Lyman-α emitting galaxy EGSY8p7 in the CEERS survey field (NIRCam image)

This image shows the galaxy EGSY8p7, a bright galaxy in the early Universe where light emission is seen from, among other things, excited hydrogen atoms — Lyman-α emission. The galaxy was identified in a field of young galaxies studied by Webb in the CEERS survey. In the bottom two panels, Webb’s high sensitivity picks out this distant galaxy along with its two companion galaxies, where previous observations saw only one larger galaxy in its place.

This discovery of a cluster of interacting galaxies sheds light on the mystery of why the hydrogen emission from EGSY8p7, shrouded in neutral gas formed after the Big Bang, should be visible at all. Astronomers have concluded that the intense star-forming activity within these interacting galaxies energised hydrogen emission and cleared swathes of gas from their surroundings, allowing the unexpected hydrogen emission to escape.

This graphic is assembled from multiple images captured by Webb’s NIRCam instrument as part of the CEERS survey. The close-up view of EGSY8p7 was newly processed for this image, making use of NIRCam data captured with seven different near-infrared filters.

[Image Description: A graphic with three images. The top image, labelled “CEERS survey”, shows many square images of stars and galaxies, stitched together according to their locations in the sky. One square is highlighted, and a cutout on the bottom left shows it enlarged, labelled “Webb/ NIRCam”. A tiny spot is shown zoomed-in to the right, labelled “EGSY8p7” with a scale marker of “0.5 arcsec”. Here it can be seen that the spot is three neighbouring galaxies, appearing as coloured blobs with bright, distinct cores.]

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