Hubble Finds 1 Galaxy Clearing Gas 1.4 Billion Years After Big Bang
Updated
Updated · TechEBlog · Jun 24
Hubble Finds 1 Galaxy Clearing Gas 1.4 Billion Years After Big Bang
3 articles · Updated · TechEBlog · Jun 24
Summary
MXDFz4.4, seen as it was 1.4 billion years after the Big Bang, is the first individual galaxy shown directly to clear opaque hydrogen gas around itself.
50% to 100% of its ionizing ultraviolet light appears to have escaped because tight bursts of star formation packed the tiny galaxy with massive, short-lived stars that blasted holes in surrounding gas.
Hubble identified the concentrated young star clusters behind that escape, while Webb measured the galaxy’s mass and older stars and the VLT fixed its distance in the MUSE eXtremely Deep Field.
Roughly 100 times smaller in area than the Milky Way but forming stars about 10 times faster, MXDFz4.4 pushes direct evidence of this process earlier than prior detections at about 1.6 billion years after the Big Bang.
This tiny galaxy cleared its local fog. But what truly lifted the cosmic curtain across the entire early universe?
Is this record-breaking galaxy a rare pioneer, or just the first of many faint cosmic lighthouses we've found?
MXDFz4.4’s Escaping Ultraviolet Light: Direct Evidence for Cosmic Reionization and Early Galaxy Evolution
Overview
Astronomers used NASA’s Hubble Space Telescope to detect ultraviolet light escaping from the distant galaxy MXDFz4.4, which contains tightly clustered young stars. These stars produce powerful ionizing light that transforms the neutral gas around the galaxy, clearing a path for the light to escape. This direct observation provides strong evidence that similar galaxies in the early universe played a key role in changing the cosmos from an opaque, neutral state to a transparent, ionized one, advancing our understanding of the Era of Reionization and how the universe became visible.