Bright [CII]158$μ$m Streamers as a Beacon for Giant Galaxy Formation in SPT2349$-$56 at $z=4.3$
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| Název: | Bright [CII]158$μ$m Streamers as a Beacon for Giant Galaxy Formation in SPT2349$-$56 at $z=4.3$ |
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| Autoři: | Sulzenauer, Nikolaus, Weiß, Axel, Hill, Ryley, Chapman, Scott C., Aravena, Manuel, Dike, Veronica J., Gonzalez, Anthony, MacIntyre, Duncan, Narayanan, Desika, Phadke, Kedar A., Pillai, Vismaya R., Posses, Ana C., Rennehan, Douglas, Saintonge, Amelie, Spilker, Justin S., Solimano, Manuel, Tsuchitori, Joel, Vieira, Joaquin D., Vizgan, David, Zhou, Dazhi |
| Publication Status: | Preprint |
| Informace o vydavateli: | arXiv, 2025. |
| Rok vydání: | 2025 |
| Témata: | Astrophysics of Galaxies, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences |
| Popis: | Observations of extreme starbursts, often located in the cores of protoclusters, challenge the classical bottom-up galaxy formation paradigm. Giant elliptical galaxies at $z=0$ must have assembled rapidly, possibly within few 100 Myr through an extreme growth phase at high-redshift, characterized by elevated star-formation rates of several thousand solar masses per year distributed over concurrent, gas-rich mergers. We present a novel view of the $z=4.3$ protocluster core SPT2349$-$56 from sensitive multi-cycle ALMA dust continuum and [CII]158$μ$m line observations. Distributed across 60 kpc, a highly structured gas reservoir with a line luminosity of $L_\mathrm{[CII]}=3.0\pm0.2\times10^9$ $L_\odot$ and an inferred cold gas mass of $M_{gas}= 8.9\pm0.7\times10^{9}$ $M_\odot$ is found surrounding the central massive galaxy triplet. Like ``beads on a string'', the newly-discovered [CII] streamers fragment into a few kpc-spaced and turbulent clumps that have a similar column density as local Universe spiral galaxy arms at $Σ_{gas}=20$--$60$ $M_\odot$ pc$^{-2}$. For a dust temperature of 30 K, the [CII] emission from the ejected clumps carry $\gtrsim$3% of the FIR luminosity, translating into an exceptionally low mass-to-light ratio of $α_\mathrm{[CII]}=2.95\pm0.3$ $M_\odot$ $L_\odot^{-1}$, indicative of shock-heated molecular gas. In phase space, about half of the galaxies in the protocluster core populate the same caustic as the [CII] streamers ($r/r_{vir}\times|Δv|/σ_{vir}\approx0.1$), suggesting angular momentum dissipation via tidal ejection while the brightest cluster galaxy (BCG) is assembling. Our findings provide new evidence for the importance of tidal ejections of [CII]-bright, shocked material following multiple major mergers that might represent a landmark phase in the $z\gtrsim4$ co-evolution of BCGs with their hot, metal enriched atmospheres. 31 pages, 12 figures, 5 tables. Submitted to ApJ |
| Druh dokumentu: | Article |
| DOI: | 10.48550/arxiv.2509.08035 |
| Přístupová URL adresa: | http://arxiv.org/abs/2509.08035 |
| Rights: | CC BY |
| Přístupové číslo: | edsair.doi.dedup.....57a8d79a9c43e4fafb7f4b187e5ddd5c |
| Databáze: | OpenAIRE |
Nájsť tento článok vo Web of Science | Abstrakt: | Observations of extreme starbursts, often located in the cores of protoclusters, challenge the classical bottom-up galaxy formation paradigm. Giant elliptical galaxies at $z=0$ must have assembled rapidly, possibly within few 100 Myr through an extreme growth phase at high-redshift, characterized by elevated star-formation rates of several thousand solar masses per year distributed over concurrent, gas-rich mergers. We present a novel view of the $z=4.3$ protocluster core SPT2349$-$56 from sensitive multi-cycle ALMA dust continuum and [CII]158$μ$m line observations. Distributed across 60 kpc, a highly structured gas reservoir with a line luminosity of $L_\mathrm{[CII]}=3.0\pm0.2\times10^9$ $L_\odot$ and an inferred cold gas mass of $M_{gas}= 8.9\pm0.7\times10^{9}$ $M_\odot$ is found surrounding the central massive galaxy triplet. Like ``beads on a string'', the newly-discovered [CII] streamers fragment into a few kpc-spaced and turbulent clumps that have a similar column density as local Universe spiral galaxy arms at $Σ_{gas}=20$--$60$ $M_\odot$ pc$^{-2}$. For a dust temperature of 30 K, the [CII] emission from the ejected clumps carry $\gtrsim$3% of the FIR luminosity, translating into an exceptionally low mass-to-light ratio of $α_\mathrm{[CII]}=2.95\pm0.3$ $M_\odot$ $L_\odot^{-1}$, indicative of shock-heated molecular gas. In phase space, about half of the galaxies in the protocluster core populate the same caustic as the [CII] streamers ($r/r_{vir}\times|Δv|/σ_{vir}\approx0.1$), suggesting angular momentum dissipation via tidal ejection while the brightest cluster galaxy (BCG) is assembling. Our findings provide new evidence for the importance of tidal ejections of [CII]-bright, shocked material following multiple major mergers that might represent a landmark phase in the $z\gtrsim4$ co-evolution of BCGs with their hot, metal enriched atmospheres.<br />31 pages, 12 figures, 5 tables. Submitted to ApJ |
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| DOI: | 10.48550/arxiv.2509.08035 |