Global 21 cm signal experiments: A designer’s guide

Global 21 cm signal experiments : A designer ’ s guide

Chromatic effects in the 21 cm global signal from the cosmic dawn

The redshifted 21 cm brightness distribution from neutral hydrogen is a promising probe into the cosmic dark ages, cosmic dawn, and re-ionization. LOFAR’s Low Band Antennas (LBA) may be used in the frequency range 45 MHz to 85 MHz (30 > z > 16) to measure the sky averaged redshifted 21 cm brightness temperature as a function of frequency, or equivalently, cosmic redshift. These low frequencies ...

The global 21-cm signal in the context of the high-z galaxy luminosity function

We build a new model for the global 21-cm signal that is calibrated to measurements of the high-z galaxy luminosity function (LF) and further tuned to match the Thomson scattering optical depth of the cosmic microwave background, τ e. Assuming that the z 8 galaxy population can be smoothly extrapolated to higher redshifts, the recent decline in best-fitting values of τ e and the inefficient hea...

COSMIC REIONIZATION AND THE 21 cm SIGNAL: COMPARISON BETWEEN AN ANALYTICAL MODEL AND A SIMULATION

We measure several properties of the reionization process and the corresponding low-frequency 21 cm signal associated with the neutral hydrogen distribution, using a large volume, high-resolution simulation of cosmic reionization. The brightness temperature of the 21 cm signal is derived by postprocessing this numerical simulationwith a semianalytical prescription. Our study extends to high red...

How well can we measure and understand foregrounds with 21 cm experiments?

Before it becomes a sensitive probe of the Epoch of Reionization, the Dark Ages, and fundamental physics, 21 cm tomography must successfully contend with the issue of foreground contamination. Broadband foreground sources are expected to be roughly four orders of magnitude larger than any cosmological signals, so precise foreground models will be necessary. Such foreground models often contain ...