SF-R You Sure? The Conflicting Role of Star Formation Rates in Constraining the Evolution of Milky Way Analogs in Cosmological Simulations
Milky Way analogs (MWAs) have long been studied by astronomers to place our Galaxy within an extragalactic context. With the power of cosmological simulations, we are now able to not only characterize MWAs today, but also watch as they evolve through cosmic time. We use the Evolution and Assembly of...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/adc38c |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850187176338259968 |
|---|---|
| author | Alicia M. Savelli Joshua S. Speagle J. Ted Mackereth Norman Murray Kartheik G. Iyer |
| author_facet | Alicia M. Savelli Joshua S. Speagle J. Ted Mackereth Norman Murray Kartheik G. Iyer |
| author_sort | Alicia M. Savelli |
| collection | DOAJ |
| description | Milky Way analogs (MWAs) have long been studied by astronomers to place our Galaxy within an extragalactic context. With the power of cosmological simulations, we are now able to not only characterize MWAs today, but also watch as they evolve through cosmic time. We use the Evolution and Assembly of GaLaxies and their Environments (EAGLE) and Illustris The Next Generation (IllustrisTNG) simulations to study a group of MWAs defined by their stellar mass (SM) and star formation rate (SFR). We trace these galaxies back along their evolution to investigate the star-forming and mass assembly tracks taken by a galaxy to become an MWA today in light of these chosen parameters. We also take mock-observations of “MWAs” at z > 0 and trace them forward in time to determine if galaxies that looked similar to the Milky Way earlier in their evolution still look like the Milky Way today, thus quantifying a selection efficiency that could inform future observational studies of MWAs. We find that most galaxies with Milky Way–SM follow a similar evolution regardless of present-day SFR, although MWAs in IllustrisTNG generally have not quenched, leading to star formation histories that produce “too-blue” galaxies today. Additionally, we find contamination by MWA-“imposters” in our mock-observations, with low selection efficiency at high redshift due to the tight constraint requiring convergence to the Milky Way’s present-day SFR. Our work suggests present-day SM may suffice as a stand-alone selection parameter and helps to clarify how MWAs should be selected, and thus will be an important reference for future studies of both simulated and observed MWAs. |
| format | Article |
| id | doaj-art-3a4e44d7c6b94a7c97c87c629bcaaff5 |
| institution | OA Journals |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-3a4e44d7c6b94a7c97c87c629bcaaff52025-08-20T02:16:10ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01984219510.3847/1538-4357/adc38cSF-R You Sure? The Conflicting Role of Star Formation Rates in Constraining the Evolution of Milky Way Analogs in Cosmological SimulationsAlicia M. Savelli0https://orcid.org/0000-0003-0147-9562Joshua S. Speagle1https://orcid.org/0000-0003-2573-9832J. Ted Mackereth2https://orcid.org/0000-0001-8108-0935Norman Murray3https://orcid.org/0000-0002-8659-3729Kartheik G. Iyer4https://orcid.org/0000-0001-9298-3523Canadian Institute for Theoretical Astrophysics, University of Toronto , 60 St. George Street, Toronto, ON M5S 3H8, Canada ; alicia.savelli@utoronto.ca; David A. Dunlap Department of Astronomy & Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, Canada; Dunlap Institute for Astronomy & Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, Canada; Department of Physics, Brock University , 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, CanadaDavid A. Dunlap Department of Astronomy & Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, Canada; Dunlap Institute for Astronomy & Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, Canada; Department of Statistical Sciences, University of Toronto , 9th Floor, Ontario Power Building, 700 University Avenue, Toronto, ON M5G 1Z5, Canada; Data Sciences Institute, University of Toronto , 17th Floor, Ontario Power Building, 700 University Avenue, Toronto, ON M5G 1Z5, CanadaCanadian Institute for Theoretical Astrophysics, University of Toronto , 60 St. George Street, Toronto, ON M5S 3H8, Canada ; alicia.savelli@utoronto.ca; David A. Dunlap Department of Astronomy & Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, Canada; Dunlap Institute for Astronomy & Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, CanadaCanadian Institute for Theoretical Astrophysics, University of Toronto , 60 St. George Street, Toronto, ON M5S 3H8, Canada ; alicia.savelli@utoronto.ca; David A. Dunlap Department of Astronomy & Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, Canada; Department of Physics, University of Toronto , 60 St. George Street, Toronto, ON M5S 1A7, CanadaDunlap Institute for Astronomy & Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, Canada; Columbia Astrophysics Laboratory, Columbia University , 550 West 120th Street, New York, NY 10027, USAMilky Way analogs (MWAs) have long been studied by astronomers to place our Galaxy within an extragalactic context. With the power of cosmological simulations, we are now able to not only characterize MWAs today, but also watch as they evolve through cosmic time. We use the Evolution and Assembly of GaLaxies and their Environments (EAGLE) and Illustris The Next Generation (IllustrisTNG) simulations to study a group of MWAs defined by their stellar mass (SM) and star formation rate (SFR). We trace these galaxies back along their evolution to investigate the star-forming and mass assembly tracks taken by a galaxy to become an MWA today in light of these chosen parameters. We also take mock-observations of “MWAs” at z > 0 and trace them forward in time to determine if galaxies that looked similar to the Milky Way earlier in their evolution still look like the Milky Way today, thus quantifying a selection efficiency that could inform future observational studies of MWAs. We find that most galaxies with Milky Way–SM follow a similar evolution regardless of present-day SFR, although MWAs in IllustrisTNG generally have not quenched, leading to star formation histories that produce “too-blue” galaxies today. Additionally, we find contamination by MWA-“imposters” in our mock-observations, with low selection efficiency at high redshift due to the tight constraint requiring convergence to the Milky Way’s present-day SFR. Our work suggests present-day SM may suffice as a stand-alone selection parameter and helps to clarify how MWAs should be selected, and thus will be an important reference for future studies of both simulated and observed MWAs.https://doi.org/10.3847/1538-4357/adc38cthe Milky WayMilky Way evolutionGalaxy evolutionHydrodynamical simulationsthe Milky Way physicsTheoretical techniques |
| spellingShingle | Alicia M. Savelli Joshua S. Speagle J. Ted Mackereth Norman Murray Kartheik G. Iyer SF-R You Sure? The Conflicting Role of Star Formation Rates in Constraining the Evolution of Milky Way Analogs in Cosmological Simulations The Astrophysical Journal the Milky Way Milky Way evolution Galaxy evolution Hydrodynamical simulations the Milky Way physics Theoretical techniques |
| title | SF-R You Sure? The Conflicting Role of Star Formation Rates in Constraining the Evolution of Milky Way Analogs in Cosmological Simulations |
| title_full | SF-R You Sure? The Conflicting Role of Star Formation Rates in Constraining the Evolution of Milky Way Analogs in Cosmological Simulations |
| title_fullStr | SF-R You Sure? The Conflicting Role of Star Formation Rates in Constraining the Evolution of Milky Way Analogs in Cosmological Simulations |
| title_full_unstemmed | SF-R You Sure? The Conflicting Role of Star Formation Rates in Constraining the Evolution of Milky Way Analogs in Cosmological Simulations |
| title_short | SF-R You Sure? The Conflicting Role of Star Formation Rates in Constraining the Evolution of Milky Way Analogs in Cosmological Simulations |
| title_sort | sf r you sure the conflicting role of star formation rates in constraining the evolution of milky way analogs in cosmological simulations |
| topic | the Milky Way Milky Way evolution Galaxy evolution Hydrodynamical simulations the Milky Way physics Theoretical techniques |
| url | https://doi.org/10.3847/1538-4357/adc38c |
| work_keys_str_mv | AT aliciamsavelli sfryousuretheconflictingroleofstarformationratesinconstrainingtheevolutionofmilkywayanalogsincosmologicalsimulations AT joshuasspeagle sfryousuretheconflictingroleofstarformationratesinconstrainingtheevolutionofmilkywayanalogsincosmologicalsimulations AT jtedmackereth sfryousuretheconflictingroleofstarformationratesinconstrainingtheevolutionofmilkywayanalogsincosmologicalsimulations AT normanmurray sfryousuretheconflictingroleofstarformationratesinconstrainingtheevolutionofmilkywayanalogsincosmologicalsimulations AT kartheikgiyer sfryousuretheconflictingroleofstarformationratesinconstrainingtheevolutionofmilkywayanalogsincosmologicalsimulations |