I'm a Senior Research and Instrument Analyst in the ACS (Advanced Camera for Surveys) Group in the Instruments Division
at the Space Telescope Science Institute
(STScI)
located in Baltimore, MD. The STScI is operated by
AURA for
NASA and is a research center
whose primary mission currently involves supporting science
with the Hubble Space
Telescope. STScI is also the science and operations center for the
successor to HST, the
James Webb Space Telescope (JWST),
which may be launched by 2018.
The Institute is located on the Homewood Campus (Arts and
Sciences and Engineering) of the Johns Hopkins
University.
For my first four years at STScI (July 1985-March 1989), I worked for CSC in the Guide Stars group, working with Barry Lasker, Conrad Sturch, Brian McLean, Jane Russell, and others, helping to create the Version 1 HST Guide Star Catalog (Lasker et al.) and all-sky digital image archive which was later compressed to form the CD-ROM sets known collectively as the Digitized Sky Survey (DSS). I did not work on the compression and the production of the DSS itself, but on the creation of the original digital images from which it was derived. In March 1989, I switched from CSC to AURA and worked in the front-end User Support area of the STScI, being primarily involved with Phase I (proposal development and peer review) for the first 5 or 6 annual HST observing Cycles, and I worked on Phase II tasks (helping develop, write, implement, and manage selected observing programs) from the original Guaranteed Time Observer (GTO) programs of Cycle 0 and the original General Observer (GO) programs of Cycles 1 through 13 or so here at STScI, until I switched to the Instruments Division and began working on instrument calibration in October 2004. During that time, I worked for and with Bruce Gillespie and Abhijit (Abi) Saha in the User Support Branch and with Neta Bahcall and Nolan Walborn and Kirk Borne in the Phase I peer review support process and early Phase II support. Later, as the Institute reorganized, I worked for and with Peg Stanley, Dan Golombek, and Denise Taylor in the Phase II design, verification, implementation, and general management of observing programs. After switching to the Instruments Division, I have worked for and with Roeland van der Marel, Ken Sembach, Marco Sirianni, and Linda Smith in the ACS group, and for and with Paul Lee, Francesca Boffi, and Max Mutchler in the DAB/RIAB, and of course I have worked with many others within these groups on various projects. During all these years and up through the present, in addition to the functional work, I have also done research and have been a researcher on a number of programs at various observatories like USNO-Flagstaff, KPNO, the VLA, CTIO, La Palma (NOT), and including being a coI on quite a few HST programs, as detailed below. Plus, I have been the PI of external VLA and NVO science programs, on which I am still working when I can make the time, and the science PI of my own portion of a number of HST observing programs. And, I am a co-investigator on one of the large, new HST Multicycle Treasury programs, CANDELS, following up work on some of the earlier HST programs of which I have been a part, as well as others new to me. Several years ago, and looking forward to the future, I also worked on testing prototype Design Reference Mission (DRM) observing programs for JWST with Massimo Stiavelli and others, including tests of the implementation of JWST "deep field" extragalactic programs designed to try and observe the earliest galaxies and the first stars in the universe.
*** 1985-1994 ***
In the Guide Stars project at STScI, I worked under the direction of Barry Lasker and Conrad Sturch from July 1985 through March 1989. At the time, it was the largest astronomical catalog ever produced (about 18 million objecs in Version 1.0), and it was the first optical all-sky digital image archive, and the beginning of the STScI Data Archive as well. It was the vision of Barry Lasker to create this wonderful, great resource against the constant odds of funding and operational pressures, etc., and it has proven to be a boon to Hubble Space Telescope operations, making them much more efficient, as well as a valuable scientific tool. In addition to this, if anyone anywhere wants to use the internet to see the heavens, for optical wavelengths, it is often the basis of what they will see whenever they call up a piece of sky by its coordinates. Today it seems a simple matter, and something we take for granted, to be able to call up a finder chart via our computers at work or at home or at some remote observatory on a mountaintop, or in the space shuttle, but before these photographic images were digitized and the compressed versions made available on the World Wide Web, there was no such facility. Some GSC and DSS information is here:
The HST Guide Star Catalog
And some information about the Digitized Sky Survey, which was derived from the compressed versions of the digital images which I helped create, is here:
The Digitized Sky Survey
At about that same time, I became very interested in galaxy interactions and galaxy evolution, both in clusters and in the field. One of the first projects I became involved in was working with Brad Whitmore and collaborators on Polar Ring Galaxies. I began observing some of these at Cerro Tololo Inter-American Observatory in Chile in 1989. I also got some experience using the VLA (Very Large Array of radio telescopes of the National Radio Astronomy Observatory, in New Mexico), being PI of a VLA snapshot program of many sources from the Texas Radio Survey Catalog in 1990. I was also involved with a monitoring program on ULIRGs, getting data from the USNO-Flagstaff on galaxies like Arp220, etc. with Kirk Borne, Nino Panagia, and Hal Levison.
Polar Ring Galaxies - I wasn't involved in taking this Hubble Heritage image, but
it is quite nice as an example of the class of object! For my work on Polar Ring
Galaxies, see the reference Whitmore et al. in AJ 100, 1489 ( Nov. 1990 ).
You can also see more about polar ring galaxies at
Doug McElroy's
polar ring galaxies page. The Hubble Heritage Project took
images of the Polar Ring Galaxy NGC 4650-A as decided by the votes of the
general public who picked it overwhelmingly from a group of several possible
targets. A larger version of the image is
here at the
Hubble Heritage Polar Ring Galaxy NGC 4650A pages and there is some text about it
here.
*** 1994-2000 ***
After that, by late 1993 or early 1994, my work also expanded to working on the intermediate redshift (z~0.4) galaxy cluster CL0939+4713 (Abell 851) with Alan Dressler and collaborators as part of the demonstration of the capabilities of the new WFPC2 camera after the first HST Servicing mission. Then it was on to work on massive star clusters and globular clusters with Brad Whitmore again, and later the starburst phenomenon in collisional ring galaxies (e.g. the Cartwheel, IIZw28, etc.) and Ultraluminous Infrared Galaxies (ULIRGs) with Kirk Borne and collaborators. Eventually it evolved into working with Bob Williams, Harry Ferguson and Mark Dickinson and collaborators in the HDF-related areas below, as well as the work on Gamma Ray Bursters, including the latest DD (Director's Discretionary Time) program, on the amazing GRB 990123 (see more, below), with Steve Beckwith and Paul Goudfrooij.
Medium Redshift ( z ~0.4 ) Galaxy Cluster CL0939+4713 ( Abell 851 ) - This
was the first deep image ( 10 orbits ) taken with the new WFPC2 camera in
January 1994 after the first HST servicing mission and was, at the time, one
of the deepest optical images ever taken of the night sky. It validated the work done
by Dressler, Oemler, Butcher, and Gunn with the WFPC-I in the initial period
of HST operations before the new WFPC2 camera and its corrective optics were
installed, and it demonstrated that HST could do this kind of science very
well and very efficiently with the new optics. This had been unexpected before,
but Nature gave us a gift in that the surface brightnesses of distant, early
galaxies were typically higher than expected, making their morphologies and
sizes, and number counts, etc. great problems for HST to study. Along with the
later images of 3C324 by Mark Dickinson et al. which were even deeper images of
objects at even higher redshift ( z ~1.2 ), and data from the Medium Deep Survey,
these early WFPC2 observations of CL0939+4713 helped inspire the idea of the Hubble Deep
Field. The reference for these observations is Dressler, Oemler, Sparks, and
Lucas in ApJ Letters 435, L23 ( 1 Nov. 1994 ).
The Cartwheel Galaxy - Supersonic gas clouds plunging into the nucleus of
the Cartwheel, from Struck, Appleton, Borne, and Lucas (AJ 112, p. 1868), 1996.
Various parts of the work on this galaxy are published in collaboration with
C. Struck et al., P. Appleton et al., and K. Borne et al. Two links to more PR
images and info are
here, in approximated true colors (from two bandpasses) and here
in false color and with radio contours.
M87 Globular Clusters - A project in which we (Whitmore et al.) studied
the nature of the Globular Cluster Luminosity Function (GCLF) of the giant
Virgo elliptical galaxy M87 and used it to derive an estimate for the Hubble
Constant and the age of the universe.
Ultraluminous Infrared Galaxies - HST WFPC2 and NICMOS snapshot surveys of
these galaxies which are extremely bright in the infrared and are mostly
interacting and/or merging galaxies. This work is underway as a collaboration
with K. Borne et al. Here is a link to some information for the public about
our
multiple galaxy merger ULIRG observations, and a link to a
higher resolution PR image.
The earlier work on CL0939+4713 lead to involvement in the original Hubble Deep Field - North Project, and eventually to its successor, the Hubble Deep Field - South, and various GO follow-up programs to the original Director's Discretionary programs done as a service to the astronomical community.
The Hubble Deep Field
- North - The deepest optical image of the universe when it was taken in
December 1995. (The HDF-South STIS monochromatic image, some other fields in
the Andromeda Galaxy M31, images of some Milky Way globular clusters, and
eventually the Hubble Ultra Deep Field later exceeded its depth. The Hubble
Ultra Deep Field, in which I also participated (more on this below), is now the
deepest detailed optical image ever taken.) The primary technical reference is
Williams et al. 1996, AJ 112, 1335. I am also involved in follow-up GO programs
to observe the HDF-N with STIS (Ferguson et al.) and with NICMOS (Dickinson et
al.)
HDF-N NICMOS GO 7817 Page - A Complete NICMOS IR Map of the HDF-N by our
collaboration, Dickinson et al.
The Hubble Deep Field - South - A southern counterpart to the original
HDF-N but with some other new features as well, such as STIS spectroscopy and
imaging of a z=2.2 QSO and its adjacent field, plus parallel imaging in the
NICMOS NIC3 camera, and parallel WFPC2 imaging in the same 4 bandpasses as were
done for the original HDF-North.
An Extremely Red Galaxy in the HDF-S NICMOS Field (Abstract) - Our paper
on an extremely red galaxy found in the HDF-S NICMOS test images by T. Treu et
al. on which I am a co-author.
Gamma Ray Burster GRB 970508 (Abstract) - One of the first science
images taken with STIS after the second HST Servicing Mission. The image
and some more text is available via
the OPO pages
on this object.
Gamma Ray Burster GRB 990123 - I've also been involved as
a co-I in work on putting together Steve Beckwith's program of Director's
Discretionary HST service observations
(GO/DD 8394) of the GRB 990123,
an incredibly bright GRB. Here is a version of the
processed image of
GRB990123 from the HST GRB collaboration.
*** 2000-Present ***
Since around 2000, much more of my time for science has been taken up by my involvement with large, deep extragalactic survey programs with HST. As well as finishing up the data paper on the HST HDF-S Flanking Fields (3 different instruments, and something like 30 or so different fields around the HDF-S) which involved a very large supporting cast, and especially extra effort from my colleagues Richard Hook, Ed Smith, and Harry Ferguson, I have been involved with several such surveys with the Advanced Camera for Surveys (ACS) and NICMOS.
Hoag's Object - A peculiar
galaxy which I observed for the
Hubble Heritage Project. There were
very few orbits available to do this project at the time. Back when she was a
summer student in 2002, my Institute colleague Tiffany Borders did the hard
image processing work which resulted in the nice color PR image seen here.
GOODS co-Investigator - This
is the original GOODS project. I was a co-I on the Giavalisco et al. HST/ACS
GOODS program, and involved a bit in the Dickinson et al. Spitzer GOODS program
and some publications from it, e.g. Papovich et al. As part of GOODS, and later
as a part of my new Instruments Division science support duties (since I was
already familiar with the process), I also helped search for distant supernovae
for the Riess et al. program on Dark Energy and the cosmic acceleration. I am
also a co-Investigator on the Conselice et al.
NICMOS GOODS infrared imaging of
massive red galaxies in the GOODS northern and southern fields.
Hubble Ultra-Deep Field Team Member
- This is the original HUDF. I am also a co-Investigator on the Stiavelli et al.
UDF follow-up (aka the UDF05 project) in which we are
taking ACS optical images of the original UDF NICMOS parallels in which we took
the deepest near-infrared images ever taken of the night sky.
My NVO Program on Radio
Galaxies - Starting in 2005, I was PI of this funded externally-peer reviewed VO program which incorporates VLA observations which I made of a sample of extragalactic radio sources from the Texas Interferometer Survey.
I have also been involved in thermal vacuum testing of the new WFC3 camera in 2007 and 2008, and in similar testing of the new ACS-R components both of which were installed on HST by the STS-125 astronauts during our HST Servicing Mission 4 (SM4) in May 2009. I was a member of the SM4 ACS-R ERO Team, and I suggested this target, Abell 370, for our ERO observations, so I was very happy to see it happen!
CANDELS: Cosmic Assembly Near-IR Deep
Extragalactic Legacy Survey, one of three large HST
Multi-Cycle Treasury programs. I am a co-investigator on the CANDELS program,
which follows in the wake of earlier major HST and other extragalactic research
programs on the HDF-North, HDF-South (though not observed in CANDELS), GOODS
(North and South), GEMS, COSMOS, EGS, UDS, UKIDDS, and etc. Observations begin
in the latter half of 2010.
HST Frontier Fields,
a Director's Discretionary Community Service program to search for extremely
high-redshift galaxies, i.e. using the gravitational mass and gravitational lensing
effect of foreground but distant, massive galaxy clusters to magnify very young galaxies
in the early universe behind/beyond them, and thus aid in the search for these very
young galaxies in the very early universe, in an attempt to push Hubble's capabilities
as far as we can towards and in anticipation of those of JWST before it is launched
late in this decade of the 20-teens. The observations will consist of ~70 orbits each
in ACS and WFC3 in several optical and infrared filters, on each of 6 central galaxy
clusters and on 6 "emptier" parallel or non-cluster fields to the side of each cluster.
*** Some Other Things ***
Here is our paper on NGST (now JWST) and tidal tails:
The Archival Study of Extragalactic Tidal Tails in NGST Observations
This paper was originally presented for the STScI Galaxies Journal Club NGST study, and is based on work from our (Bushouse, Colina, Lucas, and Borne) contribution to the GSFC "Science With NGST" meeting which is referenced in the paper.
More thoughts about NGST (JWST) survey or snapshot mode imaging and the archival
value of this can be found in this paper (Goldader, D. Smith, and Lucas).
NGST: An Opportunity For Systematic Archival Research
This paper has also now been incorporated as one of the supporting documents for the HST Second Decade review project as well.
My Most Memorable AAS Meeting
This paper is about my adventures on the way to the AAS Meeting in San Antonio in January 1996 for the presentation of the original Hubble Deep Field, and is an updated version of a paper which was presented at the June 1999 100th Anniversay AAS Meeting in Chicago, since the AAS requested such contributions from its members for that meeting. Written in a great hurry just before the meeting, it would have been both shorter and better if I'd had more time to edit it! And since then, for consistency and simplicity, I have kept it mostly the same, just adding and updating a bit. But it is still probably one of the first and still one of the few AAS papers ever to be presented in which the author could readily link such seemingly disparate things as the Hubble Deep Field, Stephen Hawking's chauffeur, and Chubby Wise's fiddle, and probably one of the very few for which the author played a tune on the fiddle for a group of interested attendees at the end of the day!
SPIE-Munich 2000
A paper on common, unified observatory and educational tools for the future.
Magnifying the Past: Galaxy Clusters and Gravitational Lensing
My STScI Public Open Night talk of 23 February, 2010: the broadcast and pdf versions of my PowerPoint slides.
Frontier Fields Google Hangout Video of 12 June, 2014
I was interviewed for this along with some other memebers of the Frontier Fields Team.