A subarcsecond near-infrared view of massive galaxies at z > 1 with Gemini Multiconjugate Adaptive Optics

Journal article

We present images taken using the Gemini South Adaptive Optics Imager (GSAOI) with the Gemini Multiconjugate Adaptive Optics System (GeMS) in three 2 arcmin$^2$ fields in the Spitzer Extragalactic Representative Volume Survey. These GeMS/GSAOI observations are among the first $\approx 0.1^{''}$ resolution data in the near-infrared spanning extragalactic fields exceeding $1.5^{\prime}$ in size. We use these data to estimate galaxy sizes, obtaining results similar to those from studies with the Hubble Space Telescope, though we find a higher fraction of compact star forming galaxies at $z>2$. To disentangle the star-forming galaxies from active galactic nuclei (AGN), we use multiwavelength data from surveys in the optical and infrared, including far-infrared data from Herschel, as well as new radio continuum data from the Australia Telescope Compact Array and Very Large Array. We identify ultraluminous infrared galaxies (ULIRGs) at $z \sim 1-3$, which consist of a combination of pure starburst galaxies and Active Galactic Nuclei (AGN)/starburst composites. The ULIRGs show signs of recent merger activity, such as highly disturbed morphologies and include a rare candidate triple AGN. We find that AGN tend to reside in hosts with smaller scale sizes than purely star-forming galaxies of similar infrared luminosity. Our observations demonstrate the potential for MCAO to complement the deeper galaxy surveys to be made with the James Webb Space Telescope.

Authors: Lacy, M; Nyland, K; Mao, M; Jagannathan, P; Pforr, J

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Institute of Physics
• Journal: Astrophysical Journal
• Volume: 864
• Issue: 1
• Pages: 8
• Publication date: 2018-08-24
• Acceptance date: 2018-07-03
• DOI: 10.3847/1538-4357/aad27d
• Keywords: galaxies: evolution