Overview
- Researchers report in Nature Astronomy on Friday that JCMT0402−0424, nicknamed 'Shadow Blaster,' is the leading provisional electromagnetic counterpart to the 2021 IceCube event IC 210922A.
- ALMA, JCMT, the Submillimeter Array and Gemini resolved the source after a foreground galaxy gravitationally lensed and amplified its submillimeter and radio emission, allowing detailed study at z ≈ 2.99.
- The team’s lens modeling and spectra reveal a dense, compact central region roughly 1,500 light‑years across that is rich in gas and dust and shows no clear signs of an active supermassive black hole.
- Authors say those extreme, star‑formation driven conditions can act as cosmic‑ray calorimeters that produce high‑energy neutrinos and estimate similar galaxies could supply up to about 20% of IceCube’s diffuse neutrino background, but they call the association provisional and dependent on independent lensing and neutrino‑production tests.
- If confirmed, the finding would broaden the search for neutrino sources beyond active galactic nuclei to heavily obscured starburst galaxies and it will push observers to target lensed, dust‑enshrouded systems in future multimessenger follow‑up.