TY - JOUR
T1 - Avoiding baryonic feedback effects on neutrino mass measurements from CMB lensing
AU - McCarthy, Fiona
AU - Foreman, Simon
AU - Van Engelen, Alexander
N1 - Funding Information:
We thank Mat Madhavacheril and Blake Sherwin for interesting discussions that provided motivation for this work, and we also thank Shahab Joudaki, Matthew Lewandowski, and Emmanuel Schaan for useful discussions. We thank Francisco Villaescusa-Navarro for measuring and providing IllustrisTNG power spectra used in this work, the OWLS and Horizon-AGN teams for making their power spectra publicly available, Mat Madhavacheril for making his forecasting code publicly available, and Eegene Chung for sharing her lensing and forecasting codes. Research at Perimeter Institute is supported in part by the Government of Canada through the Department of Innovation, Science and Industry Canada and by the Province of Ontario through the Ministry of Colleges and Universities. FMcC acknowledges support from the Vanier Canada Graduate Scholarships program.
Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/5/15
Y1 - 2021/5/15
N2 - A measurement of the sum of neutrino masses is one of the main applications of upcoming measurements of gravitational lensing of the cosmic microwave background (CMB). This measurement can be confounded by modelling uncertainties related to so-called "baryonic effects"on the clustering of matter, arising from gas dynamics, star formation, and feedback from active galactic nuclei and supernovae. In particular, a wrong assumption about the form of baryonic effects on CMB lensing can bias a neutrino mass measurement by a significant fraction of the statistical uncertainty. In this paper, we investigate three methods for mitigating this bias: (1) restricting the use of small-scale CMB lensing information when constraining neutrino mass; (2) using an external tracer to remove the low-redshift contribution to a CMB lensing map; and (3) marginalizing over a parametric model for baryonic effects on large-scale structure. We test these methods using Fisher matrix forecasts for experiments resembling the Simons Observatory and CMB-S4, using a variety of recent hydrodynamical simulations to represent the range of possible baryonic effects, and using cosmic shear measured by the Rubin Observatory's LSST as the tracer in method (2). We find that a combination of (1) and (2), or (3) on its own, will be effective in reducing the bias induced by baryonic effects on a neutrino mass measurement to a negligible level, without a significant increase in the associated statistical uncertainty.
AB - A measurement of the sum of neutrino masses is one of the main applications of upcoming measurements of gravitational lensing of the cosmic microwave background (CMB). This measurement can be confounded by modelling uncertainties related to so-called "baryonic effects"on the clustering of matter, arising from gas dynamics, star formation, and feedback from active galactic nuclei and supernovae. In particular, a wrong assumption about the form of baryonic effects on CMB lensing can bias a neutrino mass measurement by a significant fraction of the statistical uncertainty. In this paper, we investigate three methods for mitigating this bias: (1) restricting the use of small-scale CMB lensing information when constraining neutrino mass; (2) using an external tracer to remove the low-redshift contribution to a CMB lensing map; and (3) marginalizing over a parametric model for baryonic effects on large-scale structure. We test these methods using Fisher matrix forecasts for experiments resembling the Simons Observatory and CMB-S4, using a variety of recent hydrodynamical simulations to represent the range of possible baryonic effects, and using cosmic shear measured by the Rubin Observatory's LSST as the tracer in method (2). We find that a combination of (1) and (2), or (3) on its own, will be effective in reducing the bias induced by baryonic effects on a neutrino mass measurement to a negligible level, without a significant increase in the associated statistical uncertainty.
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U2 - 10.1103/PhysRevD.103.103538
DO - 10.1103/PhysRevD.103.103538
M3 - Article
AN - SCOPUS:85107345896
SN - 2470-0010
VL - 103
JO - Physical Review D
JF - Physical Review D
IS - 10
M1 - 103538
ER -