Constraints on Cosmology and Baryonic Feedback with the Deep Lens Survey Using Galaxy-Galaxy and Galaxy-Mass Power Spectra

TL;DR

This paper measures cosmological parameters using galaxy-galaxy and galaxy-mass power spectra from the Deep Lens Survey, constraining baryonic feedback effects and neutrino masses, and finds results consistent with Planck CMB data.

Contribution

It introduces a method to marginalize over baryonic feedback in power spectrum analysis and provides new constraints on feedback strength and neutrino masses.

Findings

Measured $S_8$ consistent with Planck and previous DLS results.

Constrained baryonic feedback parameter suggesting stronger AGN feedback.

Highlighted the importance of baryonic effects in cosmological parameter estimation.

Abstract

We present cosmological parameter measurements from the Deep Lens Survey (DLS) using galaxy-mass and galaxy-galaxy power spectra in the multipole range $\ell=250\sim2000$. We measure galaxy-galaxy power spectra from two lens bins centered at $z\sim0.27$ and $0.54$ and galaxy-mass power spectra by cross-correlating the positions of galaxies in these two lens bins with galaxy shapes in two source bins centered at $z\sim0.64$ and $1.1$. We marginalize over a baryonic feedback process using a single-parameter representation and a sum of neutrino masses, as well as photometric redshift and shear calibration systematic uncertainties. For a flat $\Lambda$CDM cosmology, we determine $S_8\equiv\sigma_8\sqrt{\Omega_m/0.3}=0.810^{+0.039}_{-0.031}$, in good agreement with our previous DLS cosmic shear and the Planck Cosmic Microwave Background (CMB) measurements. Without the baryonic feedback marginalization, $S_8$ decreases by $\sim0.05$ because the dark matter-only power spectrum lacks the suppression at the highest $\ell$'s due to Active Galactic Nuclei (AGN) feedback. Together with the Planck CMB measurement, we constrain the baryonic feedback parameter to $A_{baryon}=1.07^{+0.31}_{-0.39}$, which suggests an interesting possibility that the actual AGN feedback might be stronger than the recipe used in the OWLS simulations. The interpretation is limited by the validity of the baryonic feedback simulation and the one-parameter representation of the effect.