Dipolar modulation in the size of galaxies: The effect of Doppler magnification

Abstract

Objects falling into an overdensity appear larger on its near side and smaller on its far side than other objects at the same redshift. This produces a dipolar pattern of magnification, primarily as a consequence of the Doppler effect. At low redshift this Doppler magnification completely dominates the usual integrated gravitational lensing contribution to the lensing magnification. We show that one can optimally observe this pattern by extracting the dipole in the cross-correlation of number counts and galaxy sizes. This dipole allows us to almost completely remove the contribution from gravitational lensing up to redshift 0.5, and even at high redshift z~1 the dipole picks up the Doppler magnification predominantly. Doppler magnification should be easily detectable in current and upcoming optical and radio surveys; by forecasting for telescopes such as the SKA, we show that this technique is competitive with using peculiar velocities via redshift-space distortions to constrain dark energy. It produces similar yet complementary constraints on the cosmological model to those found using measurements of the cosmic shear.

17 pages, 12 figures. v2: new example of signal-to-noise, minor changes, matches version accepted in MNRAS

References in corpus (14)

• A test of the nature of cosmic acceleration using galaxy redshift distortions
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Anisotropic galaxy clustering in Fourier-space
• New Perspective on Galaxy Clustering as a Cosmological Probe: General Relativistic Effects
• The shape of the SDSS DR5 galaxy power spectrum
• The 6dF Galaxy Survey: Peculiar Velocity Field and Cosmography
• Clustering of luminous red galaxies I: large scale redshift space distortions
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Cosmological implications of the Fourier space wedges of the final sample
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: On the measurement of growth rate using galaxy correlation functions
• Anti-lensing: the bright side of voids
• Scale Dependent Galaxy Bias in the SDSS as a function of Luminosity and Colour
• The linear growth rate of structure in Parametrized Post Friedmannian Universes
• Measuring cosmic velocities with 21cm intensity mapping and galaxy redshift survey cross-correlation dipoles
• A new method for the Alcock-Paczynski test
• On the perturbation of the luminosity distance by peculiar motions

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