ARIES-led study links plasma composition to the different shapes of black-hole jets
On 6 May 2026 DST said a study led by scientists of ARIES, Nainital, published in The Astrophysical Journal, used 3D simulations to show that the plasma composition of extragalactic jets and their environment can explain why some appear core-brightened (FR I) and others edge-brightened (FR II).
Summary
A study by Priyesh Kumar Tripathi, Dr Indranil Chattopadhyay and Sanjit Debnath of the Aryabhatta Research Institute of Observational Sciences (ARIES), with researchers from Poland, Presidency University Kolkata and MJPRU Bareilly, published in The Astrophysical Journal, used large 3D magnetohydrodynamic simulations to explain why extragalactic jets from supermassive black holes look different, the Ministry of Science and Technology said on 6 May 2026. Since Fanaroff and Riley's 1974 classification, jets have been grouped as core-brightened FR I and edge-brightened FR II. The team found that a 'kink instability' shapes the jets and that plasma composition matters: positron-rich (lepton-rich) jets are hotter, expand and slow down, get twisted and form diffuse FR I-like structures.
Key facts
- Study
- ARIES-led; published in The Astrophysical Journal
- Method
- 3D magnetohydrodynamic simulations at kiloparsec scales
- Classes
- FR I core-brightened; FR II edge-brightened (Fanaroff & Riley, 1974)
- Finding
- Jet plasma composition and environment shape appearance; kink instability key
- Lepton-rich jets
- Hotter, expand, slow down, form diffuse FR I-like structures
Practice MCQs 2 questions
In the Fanaroff–Riley classification of extragalactic radio jets, FR II jets are described as:
Show answer
Correct answer: B — Edge-brightened, staying focused and forming hot spots at their tips
FR II jets are edge-brightened: fainter near the core but tightly focused over long distances, forming hot spots at their tips; FR I jets are core-brightened.
According to the ARIES-led study of May 2026, what happens to positron-rich (lepton-rich) extragalactic jets?
Show answer
Correct answer: B — They become hotter, expand, slow down and form diffuse FR I-like structures
The simulations showed lepton-rich jets are hotter, expand and slow down, get twisted by the kink instability and form diffuse FR I-like structures.