Astronomy & Astrophysics

University of California, Santa Cruz

1156 High St.
Santa Cruz, CA  95064

Tel:  (831) 459-1637

Fax:  (831) 459-5717

ammons [at] ucolick [dot] org

I am investigating the optical/NIR photometric properties and kinematic irregularities of AGN hosts locally and at z~1.  In collaboration with the Center for Adaptive Optics Treasury Survey (CATS, co-PIs Max, Koo, Larkin), I combine HST ACS imagery with Keck Laser Guide Star AO K', VLT ISAAC Ks, and NICMOS H images.  Using this multicolor photometry at ~300-500 pc rest-frame resolution, we can constrain the stellar populations independent of dust extinction of AGN hosts at z~1.  I find that intermediate luminosity X-ray-selected AGN hosts in GOODS-South (43 < log Lx < 44) tend to have more young (< 100 Myr) stars than AGN hosts with weaker X-ray luminosity.

With graduate student Anne Medling, we are using Laser Guide Star AO to resolve the kinematic signatures of stellar Keplerian orbits about a central black hole in the famous merger NGC6240.  Using the near-IR to penetrate the dusty obscuring media in this dual AGN, we find a southern black hole mass of ~3-5 billion solar masses. 

I research technologies that will enable diffraction-limited imaging and spectroscopy over a wide-field (1-2') at visible wavelengths (500-700 nm) on 5-10 meter class telescopes with excellent sky coverage.  I have used the Laboratory for Adaptive Optics MCAO/MOAO testbed to obtain good R-band Strehls (20%) over a 45" field on a 10-meter telescope, using a multi-LGS, tomographic MOAO architecture.  

Our team has installed a visible light AO system on the 1-meter Nickel telescope at Lick Observatory to prove several enabling technologies on-sky, including (1) MEMS deformable mirror operation, (2) open-loop operation of wavefront sensors, and (3) use of uplink LGS correction to lower total required laser power.