Keck Observing Support Newsletter
Vol. 3
2004 April 19

Contents

Introduction (Bob Goodrich)
KIRMOS—Keck Infrared Multi-Object Spectrograph (Sean Adkins & Bob Goodrich)
Team Keck Completes a Treasury Redshift Survey of the GOODS-N Field (Greg Wirth)
ESI Supports the Stardust Mission to Comet Wild 2 (Bob Goodrich)
Deputy Director Jim Beletic Moves on to Rockwell (Fred Chaffee and Bob Goodrich)
2003B “Top Performers” (Bob Goodrich and Shui Kwok)
Past and Future Events (Bob Goodrich)

Introduction
(Bob Goodrich)

Welcome to the third edition of the Keck Observing Support Newsletter. This edition was delayed in part to bring you some late-breaking news on the highly ambitious near-IR multi-object spectrograph, KIRMOS, that was being designed for Keck. Greg Wirth reports on our highly successful redshift survey of faint galaxies in the GOODS-N field, using Keck’s latest, optical multi-object spectrograph, DEIMOS. For your entertainment, we present the “top performers” for the semester 2003B; a look at the observing programs on each Keck instrument that produced the highest fraction of “open-shutter” time during the last semester. We end with a brief list of recently past and upcoming instrument-related events. I hope you enjoy this edition.

KIRMOS—Keck Infrared Multi-object Spectrograph
(Sean Adkins & Bob Goodrich)

For the past two years an ambitious new wide field near IR multi-object spectrograph (MOS) and imager, called KIRMOS, has been under development for Keck at Caltech. The instrument is intended to provide an 11.4 x 11.4 arcminute field of view (FOV) for imaging and approximately a 4 x 11.4 arcminute FOV for multi-object spectroscopy (R ~ 4000) with a multiplex of 100 to 150 objects. A preliminary design review for KIRMOS was held on March 30 and 31, and unfortunately it is now clear that an instrument with these capabilities will be more expensive than we can afford.

In response to this cost problem the Keck Science Steering Committee and the CARA Board have agreed that the science requirements for a near-IR MOS at Keck should be revisited with a view to defining a capable but less expensive instrument. We also hope that an accelerated development time scale will get the instrument on sky at the same time that, or even faster than, was planned for KIRMOS.

Team Keck Completes a Treasury Redshift Survey of the GOODS-N Field
(Greg Wirth)

In the last decade, the community of Keck observers has made a major contribution to the study of extragalactic astronomy by using LRIS to obtain redshifts and spectra for hundreds of galaxies in the Hubble Deep Field (HDF) and vicinity. As a followup to the HDF project, major orbiting observatories including HST, Chandra, XMM-Newton, and the Spitzer Space Telescope have recently invested large amounts of observing time to obtain extremely deep images in two regions of the sky known as the GOODS (Great Observatories Origins Deep Survey; http://www.stsci.edu/science/goods/) fields. These images will provide an exceptional multi-wavelength picture of galaxies in the distant universe, but redshifts and spectra of these objects are crucial to interpreting these images.

Encouraged by David Koo and Sandra Faber of UCO/Lick, Director Fred Chaffee and the scientific support staff of Keck undertook an extensive redshift survey in the northern GOODS field and committed to releasing the resulting data to the community as rapidly as possible.

This “Team Keck” Redshift Survey was completed in spring 2003 with DEIMOS on Keck II, using 18 slitmasks observed for 1 hour on-sky each to obtain spectra of over 2000 targets. The DEEP2 Survey Team made major contributions to the project not only by donating observing time to the effort, but also by using their superb data reduction pipeline to process the spectra. The data were reduced during the summer of 2003 and all 2000 spectra were analyzed by Team Keck members in fall 2003, producing a catalog of secure redshifts for 1440 galaxies and AGN, plus 96 stars. The sample extends to a limiting magnitude of R=24.4 and has a median redshift of z=0.65; completeness is around 53%.

Through hard work, Team Keck achieved its goals of releasing the data and a corresponding paper describing the survey (http://arxiv.org/abs/astro-ph/0401353) in early January 2004. A press release (http://www2.keck.hawaii.edu/news/tksurvey.html) was also released, describing both our survey and the complementary Keck+DEIMOS survey of this same region completed by Len Cowie’s group at UH (http://www.ifa.hawaii.edu/~cowie/hhdf/acs.html). The website for the Team Keck Redshift Survey of GOODS-N (http://www2.keck.hawaii.edu/science/tksurvey/) not only provides access to the tabular database, but also features a sophisticated browser interface. This interface allows users to inspect the 1-D and 2-D spectra in detail and to download spectra and images of the galaxies. Later this spring, Team Keck plans to make the raw 2-D spectra available via the survey website, completing the data release.

Team Keck is grateful to the National Science Foundation’s Small Grants for Exploratory Research initiative for funding this research.

ESI Supports the Stardust Mission to Comet Wild 2
(Bob Goodrich)

In December, a NASA spacecraft was fast approaching Comet Wild 2, a periodic comet with an orbital period of a little over 6 years. (Upon discovery, the comet’s period was nearly 40 years, but a close approach to Jupiter in 1974 perturbed the orbit significantly.) The NASA probe, STARDUST, was tasked with flying through the comet’s coma and capturing fresh cometary dust particles. These particles are to be returned to Earth in January 2006.

In order to increase the probability of a suceessful mission, NASA asked the Observatory to provide ground-based support in the way of astrometric and photometric information just before the encounter. The astrometry would provide significantly improved orbital parameters and allow ground controllers to target just the right distance from the comet. Too close and STARDUST might not survive. Too far and relatively few particles would be collected. The photometry was designed to provide a measurement of the dust production rate. Again, too much dust production might harm the spacecraft, and require controllers to target the spacecraft at a greater distance from the comet.

So in December 2003, a week or two before the last possible orbital parameter update could be made, a series of ESI observers donated some of their time to get images of the comet, in some cases only 5° above the horizon. Dave Tholen (Univ. of Hawaii) was in Waimea to coordinate the observations and do preliminary analysis. The first observations were taken by Tholen and Bob Goodrich in the last hours of an ESI engineering night. With dawn approaching rapidly, ESI was focused at an elevation of 10°, an unusually low elevation for Keck observations. We then pointed towards a photometric standard star at even lower elevation, to get calibration data for the comet. Just below 6°, the mirror control system (ACS) stopped working. A change of plans; we had to find out how low we could go and still maintain the mirror shape. (We didn’t want to even try doing astrometric solutiosn with 36 separate images of each star, and the comet, in the field!) Some experimentation indicates that 6° was OK, so we went back to the photometric standards. Finally at 5:20 UT we headed for the comet...and the mirror control fell apart again! Each time this happens the telescope must be raised to 15° elevation to recover mirror control. Back to the comet, which was getting ever higher even as the sky was brightening. This time the mirror control held, and we could see the fuzzy comet image amongst the star field. A series of R-band images was taken of different exposure times.

The following observers, Jason Prochaska (UCO/Lick Observatory) and Shri Kulkarni (Caltech) contributed further astrometric data on the following nights, allowing Dave Tholen and the STARDUST team to refine the comet’s orbital parameter with such confidence, that they dared to fly the spacecraft closer to the nucleus than originally planned. And the results? Visit the STARDUST home page and judge for yourself! There you’ll see some spectacular images and even a movie of the STARDUST fly-by. The Cometography Web site has some highlights of the comet’s historical background. And courtesy of NASA/JPL, we provide two of the images of the comet as STARDUST flew within 500 km of the nucleus.

Deputy Director Jim Beletic Moves on to Rockwell
(Fred Chaffee and Bob Goodrich)

How can we possibly thank Jim for all he has contributed during his four years at Keck? As a member of the executive team, Jim’s expansive views, as evidenced by his dynamic concept of “Keck Fleurissant,” were crucial to what ultimately became the Observatory’s Strategic Plan. Jim’s was a constant voice for excellence and innovation within the Observatory; he encouraged us all to “push the envelope” and to “think outside the box” in everything we do. As a manager, Jim reshaped key components of the Observatory’s support functions, including the successful restructuring of the Finance, Outreach and Observing Support departments and the initiation of the Instrument Program Management activity at the Observatory. He also championed the establishment of an archive as a way to maximize the effectiveness of the Observatory’s most important “product,” astronomical data.

In spite of all his management and administrative responsibilities, Jim still managed to remain active in research, hosting an international detector conference in Waimea in 2002 and landing a $1 M grant from NSF’s Adaptive Optics Development Program to produce a new generation of detectors ideally suited to the unique requirements of Adaptive Optics.

Finally, no list of Jim’s contributions would be complete without highlighting his always upbeat “can do” attitude about everything. Jim’s enthusiasm was infectious, as all who interacted one-on-one with him or heard his many “Keck University” talks or his public lecture, “Modern Astronomy: Basic Research to Cutting Edge Technology,” can attest.

We wish Jim, Leslie, and the rest of their wonderful family “a hui hou” and the very best in the new challenges that lie ahead. The Keck Observatory is the richer for Jim’s having spent the last four years among us.

Bon Voyage and mahalo nui loa, Jim Beletic. We’ll miss you.

2003B “Efficiency Hall of Fame”
(Bob Goodrich and Shui Kwok)

Once again we present, for entertainment purposes only, the “top performers” from the last semester, 2003B. These are the observers and the Observing Assistants with the highest fraction of “open science shutter” time in each of our facility instruments. The numbers come from our duty-cycle metrics program.The rows in blue are new records for those particular instruments.

Table 1. “Top Performers” for semester 2003B

Past and Future Events
(Bob Goodrich)

Below is a brief outline of past and future events within the development sector of CARA. Many of you may not have heard of the “AO CCD” project. Many of you may not have heard of the “AO CCD” project. This is a project being led by James Beletic and Sean Adkins here at Keck that will develop new CCDs especially designed for improved performance in AO wavefront sensing. This project is one of 6 that were funded by the NSF in the first round of a program operated by NOAO and called “The Adaptive Optics Development Program” (http://www.noao.edu/system/aodp/). This project will take place over the next three years in collaboration with MIT/Lincoln Labs, SciMeasure Analytical Systems, the Center for Adaptive Optics and UCO/Lick.

The K1 Shutter Drive Upgrade project (see the Keck Observing Support Newsletter, Vol. 2) passed its CDR with flying colors. To quote one observer, “This is the first (design review) I’ve seen where I believed what they were saying.”

The Interferometer’s V² Operational Readiness Review also went very well. In the words of Director Fred Chaffee, “This is a major milestone in the history of Keck Observatory. Interferometry has come of age.”

Note that any dates in the future in this table are always subject to change.

Table 2. Recent and future events of note