Constraining baryonic physics with DES Y1 and Planck data: Combining galaxy clustering, weak lensing, and CMB lensing

We constrain cosmology and baryonic feedback scenarios with a joint analysis of weak lensing, galaxy clustering, cosmic microwave background (CMB) lensing, and their cross-correlations (so-called $6\ifmmode\times\else\texttimes\fi{}2$) using data from the Dark Energy Survey (DES) Y1 and the Planck satellite mission. Noteworthy features of our $6\ifmmode\times\else\texttimes\fi{}2$ pipeline are: We extend CMB lensing cross-correlation measurements to a band surrounding the DES Y1 footprint (around 25% gain in pairs), and we develop analytic covariance capabilities that account for different footprints and all cross-terms in the $6\ifmmode\times\else\texttimes\fi{}2$ analysis. We also measure the DES Y1 cosmic shear two-point correlation function (2PCF) down to $0{.}^{\ensuremath{'}}25$, but find that going below $2{.}^{\ensuremath{'}}5$ does not increase cosmological information due to shape noise. We model baryonic physics uncertainties via the amplitude of principal components (PCs) derived from a set of hydrosimulations. Given our statistical uncertainties, varying the first PC amplitude ${Q}_{1}$ is sufficient to model small scale cosmic shear 2PCF. For DES $\mathrm{Y}1+\mathrm{Planck}$ $6\ifmmode\times\else\texttimes\fi{}2$ we find ${S}_{8}=0.799\ifmmode\pm\else\textpm\fi{}0.016$, comparable to the $5\ifmmode\times\else\texttimes\fi{}2$ result of DES $\mathrm{Y}3+\mathrm{SPT}/\mathrm{Planck}$ ${S}_{8}=0.773\ifmmode\pm\else\textpm\fi{}0.016$. Combined with our most informative cosmology priors---baryon acoustic oscillation, big bang nucleosynthesis, type Ia supernovae, and Planck 2018 $\mathrm{EE}+\mathrm{lowE}$, we measure ${S}_{8}=0.817\ifmmode\pm\else\textpm\fi{}0.011$. Regarding baryonic physics constraints, our $6\ifmmode\times\else\texttimes\fi{}2$ analysis finds ${Q}_{1}=2.8\ifmmode\pm\else\textpm\fi{}1.8$. Combined with the aforementioned priors, it improves the constraint to ${Q}_{1}=3.5\ifmmode\pm\else\textpm\fi{}1.3$. For comparison, the strongest feedback scenario considered in this paper, the cosmo-OWLS AGN ($\mathrm{\ensuremath{\Delta}}{T}_{\mathrm{heat}}={10}^{8.7}\text{ }\text{ }\mathrm{K}$), corresponds to ${Q}_{1}=5.84$.