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Related papers: Revealing Hidden Cosmic Flows through the Zone of …

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Starting from the observed distribution of galaxy clusters in redshift space we use a two--step procedure to recover their distances and peculiar velocities. After statistically correcting for the unobserved cluster distribution in the zone…

Astrophysics · Physics 2016-08-30 E. Branchini , M. Plionis

We investigate how well the 3D density field of neutral hydrogen in the Intergalactic Medium (IGM) can be reconstructed using the Lyman-alpha absorptions observed along lines of sight to quasars separated by arcmin distances in projection…

Astrophysics · Physics 2008-01-29 S. Caucci , S. Colombi , C. Pichon , E. Rollinde , P. Petitjean , T. Sousbie

Various dynamically important extragalactic large-scale structures in the local Universe lie behind the Milky Way. Most of these structures (predicted and unexpected) have only recently been made ``visible'' through dedicated deep surveys…

Astrophysics · Physics 2015-06-24 Renee C. Kraan-Korteweg , Patrick A. Woudt

Dust extinction and stellar confusion by the Milky Way reduce the efficiency of detecting galaxies at low Galactic latitudes, creating the so-called Zone of Avoidance. This stands as a stumbling block in charting the distribution of…

Astrophysics of Galaxies · Physics 2015-06-23 K. Said , R. C. Kraan-Korteweg , T. H. Jarrett

We report the discovery of a potentially major supercluster that extends across the Galactic Plane in the constellation of Vela, at a mean recessional velocity of ~18,000 km/s. Recent multi-object spectroscopic observations of this Vela…

The local Universe provides a unique opportunity for testing cosmology and theories of structure formation. To facilitate this opportunity we present a new method for the reconstruction of the quasi-linear matter density and velocity fields…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-11 Yehuda Hoffman , Edoardo Carlesi , Daniel Pomarède , Hélène M. Courtois , Stefan Gottlöber , Noam I. Libeskind , Jenny G. Sorce , Gustavo Yepes

We describe a novel end-to-end approach using Machine Learning to reconstruct the power spectrum of cosmological density perturbations at high redshift from observed quasar spectra. State-of-the-art cosmological simulations of structure…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-21 Maria Han Veiga , Xi Meng , Oleg Y. Gnedin , Nickolay Y. Gnedin , Xun Huan

A reconstruction method for recovering the initial conditions of the Universe starting from the present galaxy distribution is presented which guarantees uniqueness of solutions. We show how our method can be used to obtain the peculiar…

Astrophysics · Physics 2007-05-23 Roya Mohayaee , Brent Tully , Uriel Frisch

The census of massive clusters of galaxies in the local Universe is almost complete, thanks to their prominent observational signatures at X-ray, optical, and sub-mm wavelengths. Nevertheless, a number of such systems are likely to be…

The reconstruction of the large scale velocity field from the grouped Cosmicflows-4 (CF4) database is presented. The lognormal bias of the inferred distances and velocities data is corrected by the Bias Gaussianization correction (BGc)…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-03 Yehuda Hoffman , Aurélien Valade , Noam I. Libeskind , Jenny G. Sorce , R. Brent Tully , Simon Pfeifer , Stefan Gottlöber , Daniel Pomaréde

The Reverse Zeldovich Approximation (RZA) is a reconstruction method which allows to estimate the cosmic displacement field from galaxy peculiar velocity data and to constrain initial conditions for cosmological simulations of the Local…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Timur Doumler , Helene Courtois , Stefan Gottloeber , Yehuda Hoffman

Volumetric phenomena, such as clouds and fog, present a significant challenge for 3D reconstruction systems due to their translucent nature and their complex interactions with light. Conventional techniques for reconstructing scattering…

Computer Vision and Pattern Recognition · Computer Science 2023-11-30 Jacob Lin , Miguel Farinha , Edward Gryspeerdt , Ronald Clark

Using third-order perturbation theory, we derive a relation between the mean divergence of the peculiar velocity given density and the density itself. Our calculations assume Gaussian initial conditions and are valid for Gaussian filtering…

Astrophysics · Physics 2015-06-24 Michal Chodorowski , Ewa Lokas , Agnieszka Pollo , Adi Nusser

A statistical method for reconstructing large scale structure behind the Zone of Avoidance is presented. It also corrects for shot-noise and for redshift distortion in galaxy surveys. The galaxy distribution is expanded in an orthogonal set…

Astrophysics · Physics 2007-05-23 Ofer Lahav

We present a method for reconstructing cosmological densityn for and velocity fields using the Lagrangian Zel'dovich formalism. . The method involves finding the least action solution for straight line particle paths in an evolving density…

Astrophysics · Physics 2015-06-24 R. A. C. Croft , E. Gaztanaga

In this paper, we introduce a Unet model of deep learning algorithms for reconstructions of the 3D peculiar velocity field, which simplifies the reconstruction process with enhanced precision. We test the adaptability of the Unet model with…

Instrumentation and Methods for Astrophysics · Physics 2024-06-21 Yuyu Wang , Xiaohu Yang

We present the reconstructed real-space density and the predicted velocity fields from the Two Mass Redshift Survey (2MRS). The 2MRS is the densest all-sky redshift survey to date and includes about 23,200 galaxies with extinction corrected…

Hydrodynamical simulations play a fundamental role in modern cosmological research, serving as a crucial bridge between theoretical predictions and observational data. However, due to their computational intensity, these simulations are…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-12 Andrés Caro , Daniel de Andres , Weiguang Cui , Gustavo Yepes , Marco De Petris , Antonio Ferragamo , Félicien Schiltz , Amélie Nef

Structure in the Universe is believed to have evolved out of quantum fluctuations seeded by inflation in the early Universe. These fluctuations lead to density perturbations that grow via gravitational instability into large cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-27 Aurelien Valade , Noam I. Libeskind , Daniel Pomarede , R. Brent Tully , Yehuda Hoffmann , Simon Pfeifer , Ehsan Kourkchi