The James Webb telescope found 'monster' black holes in tiny galaxies that are 60 times bigger than expected.
March 19, 2026
Original Paper
JWST Reveals Two Overmassive Black Hole Candidates in Dwarf Galaxies at z $\approx$ 0.7: Pushing Black Hole Searches into the Dwarf-Galaxy Regime
arXiv · 2603.17967
The Takeaway
In standard astronomy, a central black hole is usually only 0.1% of its galaxy's mass, but these black holes account for over half the weight of their entire host systems. This discovery suggests that some black holes don't grow slowly alongside their galaxies, but instead start out as massive giants.
From the abstract
We report the discovery and characterization of two compact galaxies, Pelias and Neleus, at z ~ 0.71 and z ~ 0.75, identified in MACS J0416.1-2403 and GOODS-North. Both exhibit unusual spectral energy distributions (SEDs), with very blue rest-frame UV-optical emission and a steep rise toward near- and mid-infrared wavelengths. JWST/NIRISS and JWST/NIRSpec spectroscopy show strong rest-frame optical lines ([O III] 4959,5007 and Halpha) with extreme equivalent widths (>= 1000 Angstrom), indicating