research
A Dark-Galaxy Candidate Appeared Without Starlight
FAST found compact hydrogen, but deep optical imaging found no counterpart down to a faint surface-brightness limit.
Summary
FAST found compact hydrogen, but deep optical imaging found no counterpart down to a faint surface-brightness limit.
A blind FAST hydrogen survey and DESI Legacy Survey imaging identified J1351+0039 as an isolated Reionization-Limited H I Cloud candidate. The object has an inferred neutral-hydrogen mass of 480,000 solar masses, no detected optical counterpart to a g-band surface-brightness limit of 28.1 magnitudes per square arcsecond, and an estimated dynamical mass of 130 million solar masses. The authors derive a dark-to-baryonic mass ratio near 200, while describing the classification as a promising candidate rather than a settled dark-galaxy discovery.
Why it matters
FAST found compact hydrogen, but deep optical imaging found no counterpart down to a faint surface-brightness limit.
Limits and context
No additional limitation was separately recorded.
Key claims
FAST found compact hydrogen, but deep optical imaging found no counterpart down to a faint surface-brightness limit.
Evidence: source-2026-09-25-006
Sources
- arXiv preprint 2609.29852arXiv · primary research
Corrections
No corrections have been recorded for this story.