Improved upper limits on the 21-cm signal power spectrum of neutral hydrogen at $\mathbf{z}\approx 9.1$ from LOFAR

F. G. Mertens, M. Mevius, L. V. E Koopmans +23

A new upper limit on the 21-cm signal power spectrum at a redshift of $z\approx 9.1$ is presented, based on 141 hours of data obtained with the Low-Frequency Array (LOFAR). The an…