Cosmic web imprints on galaxy spin and star formation in the nearby Universe

by Dr Stefania Barsanti (Australian National University)

Wednesday 4 Jun 2025, 11:30 → 12:30 Europe/Rome

Sala Jappelli (Osservatorio astronomico di Padova)

In this talk, I'll present how large-scale structures impact galaxy angular momentum and the spatial distribution of star formation, based on data from the SAMI Galaxy Survey, the GAMA spectroscopic redshift survey, and eROSITA. We find that the orientation of galaxy spin with respect to the closest filament depends on bulge mass, with low-bulge mass galaxies aligning parallel to filaments and high-bulge mass ones aligning perpendicularly, suggesting a transition from gas accretion to merger-driven growth. Separate analyses of bulge, disc, and gas kinematics reveal distinct alignment trends, with AGN activity influencing ionised gas spin–filament alignments. The cosmic web leaves an imprint also on the amplitude of galaxy angular momentum, with a strong correlation between stellar spin and filament distance: pre-processing by mergers occurring within filaments is found an important physical mechanism for slowing down stellar spin before galaxies reach nodes. Extending the role of the cosmic web to star formation quenching, galaxies in X-ray+optical groups- located in nodes- show the most centrally concentrated star formation compared to only-optical groups and field galaxies, suggesting that gas-related environmental processes driving outside-in quenching are most active in node environments.

 

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https://unipd.zoom.us/j/85273198731?pwd=V1ZiNE9ZWUN4ZTdIUzJsTFo0Z3U2Zz09
Meeting ID: 852 7319 8731
Passcode: 208186