![stellar ram pressure stellar ram pressure](https://image1.slideserve.com/3217314/slide13-l.jpg)
Figure 7 in the paper.įigure 1 shows the fraction of quiescent galaxies by the environment of their last site of star formation (effectively showing the location where the galaxy quenched). Blue dashed line corresponds to galaxies that are quenched in the Milky Way halo, grey dotted line corresponds to galaxies that quench in isolation as centrals, and the yellow line corresponds to galaxies that quench as a part of a low-mass group prior to orbiting the Milky Way. Figure 1: Location of galaxy quenching as a function of galaxy stellar mass. While environmental processes such as ram-pressure stripping are thought to play a large role in the shut-down of star formation in satellite galaxies, Figure 1 shows that environmental processes occurring in MW-mass halos are not solely to blame. Today’s authors investigate the effect of environment on the gas content and star-formation rates of present day satellite galaxies in the FIRE-2 simulations, ultimately aiming to answer the question: where and when does star formation shut-off in satellite galaxies of MW-mass hosts? Where?
![stellar ram pressure stellar ram pressure](https://www.welectronics.com/images/stories/virtuemart/product/black1527.jpg)
It is possible that these galaxies are “preprocessed” by the smaller group, and so start to quench within this small group even before they cross the boundary of the Milky Way halo. For example, some satellites of the Milky Way are expected to have joined a smaller group of galaxies before entering the Milky Way environment. While environmental effects such as ram-pressure stripping can explain the difference in star-formation rates observed between satellite galaxies and isolated galaxies, the exact role that environment plays in quenching a galaxy, and how this varies with galaxy mass, remains unclear. If this force due to ram-pressure is larger than the gravitational force binding the gas to the satellite galaxy, the gas that is necessary for star formation can be stripped and removed from the satellite galaxy. As satellite galaxies move through the gaseous medium of their host halo, the relative bulk motion causes them to experience a drag force. One explanation for this difference is ram-pressure stripping. Satellite galaxies (galaxies that are orbiting a larger host galaxy) are particularly sensitive to quenching processes, and observations of satellite galaxies of the Milky Way (MW) show that satellites contain less star-forming gas and have lower star formation rates relative to similar mass galaxies that exist in isolation. Galaxies that are no longer actively forming stars are typically referred to as “quiescent”‘ or “quenched’ (see this astrobite for more), and observations reveal that the environment that a galaxy inhabits can have a dramatic effect on whether or not it will continue to form stars. Many physical processes are thought to be responsible for shutting down star formation in galaxies. Title: Extinguishing the FIRE: environmental quenching of satellite galaxies around Milky Way-mass hosts in simulationsĪuthors: Jenna Samuel, Andrew Wetzel, Isaiah Santistevan, Erik Tollerud, Jorge Moreno, Michael Boylan-Kolchin, Jeremy Bailin, Bhavya Pardasaniįirst Author’s Institution: Department of Astronomy, The University of Texas at Austin