English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Future CMB experiments will require exquisite control of systematics in orderto constrain the $B$-mode polarisation power spectrum. One class of systematicsthat requires careful study is instrumental systematics. The potential impactof such systematics is most readily understood by considering analysispipelines based on pair differencing. In this case, any differential gain,pointing or beam ellipticity between the two detectors in a pair can result inintensity leakage into the $B$-mode spectrum, which needs to be controlled to ahigh precision due to the much greater magnitude of the total intensity signalas compared to the $B$-mode signal. One well known way to suppress suchsystematics is through careful design of the scan-strategy, in particularmaking use of any capability to rotate the instrument about its pointing(boresight) direction. Here, we show that the combination of specific choicesof such partial boresight rotation angles with redundancies present in the scanstrategy is a powerful approach for suppressing systematic effects. Thismitigation can be performed in analysis in advance of map-making and, incontrast to other approaches (e.g. deprojection or filtering), results in nosignal loss. We demonstrate our approach explicitly with time ordered datasimulations relevant to next-generation ground-based CMB experiments, usingdeep and wide scan strategies appropriate for experiments based in Chile. Thesesimulations show a reduction of multiple orders of magnitude in the spurious$B$-mode signal arising from differential gain and differential pointingsystematics.

Controlling systematics in ground-based CMB surveys with partial boresight rotation