In recent blogs, I introduced you to Benne Holwerde, a researcher at the University of Cape Town in South Africa. He’s on a team of scientists building a new radio telescope called MeerKAT (Karoo Array Telescope). Holwerde and his group hope MeerKAT will solidify South Africa as the host site for the Square Kilometre Array (SKA), an even-larger radio telescope. The SKA will be the world's biggest radio telescope, and it will be built in either South Africa's Northern Cape province (with outstations elsewhere in the country and spread across eight other African countries) or in Australia (with, possibly, outstations in New Zealand).
Here’s another report on the project from Holwerde.
SKA continuum conference
Recently we had a grand get-together of big names in astronomy here in Cape Town. There were a lot of high-level policy meetings about the Square Kilometre Array (SKA). I did not go to all of these, but there was a science conference in the mix as well, and I was definitely attending that. The meeting focused on one of the types of science we will be able to do with the SKA and its pathfinder projects MeerKAT and ASKAP: the radio continuum, which includes emission all across the radio spectrum due to highly energetic electrons.
Radio continuum is not my area of interest in radio astronomy — I study the 21-centimeter emission line of hydrogen — but it is very relevant for the eventual design trade-offs that will happen with both the SKA and the pathfinders. That discussion was happening in part during the coffee breaks, lunches, and dinners.
It is a hard call to make. The telescopes are put in a specific pattern. The array’s efficiency at observing the hydrogen emission or the radio continuum depends on the pattern of dishes. After the dishes have been put in place, it is nearly impossible to redesign the pattern. There were many talks and discussion emphasizing that we need to get it right initially.
Talks centered on the type of science that is on the horizon with such big radio telescopes. One of them was given by a friend of mine, Erik Murphy, now at Caltech. He did his Ph.D. on the relation between radio continuum and far-infrared emission, both the result of newly forming stars. The relationship is so tight that it will be worthwhile to track the rate galaxies were forming stars in the earlier universe with radio continuum emission. We really don’t know when and where most of the stars in a galaxy were made. Far-infrared observations of the distant universe are hard to obtain. You need space missions for those. But we might be able to use the SKA to probe star formation in the earlier universe based on the radio emission.
Some other possible science had crept into the talks as well. Recently, pulsar timing has emerged as a possible way to check Einstein’s general theory of relativity in extreme environments. Very cool science.
There was also a talk about using the information in the 21-cm emission line together with new NASA and ESA missions such as the Herschel Space Telescope. I would have cheered the guy on a little more, except that I think he also proposed to look at several places in the Northern Hemisphere. Oops. All the radio telescopes we were talking about are in the Southern Hemisphere.
And then there was the dinner. We bussed out to the wine lands near Cape Town (only 30 minutes or so, traffic permitting) and dined with the whole conference at Spier, one of the biggest wineries there. Going to a wine farm for wine tasting and lunch is one of my favorite things to do here. My rule is the smaller the winery, the better — but if you’ve got 150 or so people, Spier was a good way to go. This is South African cuisine at its best. Great if you like meat, especially game.
One of Spier’s gimmicks is a lady that gives you African face paint (lots of little dots), so that explains the photo of me here. The joke of the evening was that everyone had a different telescope design on his or her face. A prerequisite to a good conference is good food (and coffee) and this SKA 2009 Continuum Workshop was a great success (both culinary and scientific).
So there are these three almost completely different science topics we will be able to do with these telescopes as soon as they are built — 21 cm hydrogen, radio continuum science, and pulsar timing. The big discussion now is how do we configure the telescope so it can accommodate all three pursuits. I’ll hear more about that soon, I expect, because the first foundations for KAT-7 (the first seven dishes of MeerKAT) have already been poured.
Previous posts:
Our man in Cape Town II: What science could MeerKAT do?
Our man in Cape Town: Benne Holwerda wants to build the biggest radio telescope in history