Learn how the NASA/JAXA X-ray Imaging and Spectroscopy Mission (XRISM) will study the 'X-ray Cosmos' in this explainer from the Goddard Space Flight Center.
Credit: NASA/Goddard Space Flight Center.
Credit: NASA/Goddard Space Flight Center.
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TechTranscript
00:00 So X-rays really shows us that the universe is very energetic.
00:07 We find X-rays in jets, erupting from the centers of active galaxies.
00:15 We use them to measure the spin of black holes or supernova explosions.
00:23 It takes a powerful event to produce cosmic X-rays.
00:29 Sometimes people also call it the hot universe,
00:32 because when you have this gas in galaxy clusters or also around galaxies that you can see only in X-rays,
00:38 this gas is about 10 million to 100 million degrees,
00:41 which is so hot that this gas does not radiate in optical, does not radiate in infrared,
00:47 but it only radiates in X-rays.
00:49 To further understand these hottest regions, we need the next generation X-ray telescope.
00:58 The Japan Aerospace Exploration Agency, or JAXA,
01:02 is partnering with NASA and the European Space Agency
01:06 to launch the next generation X-ray space telescope.
01:11 The telescope, called KRISM, launches from the Tonigashima Space Center
01:19 at the southern end of Japan on an H-2A rocket.
01:25 The spacecraft weighs over 5,000 pounds, stands over 30 feet tall,
01:31 and will orbit approximately 340 miles above Earth.
01:35 We're familiar with the medical uses of X-rays.
01:41 X-ray light is energetic enough to pass through our skin.
01:45 Our calcium-dense bones absorb that light,
01:49 blocking it from reaching the detector and hitting the object.
01:53 Blocking it from reaching the detector and creating a shadow.
01:57 Luckily for us, X-rays from space don't make it through our atmosphere.
02:03 But what that does mean is that we have to send X-ray hunting missions
02:07 into orbit to detect this high-energy light.
02:11 KRISM also needs special kinds of mirrors,
02:17 which are built at NASA's Goddard Space Flight Center.
02:21 One type of the mirror is called a nested mirror.
02:24 It looks like a cross-section of an onion.
02:28 X-rays are so energetic, they fly right through typical mirrors.
02:40 For the visible light, we typically place the mirror like this,
02:44 so that light just bounces back.
02:46 But for the X-rays, this doesn't work,
02:49 so that we put the mirror like this,
02:52 so that X-rays just graze the surface of the shell.
02:57 When they strike mirrors at very shallow angles,
03:02 X-rays too can bounce.
03:04 And so we made it like a conical shell, like this,
03:11 then X-rays can be directed.
03:14 [Music]
03:19 KRISM has two instruments, each with their own mirror assembly.
03:24 One for imaging, called Xtend,
03:26 the other for spectroscopy, called Resolve.
03:30 JAXA built Xtend to provide KRISM with a wide field of view.
03:37 It can observe an area about 60% larger
03:42 than the average apparent size of the full moon.
03:45 NASA's Resolve instrument is a spectrometer
03:51 that splits X-ray light, like a prism,
03:54 so scientists can detect specific elements
03:57 present in the sources they're studying.
03:59 It uses a small 6x6 pixel detector,
04:03 called a microcalorimeter,
04:06 nestled in a refrigerator-sized container of liquid helium.
04:11 Resolve will measure the small temperature changes
04:15 caused when X-rays hit one of those pixels.
04:18 To track such small temperature changes,
04:21 Resolve's detectors must be kept extremely cold.
04:25 That liquid helium cryocooler
04:28 will keep the instrument at 0.05 degrees Kelvin.
04:33 It's so cold,
04:36 it is a fraction of a degree above absolute zero.
04:41 Heat is simply a product of moving atoms.
04:45 Keeping Resolve's detector that cold
04:48 means that the atoms barely move.
04:51 So there's very little thermal noise in the system.
04:55 It's what keeps these accurate measurements possible.
05:01 Each X-ray detected will help scientists pursue
05:05 many questions about the hottest regions of the cosmos.
05:09 What's happening in the extreme gravitational fields
05:13 around black holes?
05:16 Can we discover what is inside a neutron star?
05:26 How did some of the universe's largest structures,
05:30 like galaxy clusters, evolve?
05:34 In an optical telescope, you will just see galaxies everywhere.
05:38 If you look at this same cluster of galaxies in X-rays,
05:42 you will see actually a lot of gas.
05:44 And this gas constitutes actually most of the matter
05:47 in the cluster of the galaxies,
05:49 which is something extremely important to understand
05:52 because it means that most of the matter in the universe
05:55 is not in the form of planets or stars,
05:57 but it's really in the form of this gas.
06:00 But CRISM really has this capability of decomposing
06:04 this X-ray light in a way that's much, much more accurate
06:07 than what has ever been done before.
06:10 [Music]
06:13 [Music]
06:17 [Music]
06:20 (gentle music)
06:22 [MUSIC]