First historical image captured by the new X-ray space telescope
Located 11,000 light-years away, it is the expanding remnant of a star thought to have been observed to explode in the 1690s, and is one of the most well-studied objects in the Milky Way, for good reason: has provided some valuable insight into supernovae.
Cassiopeia A emits light in multiple wavelengths, including radio, optics and, of course, X-rays. Indeed, the first scientific image from another X-ray observatory NASA X, Chandra, was also from Cassiopeia A. But IXPE is showing us the object in a way we have never seen before.
“Cassiopeia A's IXPE image is as historic as the 'Chandra image of the same supernova remnant, ”said the astronomer and researcher and IXPE principal Martin C. Weisskopf of NASA's Marshall Space Flight Center. “It demonstrates the potential of IXPE to obtain new information never before seen on Cassiopeia A, which is being analyzed right now.”
There is a lot to study on Cassiopeia A. Before dying, the star Forerunner was a massive object that, when it ran out of fuel, became unstable, ejecting its outer layers to create a cloud of circumstellar material. When the supernova finally took place, therefore, the shock wave was not entering pristine space, but in a relatively dense cloud.
The shocks and magnetic fields that emerge from this intense environment can create synchrotrons that accelerate electrons, generating high-energy X-rays. The combination of Chandra's data with light in other wavelengths allowed astronomers to map the different elements in Cassiopeia A that were emitted during the giant explosion.
Credits: NASA / ESA IXPE is specifically designed to study how X-rays are polarized. When light is emitted from a source, its waves are oriented in all directions. When that light meets a medium, it can change. Passing through the gas, for example, can absorb some orientations. Bouncing on things can also alter the orientation of some wavelengths. We call this polarization effect.
For an object like Cassiopeia A, the detailed polarization data will tell us more about the environment within the supernova remnant. It will reveal more information about how light is absorbed and reflected and the tangle of magnetic fields produced by a supernova.
"Future IXPE polarization images should unravel the mechanisms at the heart of this famous cosmic accelerator," he said astronomer Roger Romani of Stanford University.
“To complement some of these details, we have developed a way to make IXPE measurements even more accurate using machine learning techniques. We can't wait to see what we find as we analyze all the data. ”
The telescope, from its position in low Earth orbit, also probes the polarization of X-rays from some of the most energetic sources of the Milky Way and of the larger Universe. This includes neutron stars, pulsars, magnetars, black holes and quasar galaxies that glow with one of the most intense lights in the Universe. IXPE will also map light intensity, arrival time and position in the sky.
Cassiopeia A is an excellent starting point. “The IXPE image of Cassiopeia A is beautiful,” said astronomer and principal investigator of IXPE Paolo Soffitta of the National Institute of Astrophysics (INAF) in Italy, “and we can't wait to analyze the polarimetric data to find out more about this supernova remnant ".
