Witnessing the Birth of the Red Sequence: ALMA High-resolution Imaging of [C II] and Dust in Two Interacting Ultra-red Starbursts at z = 4.425

Oteo, I.; Ivison, R.J.; Dunne, L.; Smail, I.; Swinbank, A.M.; Zhang, Z.-Y.; Lewis, A.; Maddox, S.; Riechers, D.; Serjeant, S.; Van der Werf, P.; Biggs, A.D.; Bremer, M.; Cigan, P.; Clements, D.L.; Cooray, A.; Dannerbauer, H.; Eales, S.; Ibar, E.; Messias, H.; Michałowski, M.J.; Pérez-Fournon, I.; van Kampen, E.

doi:10.3847/0004-637x/827/1/34

Witnessing the Birth of the Red Sequence: ALMA High-resolution Imaging of [C II] and Dust in Two Interacting Ultra-red Starbursts at z = 4.425

Oteo, I.; Ivison, R.J.; Dunne, L.; Smail, I.; Swinbank, A.M.; Zhang, Z.-Y.; Lewis, A.; Maddox, S.; Riechers, D.; Serjeant, S.; Van der Werf, P.; Biggs, A.D.; Bremer, M.; Cigan, P.; Clements, D.L.; Cooray, A.; Dannerbauer, H.; Eales, S.; Ibar, E.; Messias, H.; Michałowski, M.J.; Pérez-Fournon, I.; van Kampen, E.

Authors

I. Oteo

R.J. Ivison

L. Dunne

Professor Ian Smail ian.smail@durham.ac.uk
Emeritus Professor

Professor Mark Swinbank a.m.swinbank@durham.ac.uk
Professor

Z.-Y. Zhang

A. Lewis

S. Maddox

D. Riechers

S. Serjeant

P. Van der Werf

A.D. Biggs

M. Bremer

P. Cigan

D.L. Clements

A. Cooray

H. Dannerbauer

S. Eales

E. Ibar

H. Messias

M.J. Michałowski

I. Pérez-Fournon

E. van Kampen

Abstract

Exploiting the sensitivity and spatial resolution of the Atacama Large Millimeter/submillimeter Array, we have studied the morphology and the physical scale of the interstellar medium—both gas and dust—in SGP 38326, an unlensed pair of interacting starbursts at z = 4.425. SGP 38326 is the most luminous star bursting system known at z > 4, with a total IR luminosity of L IR ~ 2.5 × 1013 L ⊙ and a star formation rate of ~ 4500 M ⊙ yr−1. SGP 38326 also contains a molecular gas reservoir among the most massive yet found in the early universe, and it is the likely progenitor of a massive, red-and-dead elliptical galaxy at z ~ 3. Probing scales of ~0farcs1 or ~800 pc we find that the smooth distribution of the continuum emission from cool dust grains contrasts with the more irregular morphology of the gas, as traced by the [C ii] fine structure emission. The gas is also extended over larger physical scales than the dust. The velocity information provided by the resolved [C ii] emission reveals that the dynamics of the two interacting components of SGP 38326 are each compatible with disk-like, ordered rotation, but also reveals an ISM which is turbulent and unstable. Our observations support a scenario where at least a subset of the most distant extreme starbursts are highly dissipative mergers of gas-rich galaxies.

Citation

Oteo, I., Ivison, R., Dunne, L., Smail, I., Swinbank, A., Zhang, Z., …van Kampen, E. (2016). Witnessing the Birth of the Red Sequence: ALMA High-resolution Imaging of [C II] and Dust in Two Interacting Ultra-red Starbursts at z = 4.425. Astrophysical Journal, 827(1), Article 34. https://doi.org/10.3847/0004-637x/827/1/34

Journal Article Type	Article
Acceptance Date	Jun 13, 2016
Online Publication Date	Aug 4, 2016
Publication Date	Aug 4, 2016
Deposit Date	Nov 7, 2016
Publicly Available Date	Nov 10, 2016
Journal	Astrophysical Journal
Print ISSN	0004-637X
Electronic ISSN	1538-4357
Publisher	American Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	827
Issue	1
Article Number	34
DOI	https://doi.org/10.3847/0004-637x/827/1/34