Séminaire/Seminar Galaxies |
| « Ram-pressure-induced star formation in infalling Coma cluster dwarfs: the role of galaxy orbits » |
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Kirill Grishin |
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As small galaxies fall into massive galaxy clusters, they push through the hot gas in the cluster. This "ram pressure" strips gas away and eventually shuts down star formation. But before the gas is gone, the same pressure can squeeze it and spark one last burst of star formation. It's still unclear how often this happens or what decides whether a galaxy gets this final burst.
Using data from the DESI survey, we found 39 dwarf galaxies in the Coma cluster that show signs of a recent burst followed by shutdown -- post-starburst galaxies (PSGs). We compared their orbits to galaxies with current star formation (SFGs), estimating how circular or radial each orbit likely is. PSGs mostly have circular orbits, while SFGs often have more radial ones. This suggests a ram-pressure--induced starburst happens when stripping is gradual, giving the galaxy time to turn its remaining gas into stars before losing it -- rather than being stripped too fast. |
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jeudi 10 septembre 2026 - 11:30 Salle Entresol Daniel Chalonge Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |