When Luigi Gallo graduated from the University of Calgary with a science degree 20 years ago, he did the conventional thing and got a job in the oil and gas industry.
It didn’t last. He realized he was after energy production on a far grander scale and was soon back in school earning his PhD in astrophysics.
That’s when Dr. Gallo fell under the spell of supermassive black holes, remote and powerful monsters that lurk in the hearts of distant galaxies, where gravity, density, temperature and magnetic fields are all off the charts compared with anything we know on Earth.
“We’re really talking about physics at the extremes,” he said. “Things that could never be duplicated in any laboratory.”
Now Dr. Gallo is poised to unravel the mysteries of black holes and related phenomena using a Japanese space telescope that will peer at the universe with a well-tuned X-ray eye.
The telescope, dubbed ASTRO-H until it is successfully deployed and rechristened with a more memorable name, is scheduled to lift off from Japan’s Tanegashima Space Center on Feb. 12. With the launch just one week away, anticipation – and apprehension – are building.
“It’s like being on a roller-coaster to be quite honest,” said Dr. Gallo, a professor of astronomy at St. Mary’s University in Halifax and principal investigator for Canada’s contribution to ASTRO-H. “It’s exciting to envision what it’s going to be like, but then I think of all the dangers related to taking something you’ve worked on for the past 10 years and basically strapping it to a bomb.”
Assuming all goes well at launch, the mission`s success will depend on a Canadian-built laser system that can measure the exact positions of the 12-metre-long telescope`s opposite ends down to two widths of a human hair, and constantly adjust for slight changes less than one-hundredth that size.
“We were able to push the envelope in terms of precision,” said Stéphane Gagnon, vice-president of programs for Neptec Design Group in Ottawa and lead engineer for the device, known as the Canadian Astro-H Metrology System. The system accounts for the bulk of Canada’s $10-million contribution to the mission.
Precision optics are essential for X-ray astronomy because X-rays have wavelengths far shorter than those of visible light. X-rays also pack much more punch and cannot be focused by a standard telescope lens or mirror – they just pass right through. But like stones skipping off the surface of a pond, X-rays hitting a polished metal surface at a glancing angle can be slightly redirected. X-ray telescopes exploit this effect by using tapered metal cylinders to gently funnel X-rays toward a detector. The more energetic the X-rays, the farther away from the cylinders the detector must be positioned.
ASTRO-H will study the most energetic X-rays in the universe, which means is has to be longer than any X-ray telescope ever built – so long that it won’t stretch out to its full size until it’s already in space. The Canadian system will be crucial for allowing astronomers to compensate as the telescope flexes and vibrates ever so slightly while orbiting the Earth.
A key feature of the telescope is its exquisite spectral resolution – the ability to discern between X-rays of slightly different energy, “like seeing fine shades within the colours of the rainbow,” said Dr. Gallo. This can be used to determine both the composition and motion of material giving off X-rays, including in places that have previously been hard to study, like the high-temperature environments surrounding supermassive black holes.
Dr. Gallo and his colleagues will have a year to work with ASTRO-H data before they are released more widely. Canadian astronomers who are not science team members will also be able to compete for a share of Japan’s reserved time on the telescope.
“Astro-H is a very exciting mission with unique capabilities… I am sure I will want to use it,” said Vicky Kaspi, a McGill University astrophysicist who studies pulsars, rapidly spinning stellar objects that emit X-ray pulses like distant lighthouse beacons.
Stéphane Desjardins, acting director for space exploration development at the Canadian Space Agency, said the mission showed off Canada’s strengths in advanced optics and would be a boon to the country’s growing community of X-ray astronomers.Report Typo/Error