A Blender in Space: Why Galactic Outflows Are Dust-Free ✛ ✦

Original: "Dust destruction signals shock-accelerated outflows in the nearby active galaxy NGC 1068"
arXiv:2606.25164 · 2026-06-23 · CC BY 4.0 · 1 min
At the heart of galaxy NGC 1068, shock waves act like the blades of a giant blender, accelerating gas and grinding cosmic dust to powder — revealing how black holes control the birth of new stars.

At the center of galaxy NGC 1068, shock waves work like the blades of a cosmic blender. They compress and accelerate gas ejected by the supermassive black hole, the active nucleus, and mercilessly grind down cosmic dust. Astronomers split the outflow's light into a rainbow using spectroscopy and saw that spectral lines of heavy elements like iron had almost vanished: the dust was destroyed into gas. This compression and dust removal proves that the outflow is driven by shock waves, not radiation pressure. In this way, the black hole regulates star formation: without dust, gas cannot clump together to form new stars. The blender is ruthless: even grains harder than diamond are pulverized into atoms, returning building material to the interstellar medium and altering the course of galactic evolution.

Some dust grains do survive: they trap calcium inside like tiny safes. These microscopic particles, coated with graphite and silicates, turn out to be tougher than earthly diamonds, yet even their armor doesn't always protect them near a black hole.

v = c \cdot \frac{\Delta\lambda}{\lambda_0}
The gas velocity v is directly related to the Doppler shift of the wavelength: the greater the shift of spectral lines, the faster the emitting material moves.
Scientists
Bernhard RiemannJoseph WeberKarl SchwarzschildKip ThorneRainer WeissAlbert Einstein
Concepts
galactic outflow acceleration galactic dust winds obscured agn ultra fast outflow galaxy growth mechanisms gas cloud active galaxy gas accretion changing agn activity cosmic dust starburst argon neutrino detection liquid argon accretion disk wind protoplanetary disk winds sulfur dioxide active galactic nucleus dust extinction dust dynamics star formation