My specialty is black holes, especially the supermassive black holes at the centers of galaxies. We know they grew over cosmic time as the galaxy was forming around them. My research is looking at when they grew, by how much, and what effect the energy release had on the surrounding galaxy.
ASTRO-H has a very clever detector system that captures even the very high-energy X-rays. Many cosmic sources, not just black holes, but many others – galaxies, stars, neutron stars, pulsars – radiate X-rays that have high enough energies to penetrate the surrounding gas and dust. These high-energy x-rays have high penetrating power, so it is difficult to reflect them with a telescope – it’s difficult to catch them. ASTRO-H is capable of detecting those X-rays that are difficult to catch. And because of that we’ll see objects that were hidden from previous X-ray satellites.
ASTRO-H can determine what kind of material is near the black hole, what its temperature is, even what its motion is around the black hole. And that is a brand-new capability that will probably tell us a great deal about how and when supermassive black holes grow. I’m also very interested in hidden black holes. With ASTRO-H, I think we can do a new census that will find even the most hidden black holes. For me, that’s a very interesting thing to look for.
ASTRO-H has capabilities never before seen on any other satellite from the U.S., from Europe, anywhere. It’s really breaking new ground. ASTRO-H has, for my interest, several very important capabilities. Probably the most important is its new high-resolution spectrometer. This means that not only does it detect X-rays from distant sources, including black holes, but it determines the energy of each X-ray very precisely. I think this new high-resolution spectrometer will open up a new research field.
In 1987 I visited ISAS [now part of JAXA] to work on the Japanese X-ray Astronomy Satellite GINGA. It was my first time working with Japanese scientists. At the time, the Japanese X-ray astronomy community was tiny. But now, Japanese X-ray astronomy satellites have made really very important contributions to understanding different parts of the universe. Astronomers around the world pay attention to these satellites. And now, I would say Japanese X-ray Astronomy is probably the strongest in the world.
Astronomy is just fun for me. I think it’s very interesting to learn new things, and to answer questions nobody could answer before. How did I get interested in astronomy? When I was a student, I had a chance to do some research in astronomy. I discovered that you could learn about the universe from just a few pieces of light. You could learn what had happened over vast distances and enormously long times ago. I thought it was really fascinating – kind of like archeology, but instead of using a shovel we used a telescope. Every one of us asks, “What’s up there? What’s out there? What’s beyond our world?” And astronomy is searching for those answers. Everyone is interested in the birth of the universe, how the universe has evolved up to today. I hope that ASTRO-H will solve mysteries of the universe.
