NASA Telescope Study of Blazars Uncovers New X-Ray Clues About Black Hole Energy

Key facts

• Astronomers from the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, studied four TeV blazars — Mrk 421, Mrk 501, PG 1553+113 and PKS 2155-304 — using NASA's NICER and NuSTAR telescopes, analysing 13 sets of X-ray observations.
• The study found that X-ray emissions from blazars may not come only from black hole jets; during low to moderate activity states, radiation from the accretion flow around the black hole may also contribute.
• Mrk 421 and Mrk 501 showed an additional low-energy X-ray component, with Mrk 501 showing such evidence for the first time, while PG 1553+113 and PKS 2155-304 were explained well by existing models.
• The research, published in The Astrophysical Journal, was carried out by researchers Riya Bhowmik and Alok C. Gupta, and further observations are needed to confirm the accretion-related X-ray contribution.