Direct detection of CO(3-2) at z=7.31 in REBELS-25 gives M_mol ~ 10^11 M_sun with f_gas ~0.95, confirming a massive molecular reservoir and showing low-J CO remains detectable in the Epoch of Reionization.
Hidden in plain sight: a massive, dusty starburst in a galaxy protocluster at z=5.7 in the COSMOS field
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
We report the serendipitous discovery of a dusty, starbursting galaxy at $z=5.667$ (hereafter called CRLE) in close physical association with the "normal" main-sequence galaxy HZ10 at $z=5.654$. CRLE was identified by detection of [CII], [NII] and CO(2-1) line emission, making it the highest redshift, most luminous starburst in the COSMOS field. This massive, dusty galaxy appears to be forming stars at a rate of at least 1500$\,M_\odot$ yr$^{-1}$ in a compact region only $\sim3$ kpc in diameter. The dynamical and dust emission properties of CRLE suggest an ongoing merger driving the starburst, in a potentially intermediate stage relative to other known dusty galaxies at the same epoch. The ratio of [CII] to [NII] may suggest that an important ($\sim15\%$) contribution to the [CII] emission comes from a diffuse ionized gas component, which could be more extended than the dense, starbursting gas. CRLE appears to be located in a significant galaxy overdensity at the same redshift, potentially associated with a large-scale cosmic structure recently identified in a Lyman Alpha Emitter survey. This overdensity suggests that CRLE and HZ10 reside in a protocluster environment, offering the tantalizing opportunity to study the effect of a massive starburst on protocluster star formation. Our findings support the interpretation that a significant fraction of the earliest galaxy formation may occur from the inside out, within the central regions of the most massive halos, while rapidly evolving into the massive galaxy clusters observed in the local Universe.
fields
astro-ph.GA 2years
2026 2verdicts
UNVERDICTED 2representative citing papers
Simulations from COSMOS2020 show masking recovers [CII] above 300 GHz in ideal conditions but noise prevents useful S/N until near the end of 2000-hour observations.
citing papers explorer
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Direct detection of cool molecular gas in a star-forming galaxy at $z=7.31$
Direct detection of CO(3-2) at z=7.31 in REBELS-25 gives M_mol ~ 10^11 M_sun with f_gas ~0.95, confirming a massive molecular reservoir and showing low-J CO remains detectable in the Epoch of Reionization.
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Testing masking effectiveness using multi-line image cubes based on COSMOS2020 for [CII] line intensity mapping at $z_{[CII]} > 3.5$
Simulations from COSMOS2020 show masking recovers [CII] above 300 GHz in ideal conditions but noise prevents useful S/N until near the end of 2000-hour observations.