Search Publications

Gravitational lensing reveals ionizing ultraviolet photons escaping from a distant galaxy

Mahler, Guillaume; Chisholm, John; Rigby, Jane R. +7 more

During the epoch of reionization, neutral gas in the early Universe was ionized by hard ultraviolet radiation emitted by young stars in the first galaxies. To do so, ionizing ultraviolet photons must escape from the host galaxy. We present Hubble Space Telescope observations of the gravitationally lensed post-reionization galaxy PSZ1-ARC G311.6602…

A measurement of the Hubble constant from angular diameter distances to two gravitational lenses

Fassnacht, Christopher D.; Hilbert, Stefan; Suyu, Sherry H. +3 more

The local expansion rate of the Universe is parametrized by the Hubble constant, H0, the ratio between recession velocity and distance. Different techniques lead to inconsistent estimates of H0. Observations of Type Ia supernovae (SNe) can be used to measure H0, but this requires an external calibrator to convert relative distances to absolute one…