Supernova remnant SNR 0509-67.5 examined with Chandra

Using NASA’s Chandra X-ray Observatory, astronomers have performed an X-ray proper motion study of a supernova remnant known as SNR 0509-67.5. The research, published October 5 on arXiv.org, provides essential information to expand this structure.

Supernova remnants (SNRs) are diffuse, expanding structures that result from a supernova explosion. They contain ejected material, expanded by the explosion, and other interstellar material kicked up by the shock wave from the exploded star.

Studies of supernova remnants are important to astronomers because they play a key role in the evolution of galaxies, scattering the heavy elements produced in the supernova explosion and providing the energy needed to heat the interstellar medium. SNRs are also believed to be responsible for accelerating galactic cosmic rays.

SNR 0509-67.5 is a Type Ia supernova remnant in the Large Magellanic Cloud (LMC), discovered by an X-ray survey by the Einstein Observatory. Previous observations of this SNR have found it to be about 310 years old and expanding into a sparse environment at an average speed of about 7,500 km/s.

A team of astronomers led by University of Maryland Benson T. Guest continued to study the expansion process of SNR 0509-67.5. To do this, they analyzed the latest proper motion data on this SNR collected with Chandra in 2020.

“A new epoch of Chandra observations (PI: B. Williams) was acquired between April 11 and November 21, 2020 totaling 414 ks and spread over 14 individual segments of 25-40 ks in length,” they explained researcher.

First, Guest’s team measured the diameter of SNR 0509-67.5 using radial profiles along six regions, all crossing the geometric center of the remnant and spaced by rotations of 30 degrees. The new measurements were then compared to previous Chandra data from 2000 and 2007.

The measured change in diameter of SNR 0509-67.5 in six directions resulted in an average expansion rate of just over 6,120 km/s. According to the researchers, this corresponds to an unchecked age of about 600 years, making the true age of the remnant even lower.

“The average speed we calculated corresponds to an age of 600 years with unrestrained free expansion, although the real age is slightly lower. The velocity we measured agrees with the results of Hovey et al. (2015), who then used hydrodynamic simulations to calculate an age of 310 years,” the astronomers concluded.

The researchers added that their method does not allow them to determine whether one region of SNR 0509-67.5 is expanding faster than another. Further observations of this remnant are needed to verify this, for example with the Hubble Space Telescope (HST) in the optical band and Chandra at X-ray wavelengths.

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