So X-rays really show us that the universe
is very energetic.
We find X-rays in jets
erupting from the centers of active galaxies.
We use them to measure the spin of black holes
or supernova explosions.
It takes a powerful event
to produce cosmic X-rays.
Sometimes people also call it the hot universe
because, you know, when you have this gas
in galaxy clusters or also around galaxies that you can see only in X-rays.
This gas is about 10 million to 100 million degrees,
which is so hot that this gas does not radiate in the
optical, does not radiate in the infrared, but only radiates in X-rays.
To understand these hottest regions.
We need the next-generation X-ray
telescope.
The Japan Aerospace Exploration Agency, or JAXA, is partnering with NASA
and the European Space Agency to launch the next-generation
X-ray Space Telescope.
The telescope,
called XRISM, launches from the Tanegashima Space Center
at the southern end of Japan on an H-IIA
rocket.
The spacecraft weighs over 5,000
pounds, stands over 30 feet tall and will orbit
approximately 340 miles above Earth.
We're familiar with the medical uses of X-rays.
X-ray light is energetic enough to pass through our skin.
Our calcium dense bones absorb that light,
blocking it from reaching the detector and creating a shadow.
Luckily for us, X-rays
from space don't make it through our atmosphere.
But what that does mean is that we have to send X-ray
hunting missions into orbit to detect this high-energy
light.
XRISM also needs special kinds of mirrors,
which are built at NASA's Goddard Space Flight Center.
The type of the mirror is called nested mirror
that looks like a cross-section of an onion.
X-rays are
so energetic, they fly right through typical mirrors
For the visible light,
we typically place them like this, so that light just bounces back.
But for the X-rays, this doesn't work
so that we put the mirror like this,
so that X-rays just grazes the surface of the shell.
When they strike mirrors at very shallow angles,
X-rays, too, can bounce.
And then so we made it like a conical shell,
like this.
Then X-ray can be directed.
XRISM
has two instruments, each with their own mirror assembly,
one for imaging, called Xtend, the other for spectroscopy,
called Resolve.
JAXA built Xtend to provide XRISM with a wide
field of view. It can observe an area about 60% larger
than the average appearance size of the full moon.
NASA's Resolve instrument
is a spectrometer that splits X-ray light like a prism
so scientists can detect specific
elements present in the sources they're studying.
It uses a small six-by-six
pixel detector called a microcalorimeter, nestled
in a refrigerator-sized container of liquid helium.
Resolve will measure the small temperature changes
caused when X-rays hit one of those pixels.
To track such small temperature changes, Resolve’s
detectors must be kept extremely cold.
That liquid helium cryocooler will keep the instrument
at 0.05 degrees.
It's so cold
it is a fraction of a degree above
absolute zero.
Heat is simply a product of moving atoms
keeping Resolve’s detector that cold means that the atoms barely move.
So there's very little thermal noise in the system.
It's what keeps these accurate measurements
possible.
Each X-ray detected will help scientists pursue
many questions about the hottest regions of the cosmos.
What's happening
in the extreme gravitational fields around black
holes?
Can we discover
what is inside a neutron star?
How did some of the universe's largest structures
like galaxy clusters, evolve?
Optical Telescope,
you will just see galaxies everywhere.
If you if you look at this same cluster of galaxies in X-rays,
you will see actually a lot of gas.
And this gas constitutes actually most of the matter
the cluster of the galaxies, which is something it's important
to to understand, because it means that most of the matter
in the universe is not in the form of planets or stars,
but it's really in the form of this all of this gas. So.
But XRISM really has this capability of decomposing this X-ray light
in a way that's much, much more accurate than what has
ever been done before.