New, detailed look at Crab Nebula reveals more of its inner workings

Using NASA’s Imaging X-ray Polarimetry Explorer (IXPE), scientists have created a detailed, nuanced map of the Crab Nebula, revealing more about its donut-shaped magnetic field's inner workings than ever before.

Located approximately 6,500 light-years away from Earth, the Crab Nebula is a well-studied cosmic object that resulted from a supernova documented in the year 1054. The massive star's explosion left behind a dense object called the Crab Pulsar. With as much mass as about two Suns, the pulsar emits gases, shock waves, magnetic fields and high-energy light and particles, creating a bizarre environment that is yet to be thoroughly understood.

"The Crab is one of the most-studied high-energy astrophysical objects in the sky. So it is extremely exciting that we could learn something new about this system by looking through IXPE's polarized lenses," said Michela Negro, a research scientist at NASA Goddard Space Flight Center affiliated with the University of Maryland, Baltimore, and a co-author of the study.

While Crab Nebula's magnetic field resembles that of the Vela Pulsar Wind Nebula, the magnetic field turbulence in Crab was found to be more patchy and asymmetrical than expected, which was surprising to scientists.

In the 1970s, Weisskopf, now an emeritus astronomer at NASA's Marshall Space Flight Center in Huntsville, Alabama, and his colleagues measured X-ray polarization from the Crab Nebula to understand its extreme environment and found that Crab has an average polarization of about 20%.

IXPE's measurements of polarization across the entire nebula were about the same as those made by Weisskopf and colleagues. However, the advanced capabilities of IXPE allowed for a more precise determination of polarization angles and enabled the study of variations in polarization throughout the nebula. The outer parts of the nebula exhibited much higher levels of polarization than areas closer to the pulsar where polarization was lower, according to the IXPE data.

The findings indicate that the X-rays in the Crab Nebula originate from the outer magnetic field region, known as the "wind" region. However, the exact location and mechanism of this process are yet to be determined.

Nebula's nuancesA supernova documented in 1054 created the Crab Nebula. A new look reveals more of the inner workings amid the chaos of gases, shock waves, magnetic fields and high-energy light and particles coming from the rotating pulsar. https://t.co/bR9tf95WUL pic.twitter.com/33UsVy3u6V

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