Conversation with Alistair Walker (NOAO Astronomer)
What led to your interest in astronomy, Alistair?
A specific event — a close opposition of Mars — sparked my interest in astronomy at the age of 8. Not too long thereafter I read Fred Hoyle’s “Frontiers of Astronomy.” I recall being captivated by the idea that stars tunneled through interstellar gas, accreting as they went, unfortunately incorrect! Building telescopes followed, including a “richest field” telescope that delivered spectacular views of the southern Milky Way. Despite a diversion into a strong interest in chemistry in high school, I majored in Physics at Otago University and did an astronomy project for my Masters thesis. In those days, there was no professional astronomy in New Zealand. So, having decided to follow my interest in astronomy, I moved to Cape Town to do a PhD with Brian Warner, the recently appointed head (among three faculty!) of the University of Cape Town Astronomy Department. Working with Ed Nather and Wayne van Citters (U. Texas), Brian had just installed one of the first mini-computer controlled instruments — a high speed photometer — for use on the just-opened South African Astronomical Observatory facilities at Sutherland.
What do you do currently at NOAO?
I’m presently on a 6-month sabbatical leave, much of which I’m spending in my office, catching up on some research projects and initiating others. I’m interested in resolved stellar populations, and most of my research these days seems to involve globular clusters in one way or another, or local group galaxies, with observations from both ground- and space-based facilities.
I’m now the Instrument Scientist for the Dark Energy Camera, a 500 megapixel prime focus instrument for the Blanco 4-m telescope. The Dark Energy Camera is being built by a consortium led by Fermilab and is expected to be installed in 2011. Over the next two years, I will spend a lot of my time participating in various aspects of building and testing the instrument and installing and commissioning it. I am also involved in scientific and operations planning for the Large Synoptic Survey Telescope.
How long have you worked at NOAO and how have you contributed to its mission?
I’ve worked at NOAO in Chile for 24 years. During that time, I have just about done everything. I just finished a five-year term as Director of the Cerro Tololo Inter-American Observatory (CTIO). For many years I was the CCD Czar and spent lots of time inside dewars and coaxing detectors to behave themselves. I was also responsible for CCD imaging on all the CTIO telescopes, so lots of time was spent on the mountain. More recently, I led a talented team of engineers in building the Optical Imager for the Southern Observatory for Astrophysical Research. In parallel, I moved into engineering and, finally, observatory management positions.
What do you like about working at NOAO?
I like the combination of being able to work on cutting-edge instrumentation projects, and being able to do science projects at a first-rank observatory. Keeping things working reliably so that visiting astronomers can take away high-quality data, and making improvements to telescopes, instruments and operations is always an interesting challenge! I’m a pretty hands-on sort of person. I like getting things done, and this is an environment where one person can have a big impact.
What do you think about working and living in La Serena?
La Serena is home. It’s small enough to have no pollution. It has easy access to the spectacular countryside. And it isn’t crowded except in the summer holidays (January-February). I live just out of town, with a view of the Cerro Tololo and Cerro Pachon domes. Culture, and all the advantages and disadvantages of a big city, can be found in Santiago, a five hour’s drive or a one hour flight away.