| Title: |
Testing Bayesian reconstruction methods from peculiar velocities |
| Authors: |
Valade, Aurélien; Libeskind, Noam I.; Hoffman, Yehuda; Pfeifer, Simon |
| Contributors: |
Institut de Physique des 2 Infinis de Lyon (IP2I Lyon); Université Claude Bernard Lyon 1 (UCBL); Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS) |
| Source: |
Mon.Not.Roy.Astron.Soc. ; https://hal.science/hal-03791666 ; Mon.Not.Roy.Astron.Soc., 2023, 519 (2), pp.2981-2994 |
| Publisher Information: |
HAL CCSD |
| Publication Year: |
2023 |
| Subject Terms: |
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]; stat |
| Description: |
International audience ; Reconstructing the large scale density and velocity fields from surveys of galaxy distances, is a major challenge for cosmography. The data is very noisy and sparse. Estimated distances, and thereby peculiar velocities, are strongly affected by the Malmquist-like lognormal bias. Two algorithms have been recently introduced to perform reconstructions from such data: the Bias Gaussian correction coupled with the Wiener filter (BGc/WF) and the HAMLET implementation of the Hamiltonian Monte Carlo forward modelling. The two methods are tested here against mock catalogs that mimic the Cosmicflows-3 data. Specifically the reconstructed cosmography and moments of the velocity field (monopole, dipole) are examined. A comparison is made to the ``exact'' wiener filter as well - namely the Wiener Filter in the unrealistic case of zero observational errors. This is to understand the limits of the WF method. The following is found. In the nearby regime ($d \lesssim 40 {\rm Mpc}/h$) the two methods perform roughly equally well. HAMLET does slightly better in the intermediate regime ($ 40 \lesssim d \lesssim 120 {\rm Mpc}/h$). The main differences between the two appear in the most distant regime ($d \gtrsim 120 {\rm Mpc}/h$), close to the edge of the data. The HAMLET outperforms the BGc/WF in terms of better and tighter correlations, yet in the distant regime the HAMLET yields a somewhat biased reconstruction. Such biases are missing from the BGc/WF reconstruction. In sum, both methods perform well and create reliable reconstructions with significant differences apparent when details are examined. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
https://hal.science/hal-03791666 |
| Availability: |
https://hal.science/hal-03791666 |
| Rights: |
undefined |
| Accession Number: |
edsbas.BE0606DA |
| Database: |
BASE |