%0 Generic %1 voit2015supernova %A Voit, G. M. %A Donahue, M. %A O'Shea, B. W. %A Bryan, G. L. %A Sun, M. %A Werner, N. %D 2015 %K black early feedback hole supernova type %T Supernova Sweeping and Black-Hole Feedback in Elliptical Galaxies %U http://arxiv.org/abs/1503.02104 %X Most of the massive elliptical galaxies in the universe stopped forming stars billions of years ago, even though plenty of hot gas remains available for star formation. Here we present compelling evidence indicating that quenching of star formation depends on both black-hole feedback and Type Ia supernova heating. We analyze Chandra X-ray observations of ten massive ellipticals, five with extended, potentially star-forming multiphase gas and five single-phase ellipticals with no star formation. The ratio of cooling time to freefall time at 1--10 kpc in the multiphase galaxies is tc/tff ~10, indicating that precipitation-driven feedback limits cooling but does not eliminate condensation. In the same region of the single-phase galaxies, the radial profiles of gas entropy are consistent with a thermally stable (tc/tff > 20) supernova-driven outflow that sweeps stellar ejecta out of the galaxy. However, in one of those single-phase ellipticals (NGC 4261) we find tc/tff < 10 at < 300 pc. Notably, its jets are ~50 times more powerful than in the other nine ellipticals, in agreement with models indicating that precipitation near the black hole should switch its fueling mode from Bondi-like accretion to cold chaotic accretion. We conclude by hypothesizing that black-hole feedback outbursts shut off star formation in massive elliptical galaxies by switching on supernova sweeping capable of raising the entropy of the outflowing stellar ejecta to > 100 keV cm^2.

@misc{voit2015supernova, abstract = {Most of the massive elliptical galaxies in the universe stopped forming stars billions of years ago, even though plenty of hot gas remains available for star formation. Here we present compelling evidence indicating that quenching of star formation depends on both black-hole feedback and Type Ia supernova heating. We analyze Chandra X-ray observations of ten massive ellipticals, five with extended, potentially star-forming multiphase gas and five single-phase ellipticals with no star formation. The ratio of cooling time to freefall time at 1--10 kpc in the multiphase galaxies is tc/tff ~10, indicating that precipitation-driven feedback limits cooling but does not eliminate condensation. In the same region of the single-phase galaxies, the radial profiles of gas entropy are consistent with a thermally stable (tc/tff > 20) supernova-driven outflow that sweeps stellar ejecta out of the galaxy. However, in one of those single-phase ellipticals (NGC 4261) we find tc/tff < 10 at < 300 pc. Notably, its jets are ~50 times more powerful than in the other nine ellipticals, in agreement with models indicating that precipitation near the black hole should switch its fueling mode from Bondi-like accretion to cold chaotic accretion. We conclude by hypothesizing that black-hole feedback outbursts shut off star formation in massive elliptical galaxies by switching on supernova sweeping capable of raising the entropy of the outflowing stellar ejecta to > 100 keV cm^2.}, added-at = {2015-03-10T09:49:56.000+0100}, author = {Voit, G. M. and Donahue, M. and O'Shea, B. W. and Bryan, G. L. and Sun, M. and Werner, N.}, biburl = {https://www.bibsonomy.org/bibtex/251be9d0527c24f3501aa9ca345756ac7/miki}, description = {[1503.02104] Supernova Sweeping and Black-Hole Feedback in Elliptical Galaxies}, interhash = {298d6e5bef89d626f4ebcc481273fe8a}, intrahash = {51be9d0527c24f3501aa9ca345756ac7}, keywords = {black early feedback hole supernova type}, note = {cite arxiv:1503.02104Comment: Submitted to ApJ Letters, 5 pages, 2 figures}, timestamp = {2015-03-10T09:49:56.000+0100}, title = {Supernova Sweeping and Black-Hole Feedback in Elliptical Galaxies}, url = {http://arxiv.org/abs/1503.02104}, year = 2015 }