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arXiv · 0911.3666

Revealing an Energetic Galaxy-Wide Outflow in a z~2 Ultraluminous Infrared Galaxy

D. M. Alexander·A. M. Swinbank·I. Smail·R. McDermid·N. P. H. Nesvadba
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Abstract

Leading models of galaxy formation require large-scale energetic outflows to regulate the growth of distant galaxies and their central black holes. However, current observational support for this hypothesis at high redshift is mostly limited to rare z>2 radio galaxies. Here we present Gemini-North NIFS Intregral Field Unit (IFU) observations of the [O III]5007 emission from a z~2 ultraluminous infrared galaxy (ULIRG; L_IR>10^12 L_sol) with an optically identified Active Galactic Nucleus (AGN). The spatial extent (~4-8 kpc) of the high velocity and broad [O III] emission are consistent with that found in z>2 radio galaxies, indicating the presence of a large-scale energetic outflow in a galaxy population potentially orders of magnitude more common than distant radio galaxies. The low radio luminosity of this system indicates that radio-bright jets are unlikely to be responsible for driving the outflow. However, the estimated energy input required to produce the large-scale outflow signatures (of order ~10^59 ergs over ~30 Myrs) could be delivered by a wind radiatively driven by the AGN and/or supernovae winds from intense star formation. The energy injection required to drive the outflow is comparable to the estimated binding energy of the galaxy spheroid, suggesting that it can have a significant impact on the evolution of the galaxy. We argue that the outflow observed in this system is likely to be comparatively typical of the high-redshift ULIRG population and discuss the implications of these observations for galaxy formation models.

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D. M. Alexander, A. M. Swinbank, I. Smail, R. McDermid, N. P. H. Nesvadba. 2009-11-18. Revealing an Energetic Galaxy-Wide Outflow in a z~2 Ultraluminous Infrared Galaxy. https://arxiv.org/abs/0911.3666

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