The time-scales probed by star formation rate indicators for realistic, bursty star formation histories from the FIRE simulations

Velázquez, José A. Flores; Gurvich, Alexander B.; Faucher-Giguère, Claude André; Bullock, James S.; Starkenburg, Tjitske K.; Moreno, Jorge; Lazar, Alexandres; Mercado, Francisco J.; Stern, Jonathan; Sparre, Martin; Hayward, Christopher C.; Wetzel, Andrew; El-Badry, Kareem

doi:10.1093/mnras/staa3893

Cited by 86 publications

(53 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We see that the relative variance is much larger at early times than at late times, consistent with previous studies (e.g. Stern et al 2020;Flores Velázquez et al 2021) that have shown that star formation in massive FIRE-2 galaxies tends to transition from bursty to steady as we approach the present day.…”

Section: Bursty Phase Steady Phase and Age Distributionssupporting

confidence: 92%

The bursty origin of the Milky Way thick disc

Bullock

Klein

et al. 2021

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

We investigate thin and thick stellar disc formation in Milky-Way-mass galaxies using twelve FIRE-2 cosmological zoom-in simulations. All simulated galaxies experience an early period of bursty star formation that transitions to a late-time steady phase of near-constant star formation. Stars formed during the late-time steady phase have more circular orbits and thin-disc-like morphology at z = 0, whilst stars born during the bursty phase have more radial orbits and thick-disc structure. The median age of thick-disc stars at z = 0 correlates strongly with this transition time. We also find that galaxies with an earlier transition from bursty to steady star formation have a higher thin-disc fractions at z = 0. Three of our systems have minor mergers with LMC-size satellites during the thin-disc phase. These mergers trigger short starbursts but do not destroy the thin disc nor alter broad trends between the star formation transition time and thin/thick disc properties. If our simulations are representative of the Universe, then stellar archaeological studies of the Milky Way (or M31) provide a window into past star-formation modes in the Galaxy. Current age estimates of the Galactic thick disc would suggest that the Milky Way transitioned from bursty to steady phase ∼6.5 Gyr ago; prior to that time the Milky Way likely lacked a recognisable thin disc.

show abstract

Section: Bursty Phase Steady Phase and Age Distributionssupporting

confidence: 92%

The bursty origin of the Milky Way thick disc

Bullock

Klein

et al. 2021

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Bursty Phase Steady Phase and Age Distributionssupporting

confidence: 91%

The bursty origin of the Milky Way thick disc

Yu,

Bullock,

Klein

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

We investigate thin and thick stellar disc formation in Milky-Way-mass galaxies using twelve FIRE-2 cosmological zoom-in simulations. All simulated galaxies experience an early period of bursty star formation that transitions to a late-time steady phase of near-constant star formation. Stars formed during the late-time steady phase have more circular orbits and thindisc-like morphology at 𝑧 = 0, whilst stars born during the bursty phase have more radial orbits and thick-disc structure. The median age of thick-disc stars at 𝑧 = 0 correlates strongly with this transition time. We also find that galaxies with an earlier transition from bursty to steady star formation have a higher thin-disc fractions at 𝑧 = 0. Three of our systems have minor mergers with LMC-size satellites during the thin-disc phase. These mergers trigger short starbursts but do not destroy the thin disc nor alter broad trends between the star formation transition time and thin/thick disc properties. If our simulations are representative of the Universe, then stellar archaeological studies of the Milky Way (or M31) provide a window into past star-formation modes in the Galaxy. Current age estimates of the Galactic thick disc would suggest that the Milky Way transitioned from bursty to steady phase ∼6.5 Gyr ago; prior to that time the Milky Way likely lacked a recognisable thin disc.

show abstract

“…We note that in the FIRE simulations, the resolved ISM produces star formation histories that are generically bursty for dwarf galaxies (e.g. Sparre et al 2017;Faucher-Giguère 2018;Flores Velázquez et al 2021), an effect which can be suppressed in lower-resolution simulations that use simplified ISM prescriptions. The mass of the individual star particles is sufficiently small to support the assumption that each represents a single-age, single-metallicity stellar population while still being large enough to fully sample the IMF at the high-mass end (Sanderson et al 2020).…”

Section: The Fire Simulationsmentioning

confidence: 94%

The In-situ Origins of Dwarf Stellar Outskirts in FIRE-2

Kado-Fong,

Sanderson,

Greene

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Extended, old, and round stellar halos appear to be ubiquitous around high-mass dwarf galaxies (10 8.5 < M /M < 10 9.6 ) in the observed universe. However, it is unlikely that these dwarfs have undergone a sufficient number of minor mergers to form stellar halos that are composed of predominantly accreted stars. Here, we demonstrate that FIRE-2 (Feedback in Realistic Environments) cosmological zoom-in simulations are capable of producing dwarf galaxies with realistic structure, including both a thick disk and round stellar halo. Crucially, these stellar halos are formed in-situ, largely via the outward migration of disk stars. However, there also exists a large population of "non-disky" dwarfs in FIRE that lack a well-defined disk/halo and do not resemble the observed dwarf population. These non-disky dwarfs tend to be either more gas poor or to have burstier recent star formation histories than the disky dwarfs, suggesting that star formation feedback may be preventing disk formation. Both classes of dwarfs underscore the power of a galaxy's intrinsic shape -which is a direct quantification of the distribution of the galaxy's stellar content -to interrogate the feedback implementation in simulated galaxies.

show abstract

The time-scales probed by star formation rate indicators for realistic, bursty star formation histories from the FIRE simulations

Cited by 86 publications

References 82 publications

The bursty origin of the Milky Way thick disc

The bursty origin of the Milky Way thick disc

The bursty origin of the Milky Way thick disc

The In-situ Origins of Dwarf Stellar Outskirts in FIRE-2

Contact Info

Product

Resources

About