Message from the Director

Aloha, and welcome to our Fall 2018 Observers’ Newsletter.

In this edition, we are pleased to announce several exciting instrument upgrades, from NIRSPEC to NIRC2, along with multiple AO projects. This includes the Keck All-sky Precision Adaptive optics (KAPA), which recently was awarded a $7 million grant from the National Science Foundation. With the various AO upgrades underway, we are poised to deliver the next-generation of AO capabilities that will strengthen W. M. Keck Observatory’s leadership in high angular resolution science.

We are now standing at the edge of a new frontier in Time Domain Astronomy, after the successful commissioning of the Keck I Deployable Tertiary Mirror system (K1DM3). We are eagerly anticipating making this capability available for routine use starting semester 2019A. Congratulations to the entire K1DM3 team, made up of staff from UC Santa Cruz and the Observatory! K1DM3 was the final project that Jerry Nelson worked on for Keck, and it is a fitting tribute to his remarkable abilities.

After months of volcanic eruptions and earthquakes, Kilauea has finally settled down. We are grateful that our staff remained safe and our facilities suffered no significant damage. The volcano is unpredictable, but for now we are enjoying a period of calm (and clean air) not seen in decades.

Our Keck Visiting Scholars Program is now in its second year. The KVSP 2018 Cohort consists of eight talented graduate students who are gaining hands-on experience at our Observatory, in the areas of software, instrumentation, and data reduction pipeline improvements. It is also a valuable professional networking opportunity for the future leaders in the field. When you next visit our headquarters, please take the chance to meet with these talented individuals.

Lastly, thank you to everyone who helped make the annual Keck Science Meeting, held September 20-21 at Caltech, such a success. We had a record turnout; more than 160 attendees participated in engaging presentations. Many also participated in breakout sessions with our Support Astronomers, designed to gather input from you, our science community, on ways we can continue to support and advance your research needs.

We also celebrated our 25^th Science Anniversary at the Keck Science Meeting with the premiere of The Impossible Telescope, a short film that tells the story of how Keck Observatory came to be.

I am grateful for all the positive feedback I received at the meeting about the staff at the Observatory. I am greatly encouraged to see our collective work resulting in such high energy and enthusiasm by the community, a quarter century after the start of science operations. We look forward to continuing to serve our science community as effectively over the next 25 years, and beyond.

A hui hou kakou,
Hilton Lewis, Director
W. M. Keck Observatory

Things to Know for Semester 19A Observing

Randy Campbell,
Observing Support Manager.

NIRSPEC is undergoing a significant upgrade. The major components of the upgrade are: replacing the spectrometer detector with a Teledyne H2RG array, upgrading the slit viewing camera, SCAM, with a new 1-5 μm H2RG, replacing the obsolete transputer-based electronics, changes to the SCAM opto-mechanical layout, a new host computer, changes to the electronics systems, and development of the associated software needed for each subsystem.

Other aspects of the upgrade will improve repeatability and stability of the positioning of echelon and cross disperser gratings, as well as increase the thermal stability of the instrument. NIRSPEC will be offline for an extended period this semester (18B) and back in service for two months starting in December 2018. The SPEC and SCAM detector upgrades to HR2Gs should be installed by December with the SPEC detector released for routine science operations. However, NIRSPEC will be unavailable for a month’s time between February and March 2019 to make fine adjustments to SCAM and the cross disperser. NIRSPEC will again become available after a few engineering nights in March.

The NIRSPEC team at the cleanroom on the summit, from left to right: Chris Johnson, Jiman Sohn, Emily Martin, Ken Magnone, Greg Doppmann and Mike Fitzgerald.

A NIRC2 upgrade project is also planned for the Keck II’s AO workhorse instrument in the spring of 2019. The upgrade will require a single service mission to add a few new components. These include a vortex coronograph optimized for M-band (4.5 μm) and a low dispersion element for low-resolution spectroscopy.

The NIRC2 upgrade project will be planned around the observing schedule such that this work will not impact any science programs allocated in 19A. This can be accomplished by taking advantage of natural windows in the schedule that occur during dark runs where KCWI and DEIMOS are scheduled.

The Keck I Deployable Tertiary, K1DM3, is currently undergoing commissioning and should be in operation for the 2019A observing semester, ushering in a new era of time domain astronomy at WMKO.

The K1DM3 will enable rapid instrument changes that will offer Target of Opportunity, ToO, users the option of two Nasmyth foci instruments, OSIRIS and HIRES, and one of two Cassegrain focus instruments, LRIS or MOSFIRE, on any given night.

Assuming the commissioning is complete in the fall of 2018, we anticipate Keck I instruments and operations to be ready for ToO instrument changes in the 2019A observing semester (Feb, 2019). ToO observations will then be using a trigger mechanism and database infrastructure to exchange information accurately and efficiently between the ToO PI and the observatory.

The figure below is a screen shot of the beta version under development for the ToO Trigger interface that will be available via the “WMKO Observer Login” page.

Fig 1. Beta version of a ToO Trigger tool that will be available on the WMKO Observer Login page. This tool, developed by Josh Riley at WMKO, will help facilitate efficient and accurate communication of ToO observations.

The WMKO priority is to make Keck I TDA ready for the 2019B observing semester to maximize the utility of the deployable tertiary K1 DM3. Users will have necessary information for the ToO available via the Observer Login page regarding instrument accessibility, instrument configuration, interrupt status, and current telescope schedule.

The information needed to coordinate the interrupt will be provided by the ToO PI and uploaded to the observatory using the menus on this page. In addition, there are plans to extend the TDA readiness infrastructure to Keck II.

WMKO will continue to improve the TDA readiness and work with both TDA and classical PIs to refine the process, improve the tools, and maximize both TDA and classically scheduled science.

Volcanic Eruption Impact to Observing

Carolyn Jordan,
Lead Observing Assistant.

The new eruption pattern for the Kīlauea volcano that began in early May has had a significant impact on the Big Island, and all of the observatories on the summit have experienced effects of the eruption on their operations.

On May 3, the island experienced a large 6.9 magnitude earthquake associated with the eruption, which caused a small amount of damage to the Keck I telescope, rendering it inoperable for several nights while repairs were conducted.

During this event, the Keck I telescope had been up on the hydrostatic bearing system (HBS) that allows it to move freely at night. As a result of the increase in seismic activity associated with this eruption, the observatory has issued new guidelines for the Observing Assistants to follow when an earthquake occurs during night time observing.

The current guidelines state that if the summit staff feels a significant earthquake, or has an indication via their instrumentation that a significant earthquake has occurred, they are to stop operations and take the telescope off of the HBS system. They are to inspect facility, look up the reported earthquake magnitude, and consult with our engineers on how to proceed.

These procedures are in place to ensure that new damage has not occurred and that we are prepared for the possibility of additional, potentially damaging aftershocks.

Another concern for observatories is the increased amount of SO2 gas that is being released from the volcano. There have been several occasions where a significant smell of SO2 has been reported at the summit, and there is concern about the effect this gas might have on our sensitive optics and electronics.

The biggest potential for damage is when SO2 combines with water, creating sulfurous acid which can be highly corrosive to the mirror surface. As a result of the increased risk to operation, the following guidelines have been implemented:

If the dew point differential between the primary mirror, secondary mirror, or outside temperature reaches 5 degrees or less for more than 5 minutes, the Observing Assistant is to close the shutters.

If the Observing Assistant can smell SO2 in the air, they are to close the shutters at an outside relative humidity of 70% or higher.

The Observing Assistants are also monitoring for any ash plumes resulting from volcanic explosions. This ash is highly corrosive, and the OA's have the responsibility to close the shutters if any ash is detected.

As the eruption changes and we work to understand and quantify the risks more, changes may be made to these guidelines. Your Observing Assistant and Support Astronomer should be able to inform you of the restrictions during your night of observing.

If you have any questions, please speak with Randy Campbell.

NOTE: At the time of publishing, we have reverted to standard operations and the informations contained in this article no longer apply. Because of the dynamic nature of the ongoing eruption, these restrictive criteria could be reinstated at any time, so we prefer to present them to our observers as they were during the active phase.

A plume from one of the volcanic eruptions as seen from Maunakea, taken on Wednesday, May 9, by W. M. Keck Observatory Engineer Sam Park.

Keck Visiting Scholars Program

Alessandro Rettura
Support Astronomer.

Through the generous gift of a donor, in April 2017 we launched a pilot visiting program for early career scientists at Keck Observatory, designed to inspire and develop the next generation of scientists and instrumentalists.

Ned Molter (UCB), Katherine de Kleer (Caltech), Gagandeep Anand (UH), Anna Ciurlo (UCLA), and Leo Alcorn (TA&M) were invited to visit Keck Observatory for periods ranging from three to eight weeks.

The tangible benefits of having them performing research or working on projects under the supervision of Support Astronomers have been clearly demonstrated: new data reduction pipeline (DRP) modules have been written, original science results have been published, and new operational features in Adaptive Optics (AO) and the Twilight Program have been developed.

This year, the program continues and has been further expanded. An open call for applications has been issued and has created interest from the early career Keck Observatory and NASA communities with 23 applications received by the March 31st deadline.

The proposals received spanned many areas of matching interest with the Support Astronomers: software and DRP improvement projects, science programs exploiting our instruments archival data, instrumentation projects, and projects aimed at improving our operational efficiency.

As a result of this competitive process, a total of eight graduate students or postdocs (in their first three years of appointment) have been invited to visit Keck Observatory in 2018 and work under the mentorship of a Support Astronomer.

Here is the Keck Visiting Scholars (KVS) Class of 2018 and their approved projects:

Emily Martin (UCLA grad student - Mentor: Greg Doppmann) – “NIRSPEC Slit-viewing Camera (SCAM) optical design, implementation and characterization” – (1 2weeks)

Gaël Noirot (JPL Postdoc - Mentor: Alessandro Rettura) – “Study of z~2 clusters with Spitzer and MOSFIRE” – (4 weeks)

Ariel Graykowski (UCLA grad student - Mentor: Percy Gomez) – “NIRES data reduction automation of non-sidereal targets” – (4.5 weeks)

Farzaneh Zohrabi (Mississippi State University grad student – Mentor: Sam Ragland) – “Probing the immediate surroundings of Habitable exoplanet hosts with NIRC2” – (8 weeks)

Geoff Chen (UC Davis grad student – Mentors: Jim Lyke ,Sherry Yeh) – “Implementing the drizzling technique in the OSIRIS data reduction pipeline” – (7 weeks)

Chris Curtin (Swinburne grad student – Mentor: Luca Rizzi) – “Continuous improvements to the KCWI python pipeline” – (7 weeks)

Thomas Lai (U of Toledo grad student – Mentor : Carlos Alvarez) – “Monitoring the DEIMOS Throughput” – (6 weeks)

Ian McConachie (UC Riverside – Mentor : Percy Gomez) – “Study of z > 3 brightest cluster galaxies (BCGs) with NIRES and of their environment with MOSFIRE" – (4 weeks)

The Keck Visiting Scholars are normally expected to:

give an introduction talk in their first week of visit to introduce themselves and their previous scientific interests to the Observatory

perform the aforementioned software, instrumentation, or science projects under the supervision of a Support Astronomer

give an exit talk during the last week of their visit to highlights their results.

Keck Visiting Scholars also actively participate in Keck Observatory social and scientific activities, i.e., attend seminars and outreach events.

KVSP 2018 is currently well under way. At the time of writing, three scholars have already completed their visit, one is currently working on the instrumentation project related to the NIRSPEC upgrade (see Fig. 1), and three more will visit during Fall of 2018.

Fig 1. Highlights of the 2018 Keck Visiting Scholar Program: (Top left) Visiting Scholars during a tour of the Keck Telescopes guided by SA Alessandro Rettura, who is coordinating the program. (Top right) Gaël Noirot giving his exit talk on the last day of his internship. (Bottom left) Emily Martin in the clean room at the summit working on her project related to the NIRSPEC upgrade. (Bottom right) Geoff Chen, Farzaheh Zohrabi, and Ariel Graykowski at the summit of Maunakea, standing in front of the Keck II telescope.

Aloha Gary Puniwai

Carolyn Jordan,
Lead Observing Assistant.

If you have had an observing run in the past few months, you may have noticed that one of the old, familiar faces on the Observing Assistant crew has been missing.

In early May, Gary Puniwai retired from his job as an Observing Assistant after 22 years on the job.

Gary was one of our most senior OAs, and was well-known for his efficient operations and cool-under-pressure attitude. He had gathered a wealth of knowledge about the telescope over his years, and was very committed to the Observing Assistant team and to helping our community of observers achieve their best science.

Gary enjoyed working on Maunakea and always had a camera with him to capture the beauty of the mountain. We already miss Gary’s smile and relaxed attitude on the night crew!

We wish Gary all the best in his retirement and hope he enjoys getting to spend more time with his grandchildren.

Aloha Gary and a hui ho!

(Left to right) Joel Aycock, John Pelletier, Alan Hatakeyama, Julie Renaud-Kim, Gary Puniwai, Cynthia Wilburn, Carolyn Jordan, and Barbara Schaefer.

AO Operations and Development

Jim Lyke,
AO Operations Lead Scientist.

I’m very pleased to introduce our new AO Operations Scientist, Juan Carlos Guerra
(jguerra@keck.hawaii.edu).

Juan Carlos joins Keck with plenty of experience at ESO-VLT and LBT. Once familiar with Keck AO, he will strive to maximize the science output for AO.

This will be a broad scope including better performance monitoring, easing calibrations, and troubleshooting image quality issues.

Both the Keck I and Keck II AO systems continue their amazing scientific productivity. Our AO systems are aging and we strive for them to age gracefully and to make improvements along the way.

We’ve overcome some challenges in the past year and have an exciting year of upgrades ahead of us. We have replaced the Keck I STRAP and Keck I LBWFS systems this year due to failures with minimal downtime. Both lasers have remained on-sky. For the next year, we have:

Keck I

TRICK (Near Infrared Tip-Tilt Sensor) operations ready for testing
Performance Optimization

Keck II

Pyramid Wave Front Sensor (operating in Near Infrared)
Fiber Injection Unit for NIRSPEC
Fiber Injection Unit Coronagraph
TOPTICA laser spares
PSF-Reconstruction

The newest project that will be added to the list is KAPA: Keck All-sky Precision Adaptive optics. The NSF MSIP recently selected the KAPA proposal, which will improve the Strehl ratios and sky coverage for the Keck I AO system. As a result of an NSF MRI funded activity along with the KAPA project, we will also implement a new Real Time Controller in 2020.