Salle des séminaires Évry Schatzman
Institut d'Astrophysique de Paris
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