Stellar feedback as the origin of an extended molecular outflow in a starburst galaxy

Abstract

Recent observations have revealed that starburst galaxies can drive molecular gas outflows through stellar radiation pressure. Molecular gas is the phase of the interstellar medium from which stars form, so these outflows curtail stellar mass growth in galaxies. Previously known outflows, however, involve small fractions of the total molecular gas content and are restricted to sub-kiloparsec scales. It is also apparent that input from active galactic nuclei is in at least some cases dynamically important, so pure stellar feedback has been considered incapable of aggressively terminating star formation on galactic scales. Extraplanar molecular gas has been detected in the archetype starburst galaxy M82, but so far there has been no evidence that starbursts can propel significant quantities of cold molecular gas to the same galactocentric radius (~10 kpc) as the warmer gas traced by metal absorbers. Here we report observations of molecular gas in a compact (effective radius 100 pc) massive starburst galaxy at z=0.7, which is known to drive a fast outflow of ionized gas. We find that 35 per cent of the total molecular gas is spatially extended on a scale of approximately 10 kpc, and one third of this has a velocity of up to 1000 km/s. The kinetic energy associated with this high-velocity component is consistent with the momentum flux available from stellar radiation pressure. This result demonstrates that nuclear bursts of star formation are capable of ejecting large amounts of cold gas from the central regions of galaxies, thereby strongly affecting their evolution.

Published in Nature, December 4 (volume 516; issue 7529; pp 68-70). This is the author's version of the paper, including Methods. Link to accepted, published version: http://dx.doi.org/10.1038/nature14012

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Cited by in corpus (9)

• Dynamics of Dusty Radiation Pressure Driven Shells and Clouds: Fast Outflows from Galaxies, Star Clusters, Massive Stars, and AGN
• PHIBSS2: survey design and z=0.5-0.8 results. Molecular gas reservoirs during the winding-down of star formation
• A Review of Recent Observations of Galactic Winds Driven by Star Formation
• Feedback in low-mass galaxies in the early Universe
• From outside-in to inside-out: galaxy assembly mode depends on stellar mass
• Massive outflow properties suggest AGN fade slowly
• Evolution of Molecular Clouds in the Superwind Galaxy NGC 1808 Probed by ALMA Observations
• The growth of typical star-forming galaxies and their super massive black holes across cosmic time since z~2
• The inflow and outflow rate evolution of local Milky Way-mass star-forming galaxies since z=1.3