The First Image From NASA’s new X-ray Observatory

It’s first light for one of the newest space observatories! The Imaging X-Ray Polarimetry Explorer team has released their first image, taken after a month-long commissioning phase for the spacecraft. And it’s a beauty.

IXPE looked at a favorite target among space observatories, the supernova remnant Cassiopeia A. While x-rays are invisible to human eyes, the amount of magenta color in this image corresponds to the intensity of X-ray light observed. Needless to say, it’s intense with high energy x-rays.  

For contrast, the team overlaid observations by another x-ray observatory, the Chandra X-Ray Observatory, which shows up as the veins of blue throughout the image. Chandra and IXPE have different types of detectors, and therefore capture different levels of angular resolution, or sharpness. Together, they can produce more complete and detailed data on high energy sources in the Universe.

The image is also a nod to the venerable Chandra observatory, as Cas A was Chandra’s first light image, as well. That mission launched in 1999 as NASA’s flagship mission for X-ray astronomy, and is still operating in a high Earth orbit.

Since Earth’s atmosphere absorbs the vast majority of X-rays, they are not detectable from Earth-based telescopes. Space-based x-ray telescopes have allowed for new discoveries and new understandings of our cosmos

This new image from IXPE contains data collected from January 11-18. The mission launched on December 9, 2021 on board a SpaceX Falcon 9 rocket from NASA’s Kennedy Space Center in Florida. IXPE was placed in an orbit around Earth’s equator at an altitude of approximately 372 miles (600 kilometers).

IXPE is a joint effort between NASA and the Italian Space Agency, and is the first space observatory dedicated to measuring the polarization of X-rays from some of the most fascinating and dynamic objects in the universe.

The team said all instruments are functioning well aboard the observatory, which is on a quest to study some of the most mysterious and extreme objects in the universe. 

Cassiopeia A is the shredded remains of a star that exploded several thousand years ago. It is the youngest known supernova remnant in our Milky Way Galaxy and resides 10,000 light-years away in the constellation Cassiopeia, so the star actually blew up 10,000 years before the light reached Earth in the late 1600s.

The shock waves from the explosion have swept up surrounding gas, heating it to high temperatures and accelerating cosmic ray particles to make a cloud that glows in X-ray light. Other telescopes have studied Cassiopeia A before, but IXPE will allow researchers to examine it in a new way. The team is currently analyzing all the data to learn more, according to Martin C. Weisskopf, the IXPE principal investigator, in a press release.

For example, IXPE will allow scientists to see, for the first time, how the amount of polarization varies across the supernova remnant, which is about 10 light-years in diameter.

“IXPE’s future polarization images should unveil the mechanisms at the heart of this famous cosmic accelerator,” said Roger Romani, an IXPE co-investigator at Stanford University. “To fill in some of those details, we’ve developed a way to make IXPE’s measurements even more precise using machine learning techniques. We’re looking forward to what we’ll find as we analyze all the data.”

Lead image caption: This image of the supernova remnant Cassiopeia A combines some of the first X-ray data collected by NASA’s Imaging X-ray Polarimetry Explorer, shown in magenta, with high-energy X-ray data from NASA’s Chandra X-Ray Observatory, in blue.Credits: NASA/CXC/SAO/IXPE