MRI: Development of an Improved Keck II Laser Launch Facility
Enhancing the Scientific Return of Keck Laser Guide Star Adaptive Optics
A proposal to the National Science Foundation
Major Research Instrumentation Program
Program Solicitation: NSF 09-502
Closing Date: January 22, 2009
Peter Wizinowich, W. M. Keck Observatory
Andrea Ghez, University of California Los Angeles
Michael Liu, University of Hawaii
Claire Max, University of California Santa Cruz
Authorized Organizational Representative:
W. M. Keck Observatory
The AOR of each organization involved in this proposal is aware of this submission.
This instrument development proposal is intended to provide a new laser launch capability for the W. M. Keck Observatory’s (WMKO) laser guide star (LGS) adaptive optics (AO) facility on the Keck II telescope. Our proposed approach is to replace the existing side launch laser facility with a new center launch facility which will produce notably improved scientific performance.
Background: The twin 10 m Keck telescopes were the first of a new generation of ground-based, large optical/infrared telescopes, offering major improvement in light gathering power and angular resolution. WMKO was also the first to implement both natural guide star (NGS) and LGS AO systems in order to achieve angular resolutions in the near-infrared that match the capabilities of the Hubble Space Telescope in the visible. Over two hundred refereed science papers have been produced using the Keck AO systems, including fifty-five with the more recently installed LGS AO system. Astronomy with LGS AO is still very new, with less than 10 peer-reviewed papers from other observatories. The WMKO 2002 Strategic Plan identified “Maintaining world leadership in high angular resolution astronomy” as a 20-year strategic goal paramount to the Observatory’s mission. The WMKO 2008 Strategic Plan reiterates the importance of AO to the Observatory’s future with a strong priority given to the Observatory’s Next Generation AO (NGAO) facility: “NGAO will reinvent Keck”. In this proposal we describe a new laser launch facility for the Keck II LGS AO system that will significantly increase the existing system’s scientific return in the near-term and which will directly support NGAO in the longer term.
Intellectual Merit: In addition to providing the first NGS and LGS AO facilities on a large telescope, WMKO has endeavored to continually improve the scientific performance and capabilities of these systems. The resultant scientific attractiveness of these facilities has been commented on by many observers, including the following recent quote from Dr. Bruce Macintosh: “As I get more access to data from other observatories, it’s clear that Keck unambiguously has the best AO system of any telescope in the world.” Every significant new AO improvement has triggered new discoveries by our observers from the structure of the rings of Uranus, to the search for extrasolar planets, to the size and nature of the environment around the black hole at the center of our galaxy, to the morphology of high-redshift galaxies. All Keck II LGS AO science would benefit from the proposed upgrade which is predicted to provide sensitivity improvements of up to 65% and factors of up to two in both photometric and astrometric accuracy (e.g., 2x in astrometry leads to 8x in dynamical mass determination accuracy).
Technical Improvements: The Keck II LGS AO facility currently projects the laser from the side of the telescope. This results in significant perspective elongation as seen by the AO wavefront sensor due to the finite thickness of the sodium layer. We will significantly improve the resultant wavefront sensor measurement error by projecting the laser from behind the telescope’s secondary mirror. This requires the procurement and installation of a compact reflective launch telescope and the implementation of a beam transport system between the existing laser and the launch telescope. In addition to providing improved scientific productivity in the near-term, we will also design and implement the overall system so that it is easily upgradeable to our future NGAO multiple LGS system.
Broader Impacts: The significantly improved science capabilities of the Keck II AO facility produced through this proposal will be directly available to a broad community of astronomers including those in the Caltech, University of California and University of Hawaii communities through their time allocation committees. The entire U.S. community will have access through NASA membership in the WMKO partnership and the NSF-funded National Optical Astronomy Observatory’s Telescope System Instrumentation Program. WMKO will reinforce its role in the training of world experts in the field of LGS AO. WMKO will also continue to offer educational programs and services to work with local residents, educators and especially students, including its strong participation in the Akamai Workforce Initiative aimed at local Hawaii university and community college students.
Table of Contents
Project Summary i
Table of Contents iii
Project Description 1
References Cited 19
Biographical Sketches 23
Other Personnel 36
Budget and Budget Justification 37
Current and Pending Support 40
Supplementary Documents 45
Letters from unfunded participants 48
List of Suggested Reviewers 52