The Effect of Galaxy Interactions on Starbursts in Milky Way-mass Galaxies in FIRE Simulations
Simulations and observations suggest that galaxy interactions may enhance the star formation rate (SFR) in merging galaxies. One proposed mechanism is the torque exerted on the gas and stars in the larger galaxy by the smaller galaxy. We analyze the interaction torques and star formation activity on...
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IOP Publishing
2025-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad94ef |
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| author | Fei Li Mubdi Rahman Norman Murray Dušan Kereš Andrew Wetzel Claude-André Faucher-Giguère Philip F. Hopkins Jorge Moreno |
| author_facet | Fei Li Mubdi Rahman Norman Murray Dušan Kereš Andrew Wetzel Claude-André Faucher-Giguère Philip F. Hopkins Jorge Moreno |
| author_sort | Fei Li |
| collection | DOAJ |
| description | Simulations and observations suggest that galaxy interactions may enhance the star formation rate (SFR) in merging galaxies. One proposed mechanism is the torque exerted on the gas and stars in the larger galaxy by the smaller galaxy. We analyze the interaction torques and star formation activity on six galaxies from the FIRE-2 simulation suite with masses comparable to the Milky Way galaxy at redshift z = 0. We trace the halos from z = 3.6 to z = 0, calculating the torque exerted by the nearby galaxies on the gas in the central galaxy. We calculate the correlation between the torque and the SFR across the simulations for various mass ratios. For near-equal-stellar-mass-ratio interactions in the galaxy sample, occurring between z = 1.2−3.6, there is a positive and statistically significant correlation between the torque from nearby galaxies on the gas of the central galaxies and the SFR. For all other samples, no statistically significant correlation is found between the torque and the SFR. Our analysis shows that some, but not all, major interactions cause starbursts in the simulated Milky Way-mass galaxies, and that most starbursts are not caused by galaxy interactions. The transition from “bursty” at high redshift ( z ≳ 1) to “steady” star formation state at later times is independent of the interaction history of the galaxies, and most of the interactions do not leave significant imprints on the overall trend of the star formation history of the galaxies. |
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| institution | Kabale University |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
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| spelling | doaj-art-e9e7d68901be43039e15372fbdbe844e2025-01-13T07:24:37ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-019791710.3847/1538-4357/ad94efThe Effect of Galaxy Interactions on Starbursts in Milky Way-mass Galaxies in FIRE SimulationsFei Li0https://orcid.org/0009-0009-0483-5762Mubdi Rahman1https://orcid.org/0000-0003-1842-6096Norman Murray2https://orcid.org/0000-0002-8659-3729Dušan Kereš3https://orcid.org/0000-0002-1666-7067Andrew Wetzel4https://orcid.org/0000-0003-0603-8942Claude-André Faucher-Giguère5https://orcid.org/0000-0002-4900-6628Philip F. Hopkins6https://orcid.org/0000-0003-3729-1684Jorge Moreno7https://orcid.org/0000-0002-3430-3232David A. Dunlap Department of Astronomy and Astrophysics, University of Toronto , 50 Saint George Street, ON M5S 3H4, Canada ; lif.li@mail.utoronto.ca; Canadian Institute for Theoretical Astrophysics, University of Toronto , 60 Saint George Street, Toronto, ON M5S 3H8, CanadaSidrat Research , 124 Merton Street, Suite 507, Toronto, ON M4S 2Z2, CanadaCanadian Institute for Theoretical Astrophysics, University of Toronto , 60 Saint George Street, Toronto, ON M5S 3H8, Canada; Canada Research Chair in Astrophysics , CanadaDepartment of Physics, Center for Astrophysics and Space Sciences, University of California at San Diego , 9500 Gilman Drive, La Jolla, CA 92093, USADepartment of Physics & Astronomy, University of California , Davis, CA 95616, USADepartment of Physics and Astronomy and CIERA, Northwestern University , 2145 Sheridan Road, Evanston, IL 60208, USATAPIR, Mailcode 350-17, California Institute of Technology , Pasadena, CA 91125, USADepartment of Physics and Astronomy, Pomona College , Claremont, CA 91711, USA; The Observatories of the Carnegie Institution for Science , 813 Santa Barbara Street, Pasadena, CA 91101, USASimulations and observations suggest that galaxy interactions may enhance the star formation rate (SFR) in merging galaxies. One proposed mechanism is the torque exerted on the gas and stars in the larger galaxy by the smaller galaxy. We analyze the interaction torques and star formation activity on six galaxies from the FIRE-2 simulation suite with masses comparable to the Milky Way galaxy at redshift z = 0. We trace the halos from z = 3.6 to z = 0, calculating the torque exerted by the nearby galaxies on the gas in the central galaxy. We calculate the correlation between the torque and the SFR across the simulations for various mass ratios. For near-equal-stellar-mass-ratio interactions in the galaxy sample, occurring between z = 1.2−3.6, there is a positive and statistically significant correlation between the torque from nearby galaxies on the gas of the central galaxies and the SFR. For all other samples, no statistically significant correlation is found between the torque and the SFR. Our analysis shows that some, but not all, major interactions cause starbursts in the simulated Milky Way-mass galaxies, and that most starbursts are not caused by galaxy interactions. The transition from “bursty” at high redshift ( z ≳ 1) to “steady” star formation state at later times is independent of the interaction history of the galaxies, and most of the interactions do not leave significant imprints on the overall trend of the star formation history of the galaxies.https://doi.org/10.3847/1538-4357/ad94efGalaxy evolutionGalaxy interactions |
| spellingShingle | Fei Li Mubdi Rahman Norman Murray Dušan Kereš Andrew Wetzel Claude-André Faucher-Giguère Philip F. Hopkins Jorge Moreno The Effect of Galaxy Interactions on Starbursts in Milky Way-mass Galaxies in FIRE Simulations The Astrophysical Journal Galaxy evolution Galaxy interactions |
| title | The Effect of Galaxy Interactions on Starbursts in Milky Way-mass Galaxies in FIRE Simulations |
| title_full | The Effect of Galaxy Interactions on Starbursts in Milky Way-mass Galaxies in FIRE Simulations |
| title_fullStr | The Effect of Galaxy Interactions on Starbursts in Milky Way-mass Galaxies in FIRE Simulations |
| title_full_unstemmed | The Effect of Galaxy Interactions on Starbursts in Milky Way-mass Galaxies in FIRE Simulations |
| title_short | The Effect of Galaxy Interactions on Starbursts in Milky Way-mass Galaxies in FIRE Simulations |
| title_sort | effect of galaxy interactions on starbursts in milky way mass galaxies in fire simulations |
| topic | Galaxy evolution Galaxy interactions |
| url | https://doi.org/10.3847/1538-4357/ad94ef |
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