David Koo's Home Page 

UCO/Lick Observatory
University of California, Santa Cruz
1156 High Street
Santa Cruz, CA 95064

Latest Modification:  TARGET - 2017 May 1

  Background (Under Construction):

I was faculty (Astronomer and Professor) at the University of California, Santa Cruz from 1988 until summer 2014 when I retired.  

  Research (Under Construction):

 I continue to enjoy  research in astrophysics with my long-term  colleague and collaborator, Sandy Faber, at UC Santa Cruz.   DEEP has been my major umbrella research program involving Keck spectral observations of faint galaxies. This program is in its 3rd decade.  DEEP started in the mid-1990's with the inception of the Keck I telescope with several pilot redshift surveys, known as DEEP1, totaling over 1000 galaxies to I ~ 24 with exposures ranging up to several hours.  The follow-up and main phase of DEEP , called DEEP2,  was started in 2002 and finished by 2008.  DEEP2  used over 90  Keck nights with a  powerful instrument built by Sandy (DEIMOS) to secure  spectra of 1 hour exposures of over 50,000 galaxies to R ~ 24.1 at redshifts z ~ 1. Such a large sample is needed to probe the large scale structure of galaxies and unravel the details and physical mechanisms involved in galaxy formation and evolution.  In one of the 4 regions of the DEEP2 survey,  known as the Extended Groth Strip (EGS), a consortium of teams  known as AEGIS, has added a suite of deep to very deep panchromatic data ranging from the X-rays to radio. These data allow powerful probes of distant Active Galactic Nuclei (AGN) with supermassive black holes,  as well as luminous, dusty starburst galaxies. In this EGS region, another 5,000 galaxies were observed with DEIMOS as part of DEEP3 and completed in 2011. DEEP3 differed from DEEP2 by extending to the blue but reducing the spectral resolution. The sample was also more focused on special targets such as AGNs and pushed beyond R ~ 24.

Our  multi-wavelength research as part of AEGIS has expanded over the years and now  include 4 of the other best observed fields for faint multi-wavelength extragalactic research: GOODS-North and GOODS-South, an  UltraVISTA portion of COSMOS, and the central part of the UKIDSS Ultra-Deep Survey (UDS) fields.  Several surveys have solidified these 5 as among the very best legacy fields for the foreseeable future: two  led by G. Fazio (CfA)  gathered over 2100 hours of Spitzer IRAC data (SEDS; S-CANDELS);  some were deep HST WFC3 grism surveys led by Weiner for GOODS-North van Dokkum (Yale) for the other 4 fields; several have been the deepest Chandra X-ray maps, led by K. Nandra (MPI) for AEGIS-X and G. Hasinger (IoA-Hawaii) for X-UDS; and most important of all and  completed in August 2013, a 902 orbit survey led by S. Faber and H. Ferguson (STScI) using HST WFC3 near-IR and a 902 ACS images survey (CANDELS) as part of the HST Multi-cycle Treasury Program.

Our recent observations include follow-up multi-object near-infrared spectroscopy with the  MOSFIRE instrument on Keck  as well as pushing to much longer exposures of 8 hours or longer  of intermediate redshift z ~ 0.5 to 1.5 galaxies in the CANDELS fields using DEIMOS and the DEEP3 setup. The deeper DEIMOS spectra enable improved measures of galactic winds and kinematics and so these surveys are grouped under the name DEEPwinds, though most of the data are being collected in piggy-back mode of a Milky-Way halo star program known as HALO7D, led by our DEEP colleagues,  P. GuhathaKurta and C. Rockosi at UCSC. As of 2016 with the help of a Google gift, we have begun exploring the use of Deep Learning (machine learning based on convolutional neural networks) for analyzing both simulations and data with our colleague, Marc Huertas-Company, from the Observatoire de Paris.

  Recent Publications & CV:

Here is a link to my most recent 100 publications using ADS.  For refereed publications ordered from highest citations first (citation ordered).  Here is my latest CV.

  Postdoc Positions:

We filled one fully-supported postdoctoral position for  3 years starting fall 2016.  We expect no new such fully-supported openings for the forseeable future. We have and will continue to  host those with their own funding support.