Constraining Extended Reionization Models Through Arcminute-Scale CMB Measurements
Abstract
The measurement of the optical depth to free electrons, taur, in the cosmic microwave background (CMB) provides an important constraint on reionization, but is degenerate to more complex reionization models. Small angular-scale CMB measurements of the kinetic Sunyaev-Zeldovich (kSZ) and Ostriker-Vishniac (OV) effects have the potential to break this degeneracy. We calculate the OV signal for various extended reionization histories described by a simple analytic form. These models are parametrized by dz, the duration of the reionization event. For reionization histories with identical values of taur, the OV amplitude at l = 3000 (C3000) differs by ~20 % between the models with dz = 0.1 and dz = 3.0. We demonstrate that the removal of the z < 6 component of the OV signal will significantly enhance the ability to differentiate between reionization histories, with C3000 varying by a factor of ~2 between the models with dz = 0.1 and dz = 3.0. If the low-redshift OV and related kSZ signal can be adequately subtracted, this would provide an important observational constraint on extended reionization models.
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.