Constraining reionization with the global 21 cm signal and kinetic Sunyaev-Zel'dovich effect
What does it look like when two signals are complementary probes of reionization? In this project, we confirm the intuition that the global 21 cm signal and kinetic Sunyaev-Zeldovich effect (kSZ) are sensitive to different modes of the ionization history. The 21cm signal is expected to be most sensitive to rapidly evolving modes since it is difficult to decouple from spectrally smooth foreground contaminants. On the other hand, the kSZ is more sensitive to extended modes since it is sourced by the patchiness of reionization and integrated through cosmic time. By decomposing simulated covariances in the Karhunen-Loeve eigenvalue basis, we can order modes of reionization according to relative 21cm-kSZ information content (left figure, click to expand). Moreover, we show that combining the two probes leads to improved constraints on the ionization history when compared to individual constraints (right figure), and that working in the KL basis facilitates the detection of systematics and outliers.
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Global 21-cm Workshop talkRead more
Phys. Rev. D 105, 083503 [arXiv]Instrumentation for the ALBATROS experiment
In the past century, significant efforts have been made to map the sky at radio frequencies. Although a number of experiments operating below 100 MHz have shed light on the low frequency sky, there is a dearth of observational data below 30 MHz. Measuring the redshifted 21cm line at these frequencies is a promising avenue for probing the “Cosmic Dark Ages”, the epoch of the universe before the first stars and galaxies formed. Before we can measure the cosmological 21cm line at these frequencies, though, we need to understand the foreground contaminants which are orders of magnitude brighter! ALBATROS is an interferometric experiment aiming to produce high-quality maps of the sky below 30 MHz, thus paving the way for measurements of the Dark Ages. During my time working for the collaboration, I worked on the development of the first low-noise amplifier and antenna custom made for ALBATROS. I also designed a housing structure for the experiment's power systems, and took part in three remote deployments to set up the first fully autonomous ALBATROS antenna stations.
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SAZERAC talk
