Pulsing Signals Reveal Hidden Structure Around a Famous Neutron Star

Key Highlights:

• Scientists discovered that the X-ray pulsar Centaurus X-3 accretes material through an accretion disk, which is rare for high-mass X-ray binaries (HMXBs).
• This finding challenges existing models for HMXBs, which typically accrete via direct stellar wind capture.
• The research was conducted by scientists from the Raman Research Institute (RRI), an autonomous institution under the Department of Science and Technology (DST).
• The study investigated secondary emission lines to deduce the presence of an accretion disk and accretion stream.

Detailed Insights:

• Centaurus X-3 is one of the brightest X-ray pulsars and was among the first discovered, located 24,000 light-years away.
• It is a high-mass X-ray binary (HMXB), meaning its companion star is more than 10 times the Sun's mass.
• The variability in secondary emission lines, caused by an accretion stream, indicated the presence of an accretion disk.
• This discovery will lead to better-informed models of such systems and enhance the understanding of binary pulsars generally.
• Studying secondary radiation from structures around a pulsar helps determine physical parameters like orientation and magnetic field strength.

Scientific/Technical Concepts Involved:

• X-ray Pulsar: A highly magnetized, rotating neutron star that emits X-rays as it accretes material from a companion star.
• Neutron Star: A superdense remnant of a massive star, with its mass compressed into a sphere roughly the size of a city.
• Accretion Disk: A rotating disk of gas and dust that spirals inward onto a massive object, such as a neutron star, due to gravity.
• High-Mass X-ray Binary (HMXB): A binary star system where a compact object, like a neutron star, accretes material from a massive companion star.