Bar-driven gas redistribution suppresses star formation in spiral galaxy NGC 3351
Researchers using HST, ALMA, and AstroSat/UVIT imaging have found that the stellar bar in spiral galaxy NGC 3351 channels molecular gas toward the galactic nucleus, leaving dust lanes along the bar devoid of gas and recent star formation. The study interprets the inward orientation of dust lane morphology as a fossil record of past gas inflows driven by the bar's gravitational influence. The findings help clarify how galactic bars can simultaneously build central gas reservoirs while quenching star formation in the bar region itself.
A new observational study accepted for publication in Astronomy & Astrophysics Letters presents multi-wavelength evidence that the stellar bar of the face-on spiral galaxy NGC 3351 has redistributed molecular gas from the bar region into the galaxy's nucleus. Using high-resolution data from the Hubble Space Telescope (HST), ALMA, and AstroSat/UVIT, the team identified dust lanes in an HST color map (F438W–F814W) that are conspicuously absent of molecular gas and show no signatures of recent star formation. The inward-pointing morphology of these dust lanes is interpreted as a directional indicator of historical gas inflows along the bar toward the center. This supports a scenario in which the bar has efficiently funneled gas into a central reservoir over time, depleting the bar region and suppressing star formation there. The results add observational weight to theoretical models of bar-driven secular evolution in disk galaxies, demonstrating that dust lane geometry can serve as a tracer of past gas dynamics even after the gas itself has been transported away.
What's missing
The study does not quantify the timescale over which the bar has been active or how long ago the gas redistribution occurred, leaving open questions about the evolutionary stage of NGC 3351's bar. It also does not compare NGC 3351 to a statistical sample of barred galaxies to assess how representative this mechanism is. The causal link between dust lane morphology and past gas inflow is inferred rather than directly observed, which is an inherent limitation of the single-epoch observational approach.
What different sources said
- arXiv astro-phCenter
Bar-driven gas redistribution suppresses star formation in spiral galaxies: Evidence from dust lanes in NGC 3351
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