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Abstract We report the detection of 23 OH + 1 → 0 absorption, emission, or P-Cygni-shaped lines and CO( J = 9→8) emission lines in 18 Herschel-selected z = 2–6 starburst galaxies with the Atacama Large Millimeter/submillimeter Array and the NOrthern Extended Millimeter Array, taken as part of the Gas And Dust Over cosmic Time Galaxy Survey. We find that the CO( J = 9→8) luminosity is higher than expected based on the far-infrared luminosity when compared to nearby star-forming galaxies. Together with the strength of the OH + emission components, this may suggest that shock excitation of warm, dense molecular gas is more prevalent in distant massive dusty starbursts than in nearby star-forming galaxies on average, perhaps due to an impact of galactic winds on the gas. OH + absorption is found to be ubiquitous in massive high-redshift starbursts, and is detected toward 89% of the sample. The majority of the sample shows evidence for outflows or inflows based on the velocity shifts of the OH + absorption/emission, with a comparable occurrence rate of both at the resolution of our observations. A small subsample appears to show outflow velocities in excess of their escape velocities. Thus, starburst-driven feedback appears to be important in the evolution of massive galaxies in their most active phases. We find a correlation between the OH + absorption optical depth and the dust temperature, which may suggest that warmer starbursts are more compact and have higher cosmic-ray energy densities, leading to more efficient OH + ion production. This is in agreement with a picture in which these high-redshift galaxies are “scaled-up” versions of the most intense nearby starbursts.
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This content will become publicly available on July 28, 2026
Shockingly Effective: Cluster Winds as Engines of Feedback in Starburst Galaxy VV 114
Abstract We present high-resolution Keck Cosmic Web Imager and MUSE integral field unit spectroscopy of VV 114, a local IR-luminous merger undergoing a vigorous starburst and showing evidence of galactic-scale feedback. The high-resolution data allow for spectral deblending of the optical emission lines and reveal a broad emission line component (σbroad ∼ 100–300 km s−1) with line ratios and kinematics consistent with a mixture of ionization by stars and radiative shocks. The shock fraction (percentage of ionization due to shocks) in the high-velocity gas is anticorrelated with the projected surface number density of resolved star clusters, and we find that the radial density profiles around clusters are fit well by models of adiabatically expanding cluster winds driven by massive stellar winds and supernovae (SNe). The total kinetic power estimated from the cluster wind models matches the wind + SN mechanical energy deposition rate estimated from the soft-band X-ray luminosity, indicating that at least 70% of the shock luminosity in the galaxy is driven by the star clusters. Hubble Space Telescope narrowband near-IR imaging reveals embedded shocks in the dust-buried IR nucleus of VV 114E. Most of the shocked gas is blueshifted with respect to the quiescent medium, and there is a close spatial correspondence between the shock map and the Chandra soft-band X-ray image, implying the presence of a galactic superwind. The energy budget of the superwind is in close agreement with the total kinetic power of the cluster winds, confirming the superwind is driven by the starburst.
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- PAR ID:
- 10626642
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Publisher / Repository:
- IOP Publishing
- Date Published:
- Journal Name:
- The Astrophysical Journal
- Volume:
- 988
- Issue:
- 2
- ISSN:
- 0004-637X
- Page Range / eLocation ID:
- 230
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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