David Saint-Jacques : ASTRO-H is a Japanese X-ray telescope based on a satellite in space. So, that allows us to look at the universe in X-rays. So what does that mean?
Ever since the dawn of mankind, we’ve been looking at the sky with our eyes and then we got curious and we wondered how we can look at it in different colours that our eyes can’t see. We used infrared light, because there’s a lot of infrared light coming from the sky. In ultraviolet also, we can see whole new things in ultraviolet when we look at the sky. And then we’ve been using microwaves, looking at the sky in microwaves, radio waves, and then more recently, we’re using X-rays. The same X-rays that are used in hospitals to figure out if you have a fracture, but there are celestial bodies that emit X-rays. X-rays are super high-energy radiation and they’re only emitted by high-energy events. So it’s the most exciting, catastrophic things that emit X-rays such as the death of stars, that massive explosion, or if you have a black hole gobbling everything around it, or the centre of galaxies. These things emit X-rays in the sky; they’re sources of X-rays in the sky. So we’ve had a few space-borne telescopes like that measuring X-rays over the last couple of decades. But so far, they’ve always been a little bit crude, so to speak, meaning very big pixels, only one colour, so kind of a black-and-white, big pixels image. It’s good, but not as good as ASTRO-H. ASTRO-H is going to be high-definition, colour image. Colour meaning, we’re going to measure X-rays of different frequencies, thanks to what we call the spectrometer, that can split the X-rays at different frequencies, and we’re going to have very precise pointing, so we can have very small pixels in our image. So that will teach us a whole lot more about the X-ray universe, meaning about the high-energy things in the universe.
As for Canada, what have we done in this project? So this project is a big teamwork, like a cooperative. In exchange for our scientists to have access to the data, we had to contribute something to the telescope itself. Our contribution is called a metrology system. This telescope is huge; it needs to be very big for the detection of X-rays to work. It’s too big to fit in the rocket. So, it was folded up for launch and then hurtled into orbit and then it deploys in space. But as you can imagine, when these things deploy, they are kind of lanky and they tend to bend and twist and shake and with the heat of the sunlight they cool down, warm up, they kind of warp and so they don’t stay straight. That’s very bad for a telescope to warp and not stay straight. So we contributed a system that measures how straight the telescope is. If it’s warped, twisted, bent, all of that so that we can figure out ways to improve the image and then get the perfect X-ray image that we’re seeking.
And that way, we’re kind of opening a new window on the universe, looking at it in very high resolution in X-rays.