Indian astronomers trace the origin of mysterious cosmic X-ray flashes

Researchers at the DST's Indian Institute of Astrophysics found a radio counterpart to a Fast X-ray Transient, linking these enigmatic, brief X-ray bursts to a collapsing massive star or a neutron-star merger.

What happened

• Astronomers traced the mechanism behind a Fast X-ray Transient (FXT) — a mysterious, non-repeating flash of X-rays — detected on 7 November 2024.
• They linked it to the collapse of a massive star or the merger of two neutron stars, helping explain the physics of these extreme events.
• FXTs are energetic, non-repeating bursts of low-energy X-rays lasting minutes to hours before fading; their brevity has long kept their origins uncertain.
• The study, led by researchers at the Indian Institute of Astrophysics (an autonomous DST institution), focused on event EP241107a, detected by the Einstein Probe (a Chinese high-energy-sky survey mission).
• Using a multi-wavelength approach, the team found a radio counterpart with the Karl G. Jansky Very Large Array (USA), alongside ground-based telescopes.

For Prelims

• Fast X-ray Transients (FXTs): Brief, non-repeating bursts of X-rays (minutes to hours) from violent cosmic events; a relatively new class of transients discovered about a decade ago.
• Likely origins: Proposed progenitors include supernova shock breakouts (collapse of a massive star) and binary neutron-star mergers — both extreme, energetic phenomena.
• Indian Institute of Astrophysics (IIA): A Bengaluru-based autonomous institute under the DST, working on astronomy and astrophysics (it operates observatories like Kavalur and Hanle).
• Einstein Probe: A Chinese space mission that surveys the dynamic high-energy (X-ray) sky and detects short-lived transient events like FXTs.
• Multi-wavelength astronomy: Combining observations across X-ray, radio, optical etc. to identify counterparts and pinpoint the nature of a cosmic source.
• Very Large Array (VLA): The Karl G. Jansky Very Large Array (New Mexico, USA) is a powerful radio telescope used here to find the flash's radio counterpart.
• Don't confuse: FXTs (X-ray flashes) are distinct from Fast Radio Bursts (radio) and from classic gamma-ray bursts, though they can be related to low-luminosity GRBs.

For Mains

Syllabus: GS3.13 · GS3.10 · Linkage L2