A direct detection of neutral hydrogen intensity mapping on Mpc scales at $z\approx 0.32$ and $z\approx 0.44$

Understand

We report the detection of the cosmological power spectrum using the intensity mapping signal from 21-cm emission of neutral hydrogen (HI), derived from interferometric observations with the L-band receivers of the MeerKAT radio telescope.

• Intensity mapping is a promising technique to map the three-dimensional matter distribution of the Universe at radio frequencies and probe the underlying Cosmology.
• So far, detections have only been achieved through cross-correlations with galaxy surveys.
• Here we present independent measurements of the HI power spectrum at redshifts $0.32$ and $0.44$ with the foreground avoidance method.