Saturday, January 22

Top 10 Iconic Moments in NASA Communications and Navigation in 2021

image

Do you believe X-ray vision is an ability exclusively seen in comic books and movies? Thanks to the X-ray observatories we’ve deployed into space, NASA has it for real, unlike Superman and Supergirl.

The Imaging X-ray Polarimetry Explorer, or IXPE for short, has now launched into space to help us improve our superpower!

Meet IXPE

image

Dentists utilize an X-ray machine that creates X-rays and catches them on a device on the opposite side while taking X-ray photos of a tooth. However, X-rays can also be found in nature. In astronomy, we study faraway objects’ X-rays to learn more about them.

IXPE will improve astronomers’ understanding of some of these objects, such as black holes, neutron stars, and supernova-produced expanding clouds.

This is because it will gather data on X-ray light that has only been observed from space on a few occasions!

image

By monitoring three attributes of light — when it arrives, where it comes from, and what energy it has – X-ray astronomers have learnt a lot about the cosmos (think: colors). Consider these traits to be three of a pyramid’s four sides. A property known as polarization is the missing piece.

The polarization of light informs us how well it is organized. This provides astronomers with more information on how X-rays are created and what stuff they pass through on their approach to us. IXPE will investigate a previously unknown aspect of cosmic X-ray sources.

What is polarization?

image

From microwaves to gamma rays, all light is made up of two waves traveling together, one carrying electricity and the other carrying magnetism. These two waves always vibrate at 90° to each other, with their peaks and valleys in sync, and they also vibrate at 90° to their motion direction.

We’ll only show one of these waves, the one that carries electricity, to keep things simple. We’d see something like the animation above if we could zoom in on a standard beam of light. With all the wave peaks pointing in different directions, it’s a jumble.

image

When light interacts with matter, it can become better organized. Its electric field can vibrate in a way that keeps all the wave crests pointing in the same direction, as shown above. This is polarized light.

The amount and type of polarization we detect in light tell us more about its origin, as well as any matter it interacted with before reaching us.

Let’s look at the kinds of objects IXPE will study and what it may tell us about them.

Exploring star wrecks

image

Exploded stars create vast, rapidly expanding clouds called supernova remnants – like the Jellyfish Nebula above. It formed 4,000 years ago, but even today, the remnant’s heart can tell us about the extreme conditions following the star’s explosion.

X-rays give us a glimpse of the powerful processes at work during and after these explosions. IXPE will map remnants like this, revealing how X-rays are polarized across the entire object. This will help us better understand how these celestial cataclysms take place and evolve.

Magnifying supermagnets

image

Some supernovae leave behind neutron stars. They form when the core of a massive star collapses, squeezing more than our Sun’s mass into a ball only as wide as a city.

The collapse greatly ramps up their spin. Some neutron stars rotate hundreds of times a second! Their magnetic fields also get a tremendous boost, becoming trillions of times stronger than Earth’s. One type, called a magnetar, boasts the strongest magnetic fields known – a thousand times stronger than typical neutron stars.

These superdense, superspinning supermagnets frequently erupt in powerful outbursts (illustrated above) that emit lots of X-rays. IXPE will tell astronomers more about these eruptions and the extreme magnetic fields that help drive them.

Closing in on black holes

image

Black holes can form when massive stars collapse or when neutron stars crash together. Matter falling toward a black hole quickly settles into a hot, flat structure called an accretion disk. The disk’s inner edge gradually drains into the black hole. Notice how odd the disk appears from certain angles? This happens because the black hole’s extreme gravity distorts the path of light coming from the disk’s far side.

X-rays near the black hole can bounce off the disk before heading to our telescopes, and this polarizes the light. What’s exciting is that the light is polarized differently across the disk. The differences depend both on the energies of the X-rays and on what parts of the disk they strike. IXPE observations will provide astronomers with a detailed picture of what’s happening around black holes in our galaxy that can’t be captured in any other way.

By tracking how X-ray light is organized, IXPE will add a previously unseen dimension to our X-ray vision. It’s a major upgrade that will give astronomers a whole new perspective on some of the most intriguing objects in the universe.