NASA’s IXPE Sends First Science Image

IXPE’s first x-ray image is of Cassiopeia A, a supernova remnant from a star that exploded in the 17th century. Credit: NASA

In time for Valentine’s Day, NASA’s IXPE (Imaging X-Ray Polarimetry Explorer), which launched Dec. 9, 2021, has sent down its first science image to its mission operations center located at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder. This is the first official data retrieval since IXPE completed its month-long commissioning phase.

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.  

IXPE first focused its X-ray eyes on Cassiopeia A, an object consisting of the remains of a star that exploded in the 17th century. 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.

In the image, the saturation of the magenta color corresponds to the intensity of this light. A complementary image overlays high energy X-ray data, shown in blue, from NASA’s Chandra X-Ray Observatory. Chandra and IXPE, with different kinds of detectors, capture different levels of angular resolution, or sharpness. 

After Chandra launched in 1999, its first image was also of Cassiopeia A. Chandra’s X-ray imagery revealed, for the first time, that there is a compact object in the center of the supernova remnant, which may be a black hole or neutron star.

“The IXPE image of Cassiopeia A is as historic as the Chandra image of the same supernova remnant,” said Martin C. Weisskopf, the IXPE Principal Investigator based at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “It demonstrates IXPE’s potential to gain new, never-before-seen information about Cassiopeia A, which is under analysis right now.”

A key measurement that scientists will make with IXPE is called polarization, a way of looking at how X-ray light is oriented as it travels through space. The polarization of light contains clues to the environment where the light originated. IXPE’s instruments also measure the energy, the time of arrival, and the position in the sky of the X-rays from cosmic sources.  

Imma Donnarumma, an Italian Space Agency (ASI) Project Scientist, said:  “The IXPE observations of Cassiopeia A highlight the unique capabilities of the polarimeters aboard IXPE and open a new window on the X-ray Universe.”

Paolo Soffitta, the National Institute for Astrophysics (INAF) Italian Principal Investigator, declared: “The IXPE image of Cassiopeia A is bellissima, and we look forward to analyzing the polarimetry data to learn more on how this supernova remnant accelerates cosmic-rays.”

Luca Baldini, an IXPE co-investigator at Italy’s Universita’ di Pisa and National Institute for Nuclear Physics (INFN), said: “The observation of Cassiopea A marks the culmination of 20 years of research and development on the gas pixel detector that made IXPE possible, and the beginning of an exciting new phase in this adventure.”

With polarization data from Cassiopeia A, 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. Researchers are currently working with the data to create the first-ever X-ray polarization map of the object. This will reveal new clues about how X-rays are produced at Cassiopeia-A.

“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.”

IXPE launched on a Falcon 9 rocket from Cape Canaveral and now orbits 370 miles (600 kilometers) above Earth’s equator. The mission is a collaboration between NASA and the Italian Space Agency, with partners and science collaborators in 12 countries. Ball Aerospace, headquartered in Broomfield, Colorado, manages spacecraft operations. LASP, located at CU Boulder, manages the mission operations.

Original article can be found here.