Indian Scientists Discover Hidden Accretion Structure Around Bright X-Ray Pulsar
New Delhi — Researchers at India’s Raman Research Institute (RRI) have uncovered new evidence that Centaurus X-3, one of the brightest known X-ray pulsars, draws material from its companion star through an accretion disk, offering fresh insights into the behavior of highly magnetized neutron stars.
The discovery was made by a research team led by Kinjal Roy at RRI, an autonomous institution under India’s Department of Science and Technology, according to a statement issued Wednesday by the Ministry of Science and Technology.
The findings could help scientists develop more accurate models of Centaurus X-3, one of the most extensively studied binary pulsar systems, and improve understanding of how neutron stars interact with nearby stellar companions.
Centaurus X-3 is a high-mass X-ray binary system located approximately 24,000 light-years from Earth in the constellation Centaurus. It contains a highly magnetized neutron star orbiting a massive companion star more than 10 times the mass of the Sun.
The system was among the first X-ray pulsars discovered and has attracted scientific attention because of its exceptionally strong X-ray emissions.
Neutron stars are extraordinarily dense remnants of massive stars that have undergone gravitational collapse. They can contain a mass comparable to that of the Sun compressed into a sphere roughly the size of a major city.
In X-ray binary systems, the neutron star’s powerful gravitational field pulls material from its companion, causing matter to accumulate around or flow toward the compact object.
“In an X-ray binary, the pulsar’s extreme gravity pulls in material ejected by its companion star, and the pulsar starts accreting material from it, shooting out X-rays in the process,” the ministry explained.
As a pulsar rotates, radiation emitted from its magnetic poles sweeps through space, producing signals that can be detected by astronomical observatories.
This radiation, known as primary emission, also interacts with matter surrounding the neutron star.
Nearby structures can absorb and re-emit portions of the radiation, generating secondary emissions that provide valuable information about the pulsar’s environment.
By analyzing these secondary signals, astronomers can investigate the physical characteristics of the system, including its orientation, magnetic field strength and the distribution of surrounding matter.
The RRI researchers closely examined four secondary emission lines associated with Centaurus X-3 and identified variations suggesting that the structure responsible for the emissions was rotating along with the pulsar.
Their analysis pointed to the presence of an accretion stream, a channel of material flowing from an accretion disk toward the neutron star.
The researchers concluded that this stream was responsible for the observed changes in the secondary emission lines.
According to the ministry, identifying the accretion stream provides evidence for the existence of an accretion disk surrounding the pulsar.
The finding is particularly significant because disk-fed accretion is an important mechanism governing how neutron stars acquire matter from their companions and generate high-energy radiation.
Understanding the geometry and behavior of these structures can help scientists explain variations in X-ray emissions and refine theoretical models of binary star systems.
The discovery also provides another method for studying regions near neutron stars, where extreme gravity and powerful magnetic fields influence the movement of matter.
Researchers believe the findings could contribute to a broader understanding of high-mass X-ray binaries and the complex interactions between compact stellar objects and their surrounding environments.
The study adds to ongoing efforts to understand how some of the universe’s densest objects accumulate matter and produce intense bursts of high-energy radiation. (Source: IANS)
