Cosmic Flows surveys and CLUES simulations

TL;DR

The Cosmic Flows program aims to measure galaxy distances with high precision to improve local universe simulations and understand cosmic motions, including the cause of our galaxy's peculiar velocity.

Contribution

It introduces a large-scale, precise galaxy distance survey that enhances local universe modeling and investigates cosmic flow anomalies.

Findings

Reconstructed the Great Attractor region.

Achieved systematic errors below 2% in galaxy distances.

Provided insights into the origin of galaxy peculiar velocities.

Abstract

Cosmic Flows is a program to determine galaxy distances for 30,000 galaxies with systematic errors below 2%, almost ten times the number currently known and a five-fold improvement in systematics. The resultant velocity field will provide input for constrained local universe simulations: CLUES (www.clues-project.org). The observed and the simulated universe are then comparatively studied. This synergy of observations and theory distinguishes the program, and should lead to fundamental discoveries regarding the sources of deviations from the expansion of the universe. Specifically, the program should give a definitive answer to one of the most outstanding unsolved problem in cosmology: the cause of the motion of 630 km/s of our Galaxy manifested in the microwave background dipole. This paper presents current results with particular emphasis on the "great attractor" reconstruction.