Dr. Anton M. Koekemoer

Hubble Space Telescope /
Space Telescope Science Institute (STScI)

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Professional Information

Welcome to Anton's homepage! I am a research astrophysicist with the Hubble Space Telescope at the Space Telescope Science Institute (located in Baltimore, MD, USA), and I have held a research position here since 1997. Previous experience and education include: At the Space Telescope Science Institute, my work includes maintaining the scientific productivity of the Hubble Space Telescope, and for some years I was the team lead in charge of one of the imaging cameras onboard Hubble (the 'NICMOS' Near-Infrared Camera and Multi-Object Spectrometer). More recently I have also been working on the James Webb Space Telescope (the successor to Hubble, planned for launch in a few years), as well as the Hubble Legacy Data Archives, and I carry out astrophysics research programs on my areas of interest which include the formation of galaxies and black holes in the early universe and their growth over cosmic time.

Research Interests:

I have also been in charge of creating all the Hubble imaging mosaics as part of my science role in the following large projects:

 

Current research publications (1994 - 2014):

 

Hubble Frontier Fields 2013-2014 (ongoing)

I am in charge of the Hubble imaging for the Hubble Frontier Fields project, where I am leading the Science Data Products team and have responsibility for all the calibration, processing, and production of final science-grade mosaic images of these fields, as well as their public distribution to the community via our Archive Pages.

The first Press release, which took place on 7 January 2014, presents the initial data relase of the first epoch of the cluster Abell 2744. The cluster acts as a gravitational `lens' to amplify the distant galaxies behind it, and we are observing this field to very deep limits (about 28-29th magnitude AB), so the amplification provided by the cluster therefore helps to reveal galaxies that may be intrinsically fainter even than those that had been previously discovered in the Ultra Deep Field. A total of 6 clusters, each with an accompanying `parallel field', are being observed as part of this program across a wide range of filters with ACS (F435W, F606W, F814W) and also WFC3/IR (F105W, F125W, F140W, F160W), yielding a legacy set of multi-wavelength scientific products for probing galaxy evolution and cluster physics up to the distant universe.

 

 

Hubble Ultra Deep Field 2012

I was in charge of the imaging for the Hubble Ultra Deep Field 2012 project, where I led the observations and created all the final images. The Press release presents the various images and other details about the program, after the public data release took place on 12 December 2012. This new image of the Hubble Ultra Deep Field is the deepest ever image of the sky at these wavelengths. By combining new data obtained by the UDF12 Team (PI. R. Ellis) with previous data obtained by the UDF09 Team (PI.: G. illingworth) as well as other Hubble programs (The CANDELS team, PI.: S. Faber and H. Ferguson, and the Supernova team, PI.: A. Riess), these new data enable us to use Hubble to probe to deeper cosmic epochs than ever before.

The overview reference papers for this survey are:

A. M. Koekemoer et al., 2013, Astrophysical Journal Supplement, 209, 3
R. S. Ellis et al., 2013, Astrophysical Journal Letters, 763, 7

 

Hubble Ultra Deep Field 2004

I was in charge of the imaging for the Hubble Space Telescope / Advanced Camera for Surveys (HST/ACS) 2004 Hubble Ultra Deep Field (UDF) project, where my role was to calibrate, combine and analyse the 800 ACS/WFC exposures to produce a set of final, cleaned "drizzled" images in each of the four filters.

The Press release presents the various images and other details about the program, after the public data release took place on 9 March 2004.

 

CANDELS: Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey

I am responsible for all the Hubble imaging for the CANDELS project, where I led the calibration and processing, and created all the final mosaic images. This project is designed to document the first third of galactic evolution from between redshifts 1.5 and 8, via deep imaging of more than 250,000 galaxies with WFC3/IR and ACS, as well as discovering Type Ia supernovae beyond redshift 1.5 in order to establish their accuracy as standard candles for cosmology. The survey targets five premier multi-wavelength sky regions; each has multi-wavelength data from Spitzer and other facilities plus extensive spectroscopy of the brighter galaxies. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies to faint limitsout to redshift 8. The first Press release presents initial discoveries from the program.

The overview reference papers for this survey are:

N. A. Grogin et al., 2011, Astrophysical Journal Supplement, 197, 35
A. M. Koekemoer et al., 2011, Astrophysical Journal Supplement, 197, 36

 

Hubble Wide Field Camera 3 / Early Release Science (WFC3 / ERS)

I was part of the team for the new Early Release Science Program obtained with the Hubble Space Telescope / Wide Field Camera 3 (HST/WFC3), which was installed on Hubble by the Astronauts during Servicing Mission 4 in May 2009. This program uses the new Wide Field Camera 3 to obtain extensive new, deep near-infrared data on the GOODS-South Field (part of the "Great Observatories Origins Deep Survey" / "GOODS" project). The Press release presents the various images and other details about the program, after the public release took place on 5 January 2010.

 

The Hubble COSMOS Survey

I was also in charge of combining all the Hubble imaging data for the COSMOS project, which used 600 orbits of Hubble time to produce the largest single mosaic ever obtained with HST (about 2 square degrees, or about 10 times the area of the full moon, and covering about 2 million galaxies); my science interest in this project is to search for supermassive black holes in the very early universe.

The overview reference papers for the COSMOS HST data are:

A. M. Koekemoer et al., 2007, Astrophysical Journal Supplement, 172, 196
N. Z. Scoville et al., 2007, Astrophysical Journal Supplement, 172, 38

 

"EXO's" - Extreme X-ray / Optical sources

This is a new class of galaxies which I discovered in 2004, that are well detected in deep X-ray studies with the Chandra and XMM telescopes, but completely undetected at optical wavelengths in deep observations with Hubble and large ground-based telescopes (VLT, Gemini, Subaru, Keck etc). They are detected at infrared wavelengths, particularly with Spitzer in the 3 - 8 micron and 24 micron wavelength bands.

The Press release presents the various images and other details about the program, after the public release took place on 1 June 2004.

The original discovery paper is:

A. M. Koekemoer et al., 2004, Astrophysical Journal Letters, 600, L123

 

"MultiDrizzle" - Software for Combining Hubble Imaging Data

I originally wrote and developed the MultiDrizzle software, which uses the "drizzle" software (Fruchter & Hook 2002) to perform automatic registration, cosmic ray rejection and combination of dithered HST images.

The original paper describing MultiDrizzle is:

A. M. Koekemoer, A. S. Fruchter, R. Hook, W. Hack, 2002 HST Calibration Workshop, 337

This also served as the foundation for the subsequent "AstroDrizzle" software, which is now implemented as a successor to it.

 

A few relevant older publications:

Note:
Links to published refereed papers point directly to PDF files made available by the relevant journals: The Astrophysical Journal, The Astronomical Journal, as well as scanned Postscript files accessible via the NASA Astrophysics Data System.


Other Astronomy Sites:

Astroweb:
  • CDS, [NRAO, STScI, MSSSO, ST-ECF, Villafranca, WWW Virtual Library]

  • Other Links - Christianity / Faith and Science:

  • Science and Faith - Discussing Astronomy Research with Religious Audiences (invited talk presented at American Astronomical Society 209th Meeting, 9 Jan 2007, Seattle, WA -- Special Session 174, Talk #174.04)    [printable version]

  • Letter from Pope John Paul II on Faith and Science
  • Christians in Astronomy/Astrophysics (chr-astro)
  • American Scientific Affiliation
  • Christians in Science

  • Other Relevant Webpages:

    Hubble Space Telescope webpage for: Anton Koekemoer
    Linked-in member profile for: Anton Koekemoer
    IAU member webpage for: Anton Koekemoer
    ResearchGate page: Anton Koekemoer
    My google page: Anton Koekemoer

    Anton Koekemoer Anton Koekemoer Anton Koekemoer Anton Koekemoer Jochem Koekemoer
    Disclaimer: Any views expressed on this webpage are strictly personal and are not intended in any way to necessarily represent those of, or be endorsed by, any other entity or organization.