Emergent Gravity Fails to Explain Color-dependent Galaxy-Galaxy Lensing Signal from SDSS DR7

Abstract

© 2021. The American Astronomical Society. All rights reserved.We test Verlinde's Emergent Gravity (EG) theory using a galaxy-galaxy lensing technique based on Sloan Digital Sky Survey DR7 data. In the EG scenario, we do not expect a color dependence of the galaxy sample in the apparent dark matter predicted by EG, which is exerted only by the baryonic mass. If the baryonic mass is similar, then the predicted lensing profiles from the baryonic mass should be similar according to EG, regardless of the color of the galaxy sample. We use the stellar mass of the galaxy as a proxy of its baryonic mass. We divide our galaxy sample into five stellar mass bins, and further classify them as red and blue subsamples in each stellar mass bin. If we set the halo mass and concentration as free parameters, ΛCDM is favored by our data in terms of the reduced χ 2, while EG fails to explain the color dependence of the excess surface density from the galaxy-galaxy lensing measurement.