Roman CCS White Paper Opportunities for galaxy – 21-cm cross-correlations at high redshifts

Roman CCS White Paper — Cover Page

LIMFAST. V. Probing Reionization with the Synergy Between 21 cm and Photometric Galaxy Surveys

Cross-correlating the 21\,cm signal from intergalactic neutral hydrogen with the galaxy distribution is a powerful probe of the Epoch of Reionization and the physical mechanisms driving it. While upcoming surveys with the SKA-Low radio telescope and the Roman Space Telescope offer ideal synergies for this measurement,...

Two Exciting High-redshift Galaxy Candidates Turn Out to Be Two Exciting Brown Dwarfs

From the onset of observations of JWST we have discovered unexpectedly luminous galaxies at redshifts z > 10 and as high as z = 14. With their discovery, the question immediately followed as to where their progenitors are, since such progenitors should be within reach of existing surveys. However, the discovery of seve...

Using Supernovae to find faint galaxies in the High Latitude Time Domain Survey: An Appeal to “save the pixels” After a Supernova

Cosmic Noon Galaxies in the Hubble Ultra Deep Field with MIRI Wide-Field Slitless Spectroscopy

We present results from a survey of the Hubble Ultra-Deep Field using the Wide-Field Slitless Spectroscopic (WFSS) capability of the Mid-Infrared Instrument (MIRI) on JWST, demonstrating the capabilities of this new mode. We describe the data reduction and calibration methodology, and estimate calibration uncertainties...

One cloud is not enough: Extreme conditions biasing chemical abundances in high-redshift galaxies

Since its launch, JWST has enabled the characterisation of the ionised interstellar medium (ISM) of high-redshift galaxies using a range of rest-frame ultraviolet (UV) and optical diagnostics originally developed in the Local Universe. These observations challenge the validity of such classical methods in extreme high-...