NASA’s Chandra captures a pulsar in an X-ray radar trap

• a[{“ attribute=““>pulsar is racing through the debris of an exploded star at a speed of over a million miles per hour.
• To measure this, researchers compared NASA Chandra X-ray Observatory images of G292.0+1.8 taken in 2006 and 2016.
• Pulsars can form when massive stars run out of fuel, collapse, and explode — leaving behind a rapidly spinning dense object.
• This result may help explain how some pulsars are accelerated to such remarkably high speeds.

The G292.0 + 1.8 supernova remnant contains a pulsar moving at over a million miles per hour. This image includes data from NASA’s Chandra X-ray Observatory (red, orange, yellow, and blue) used in this discovery. The X-rays are combined with an optical image from the Digitized Sky Survey, a ground-based survey of the entire sky.

Pulsars spin fast neutron stars They can form when massive stars run out of fuel, collapse and explode. These explosions sometimes create a “kick” that causes this pulsar to race through the remnants of the supernova explosion. The inset shows a close-up of this pulsar in X-ray images from Chandra.

To make this discovery, the researchers compared Chandra images of G292.0 + 1.8 taken in 2006 and 2016. A pair of complementary images show the change in the pulsar’s position over the course of 10 years. The shift in the source location is negligible because the pulsar is about 20,000 light-years away from Earth but has traveled about 120 billion miles (190 billion km) in that time period. The researchers were able to measure this by combining high-resolution Chandra images with micro-technology to verify the coordinates of the pulsar and other X-ray sources using precise positions from the Gaia satellite.

Pulsar sites, 2006 and 2016. Credit: X-ray: NASA/CXC/SAO/L. Shi et al.

The team calculated that the pulsar was moving to the left from the center of the supernova remnant at at least 1.4 million miles per hour. This speed is about 30% faster than the previous estimate of the pulsar’s velocity, which was based on an indirect method of measuring how far the pulsar is from the center of the explosion.

The newly determined velocity of the pulsar suggests that G292.0 + 1.8 and the pulsar could be much smaller than astronomers previously thought. The researchers estimate that G292.0 + 1.8 may have erupted about 2,000 years ago as seen from Earth, rather than 3,000 years ago as previously calculated. This new estimate of G292.0 + 1.8’s age is based on extrapolating the pulsar’s position in the past to coincide with the center of the explosion.

Several civilizations around the world were recording supernova explosions at the time, opening up the possibility of direct observation of G292.0 + 1.8. However, G292.0 + 1.8 is below the horizon for most Northern Hemisphere civilizations that you may have observed, and there are no recorded examples of a supernova observed in the Southern Hemisphere towards G292.0 + 1.8.

Close-up of the Chandra image center of the G292 + 1.8. The direction of motion of the pulsar (arrow) and the location of the blast center (green oval) based on movement of debris visible in the optical data are shown. The position of the pulsar was extrapolated 3000 years ago and the triangle shows the uncertainty in the extrapolation angle. Matching the location of the induction to the epicenter of the explosion gives an age of approximately 2,000 years for the pulsar and G292 + 1.8. The center of mass (intersection) of the X-ray elements (Si, S, Ar, Ca) detected in the debris is located opposite the center of the explosion of a moving pulsar. The asymmetry in the debris in the upper right corner of the explosion pushed the pulsar down to the left while maintaining momentum. Image credit: X-ray: NASA/CXC/SAO/L. Shi et al.; Optical: Palomar DSS2

In addition to learning more about G292.0 + 1.8’s age, the research team also studied how the pulsar’s supernova kicked off its powerful kick. There are two main possibilities, both of which are that the material from the supernova is not being ejected evenly in all directions. One possibility is that neutrinos The ejector in the explosion is ejected asymmetrically from the explosion, the other is that the debris from the explosion is ejected asymmetrically. If matter had a preferred orientation, the pulsar would be pushed in the opposite direction, due to a physical principle called conservation of momentum.

The amount of neutrino asymmetry needed to explain the high speed in this last result would be severe and support the interpretation that the asymmetry in the debris from the explosion gave the pulsar its kick.

The energy transferred to the pulsar from this explosion was enormous. Although the pulsar is only about 10 miles wide, the pulsar has a mass of 500,000 times the mass of the Earth and is moving 20 times faster than the speed of the Earth orbiting the sun.

https://www.youtube.com/watch?v=0itTriYIOlI

The latest work by Xi Long and Paul Plucinksky (Astrophysics Center | Harvard & Smithsonian) on G292.0 + 1.8 was presented at the 240th Meeting of the American Astronomical Society in Pasadena, California. The results are also discussed in an article accepted for publication in the Astrophysical Journal. The other authors of the paper are Daniel Patno and Terence Gaetz, both from the Center for Astrophysics.

Reference: “Correct motion of pulsar J1124-5916 in the galactic supernova remnant G292.0 + 1.8” by Xi Long, Daniel J. Patnaude, Paul P. Plucinsky, and Terrance J. Gaetz, Accepted, Astrophysical Journal.
arXiv: 2205.07951

NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts and flight operations from Burlington, Massachusetts.