CATS uses Keck Laser Guide Star adaptive optics to observe a large, deep sample of galaxies in the early Universe. The primary goal of this legacy program is to track the assembly of galaxies like our own Milky Way through their history of star formation. The near-IR AO observations are 4x sharper than seen by the Hubble Space Telescope and will not be excelled until the advent of larger (20-30m class) telescopes with AO being planned for the next decade. By observing in the GOODS, GEMS and EGS fields, the scientific value of the AO data is highly leveraged by the existing complementary deepest space-based images ever taken. We also expect serendipitous observations of supermassive black holes that are enshrouded by dust in the very early universe and of supernova explosions that can be used to measure the curvature and "dark energy" of the Universe.
We are using the excellent multi-mavelength data available in the Great Observatories Origins Deep Survey to track the optical and infrared evolution of blue galaxies since z=1. We find evidence for size dependent blue luminosity evolution among blue galaxies. This corresponds to a dimming of ~1.6 magnitudes since z=1 for galaxies with half-light radii larger than 2.5 kpc, and can be explained by a simple exponential decline the star formation rate. These results match well to star formation rate indicators from MIPS in the mid infrared. The MIPS data show a rapidly evolving population of luminous infrared galaxies (LIRGs) with very high star formation rates. Above z=0.5 LIRGs become relatively common and are primarily spiral galaxies. Below z=0.5 LIRGs are rare and become dominated by objects with peculiar or merger type morphology. The link allows you to browse through the optical and infrared measurements we made on the GOODS-N galaxies.
Blue Compact Galaxies (BCGs) are a subset of H II galaxies with small physical sizes, low metal abundances, and are comprised of one or more intense starbursting knots. These systems are found at local to intermediate redshifts and at z = 1 make up 10% of the observed galaxies. As a result of their unusual properties several major questions arise. Is there a population of truly young local BCGs or are older stellar populations hiding under the starbursts? What triggers a starburst event? What do BCGs eventually evolve into? We propose a pilot study to do high spatial resolution NIR imaging and spectroscopy of nearby BCGs with the Lick 3m Adaptive Optics (AO) system. We have three objectives. First, the high spatial resolution J, H and K imaging, achievable with AO, is necessary to resolve each galaxy into separate star-forming knots and identify the older stellar components. Second, spatially resolved grism spectroscopy will reveal the ionization sources and the internal kinematics of the galaxy. This may provide insight into triggers for the starburst event. Third, we will use these data to address the effects of AO on measured photometry and line flux. This will lay the ground work for an expanded study of merging and starbursting galaxies out to z=1 which will soon be possible with AO fed spectrographs and Integral Field Units on 10m class telescopes.
The KPNO
International Spectroscopic Survey (KISS) is a wide
field objective prism survey which utilizes the KPNO
Burrell Schmidt telescope
with a 2048 x 2048 CCD detector. The survey detects strong-lined
emission line galaxies (ELGs) with continuum magnitudes down to B = 20
and redshifts out to z = 0.1. KISS extends previous objective prism
surveys by going 2-3 magnitudes deeper yet still covering a large
area on the sky. I measure metal abundances of the ELGs from
follow-up spectra using both strong line and nebular abundance methods.
