Title: Astronomers Unravel Mystery Behind Erratic Behavior of Pulsar PSR J1023+0038
Subtitle: Multi-Wavelength Study Reveals the Cause of Intense Brightness and Dimming Cycles
Date: April 15, 2023
Scientists have made a groundbreaking breakthrough in understanding the strange behavior of pulsar PSR J1023+0038. This pulsar, located in a close binary system with another star, has been observed to switch from intensely bright “high mode” to dimmer “low mode” as it strips material from its companion star. The recent study, conducted by an international team of astronomers, has shed light on the cause behind this puzzling phenomena.
Pulsars are the remnants of massive stars that have gone supernova. These spinning neutron stars emit jets of electromagnetic radiation, making them appear to flash regularly when observed from Earth. PSR J1023+0038, classified as a millisecond pulsar due to its rapid rotation, gets its speed from stripping material off its companion star, drawing in and feeding off the energy.
The researchers discovered that the material stripped from the companion star forms an accretion disk around the pulsar. This disk is filled with highly energetic charged particles that are pulled inward by the pulsar’s gravity. At times, an unusually large amount of material can spiral closer to the pulsar, resulting in collisions between charged particles and the powerful winds of the pulsar. This interaction heats up the matter and pushes it outward, leading to intense brightness or “high mode”.
During high mode, the pulsar may also experience flares and erupt with plasma, emitting X-rays, ultraviolet, and visible light in an explosive flash. However, after this intense phase, the material blown off causes a significant decrease in emissions, including the pulsar wind. The synchrotron emissions, which power the compact jet responsible for consistent pulsing, pause temporarily as the jet is deprived of material.
The dimmer pulsar does continue to emit radio waves, primarily from the compact jet. Leftovers from the high mode ejecta can be observed during low mode, further confirming the presence of the pulsar’s emissions. Eventually, as new material approaches the pulsar, the cycle begins anew, with the influx of material filling in the spaces left by previously ejected plasma and reigniting the synchrotron emissions.
The investigation into this mysterious behavior required the collaboration of 12 ground-based and space telescopes, including the Atacama Large Millimeter/submillimeter Array (ALMA), ESO’s New Technology telescope, ESO’s Very Large Telescope, and ESA’s XMM-Newton X-ray telescope. This extensive multi-wavelength study delved into the interactions between inflowing material, winds, and overall pulses of the pulsar.
While this study sheds light on the behavior of pulsar PSR J1023+0038, it also raises questions about the similarities between transitional millisecond pulsars and black holes. The researchers highlight the need for further research to deepen our understanding of accretion physics in compact objects and explore potential connections between these two enigmatic phenomena.
As scientists continue to unravel the mysteries of the universe, it is the hope that further revelations will emerge, offering a clearer understanding of the processes and behaviors that occur within these celestial entities.