There have been no direct measurements of the strongest magnetic field in the universe until now, thanks to a team led by the Chinese Insight-HXMT spacecraft.
The greatest magnetic fields in the universe are produced by neutron stars, a fact well-known across the scientific community. Only by searching for cyclon resonance scattering signatures can one reliably and directly quantify these magnetic fields close to a neutron star’s surface (CRSF). The neutron star X-ray binary Swift J0243.6+6124 has a cyclotron absorption line with an energy of 146 keV, which correlates to a surface magnetic field of over 1.6 billion Tesla, according to the Insight-HXMT team.
Astrophysical Journal Letters reported the findings last month. Together with the Institute for Astronomy and Astrophysics at the Kepler Center for Astro and Particle Physics at the University of Tübingen’s Institute for High Energy Physics (IHEP), they were obtained.
Measurement using Insight-HXMT is no longer valid.
An earlier Insight-HXMT album is available.
X-ray binary system GRO J1008-57 has a surface magnetic field of 1 billion Tesla, which was measured by the Insight-HXMT team two years ago, setting a world record for the direct measurement of the universe’s greatest magnetism at the time. As time went on, Insight-HXMT discovered another record-setting absorption line from a different neutron star, 1A 0535+262.
It has been demonstrated time and time again that the astronomy satellite can study the energy spectrum. Finally, the previous record was beaten by a whopping 60%.
Resonant scattering may be the cause of cyclotron absorption lines.
There are two stars in an X-ray binary system that are neutron stars. An accretion disk forms as gas from the companion star descends toward the neutron star. The plasma in the accretion disk will then fall along magnetic lines to the neutron star’s surface, resulting in intense X-ray emission from the neutron star. The name “X-ray accretion pulsar” refers to the periodic X-ray pulse signals that come from these discharges.
Preliminary studies have shown that cyclotron absorption lines are present in the X-ray spectrum of pulsars. There is a possibility that resonant scattering and the subsequent X-ray absorption by electrons traveling through powerful magnetic fields are to blame for this.
Because the energy of the absorption structure is exactly proportional to the strength of the surface magnetic field, this phenomena can be used to determine the strength of the magnetic field near a neutron star’s surface.
The first and most reliable evidence
The X-ray luminosity of ultraluminous pulsars, objects that significantly outshine that of canonical pulsars, has already been found in various galaxies outside of our own.
While studying the Swift J0243.6+6124 X-ray pulsar, Insight-HXMT found a clear cyclotron absorption line, which was observed in great detail and over a large area. An electron cyclotron absorption line in an ultraluminous X-ray source has been detected for the first time, making this the highest magnetic field ever measured in the universe and the first observation of an electron cyclotron absorption line.
Insight-cyclotron HXMT’s absorption line-based direct measurement of the magnetic field is several orders of magnitude stronger than the indirect estimate. According to these findings, the magnetic field structure of neutron stars is more complex and nonsymmetric than previously thought.