A Month in the Life

My first post closed with our plans for measuring the tiniest signals in the Cosmic Microwave Background (CMB), and our need to observe from the very quietest places we can find; this month has included the annual collaboration meetings for two of these projects.

LiteBIRD is a Japanese Space Agency (JAXA) project with US and European involvement to put a telescope in space to search specifically for the large-scale fluctuations in the “twisted” component of the CMB polarization. Called the B-mode, by analogy with the magnetic part of an electromagnetic (EB) field, the amplitude of its fluctuations on the largest angular scales is set by the energy scale of Inflation. Since the signal we’re looking for is on such large scales we can use a low-resolution telescope, which is important because mirror size is a huge driver in satellite cost. From space we’re also free of the atmosphere, which is a serious contaminant at microwave frequencies. In particular, and unlike from the ground, we can observe at the highest microwave frequencies where the polarized galactic dust is brightest in order to understand its distribution across the sky to help remove it from our maps of the CMB. Having collaborators on 3 continents makes scheduling conference calls challenging, so all being able to spend some time together in a single time zone is very precious. Satellite experiments also take extraordinary management, and we spent a lot of time working to align the schedules of the 3 space agencies involved, each of which has its own lengthy planning process including multiple go/no-go reviews.

The Simons Observatory is a suite of ground-based telescopes to be built in the high Atacama Desert in Northern Chile. Funded by the Simons and Heising-Simons Foundations and building on the existing Atacama Cosmology Telescope (ACT) and POLARBEAR/Simons Array (PB/SA) teams, the Simons Observatory will also use low-resolution telescopes to measure the energy scale of inflation, and also use high-resolution telescopes to enable the full range of cosmological and astrophysical science from the CMB. Even at 5200m though atmospheric water vapor prevents us from observing at the frequencies balloons and satellites can reach, so we are working hard to ensure that the highest frequency we can reach (270 GHz) will be sufficient to the task of dust removal. Here too, simply being in the same place for a few days was a huge benefit.

One challenge of being involved in so many fascinating projects is maintaining the balance between my work and home lives. This month has been particularly difficult, with two weeks away from home just as the school year was drawing to a close. It also means that my brewing schedule has to be carefully planned around my travel, and having arrived home late on Wednesday night I closed the month out with an impromptu brew day on Saturday to replenish my dwindling supplies of West Coast India Pale Ales!