The effect of our local motion on the Sandage-Loeb test of the cosmic expansion

Abstract

Redshifts of an astronomical body measured at multiple epochs (e.g., separated by 10 years) are different due to the cosmic expansion. This so-called Sandage-Loeb test offers a direct measurement of the expansion rate of the Universe. However, acceleration in the motion of Solar System with respect to the cosmic microwave background also changes redshifts measured at multiple epochs. If not accounted for, it yields a biased cosmological inference. To address this, we calculate the acceleration of Solar System with respect to the Local Group of galaxies to quantify the change in the measured redshift due to local motion. Our study is motivated by the recent determination of the mass of Large Magellanic Cloud (LMC), which indicates a significant fraction of the Milky Way mass. We find that the acceleration towards the Galactic Center dominates, which gives a redshift change of 7 cm/s in 10 years, while the accelerations due to LMC and M31 cannot be ignored depending on lines of sight. We create all-sky maps of the expected change in redshift and the corresponding uncertainty, which can be used to correct for this effect.

arXiv comment6 pages, 3 figures. Accepted for publication in PASJ

References in corpus (20)

• The Structure of Cold Dark Matter Halos
• The Galaxy in Context: Structural, Kinematic and Integrated Properties
• Response of dark matter halos to condensation of baryons: cosmological simulations and improved adiabatic contraction model
• Third-Epoch Magellanic Cloud Proper Motions I: HST/WFC3 data and Orbit Implications
• The total mass of the Large Magellanic Cloud from its perturbation on the Orphan stream
• Cosmic dynamics in the era of Extremely Large Telescopes
• Gamma-Ray Bursts From Neutron Star Phase Transitions
• Direct Measurement of Cosmological Parameters from the Cosmic Deceleration of Extragalactic Objects
• A timing constraint on the (total) mass of the Large Magellanic Cloud
• The Half Million Quasars (HMQ) Catalogue
• And yet it moves: The dangers of artificially fixing the Milky Way center of mass in the presence of a massive Large Magellanic Cloud
• Response of the Milky Way's disc to the Large Magellanic Cloud in a first infall scenario
• VLBI measurement of the secular aberration drift
• Exploring the Dark Energy Redshift Desert with the Sandage-Loeb Test
• Real-time Cosmology
• The time evolution of cosmological redshift as a test of dark energy
• Optical drift effects in general relativity
• Direction and redshift drifts for general observers and their applications in cosmology
• Mapping the galactic gravitational potential with peculiar acceleration
• Peculiar acceleration

Cited by in corpus (5)

• Redshift drift cosmography for model-independent cosmological inference
• Perturbations of Cosmological Redshift Drift
• The ESPRESSO Redshift Drift Experiment I -- High-resolution spectra of the Lyman-$\alpha$ forest of QSO J052915.80-435152.0
• Intensity correlation speckles as a technique for removing Doppler broadening
• Redshift Drift fluctuations from N-body simulations