Four parameters suffice to describe dust attenuation curve diversity in TNG simulations, yielding a new symbolic-regression model that recovers curves and fluxes better than existing parameterizations while linking parameters to SFR surface density, metallicity, and geometry.
The star-formation activity of IllustrisTNG galaxies: main sequence, UVJ diagram, quenched fractions, and systematics
7 Pith papers cite this work. Polarity classification is still indexing.
abstract
We select galaxies from the IllustrisTNG hydrodynamical simulations ($M_*>10^9~\rm M_\odot$ at $0\le z\le2$) and characterize the shapes and evolutions of their UVJ and star-formation rate -- stellar mass (SFR-$M_*$) diagrams. We quantify the systematic uncertainties related to different criteria to classify star-forming vs. quiescent galaxies, different SFR estimates, and by accounting for the star formation measured within different physical apertures. The TNG model returns the observed features of the UVJ diagram at $z\leq2$, with a clear separation between two classes of galaxies. It also returns a tight star-forming main sequence (MS) for $M_*<10^{10.5}\,\rm M_\odot$ with a $\sim0.3$ dex scatter at $z\sim0$ in our fiducial choices. If a UVJ-based cut is adopted, the TNG MS exhibits a downwardly bending at stellar masses of about $10^{10.5-10.7}~\rm M_\odot$. Moreover, the model predicts that $\sim80\,(50)$ per cent of $10^{10.5-11}~\rm M_\odot$ galaxies at $z=0~(z=2)$ are quiescent and the numbers of quenched galaxies at intermediate redshifts and high masses are in better agreement with observational estimates than previous models. However, shorter SFR-averaging timescales imply higher normalizations and scatter of the MS, while smaller apertures lead to underestimating the galaxy SFRs: overall we estimate the inspected systematic uncertainties to sum up to about $0.2-0.3$ dex in the locus of the MS and to about 15 percentage points in the quenched fractions. While TNG color distributions are clearly bimodal, this is not the case for the SFR logarithmic distributions in bins of stellar mass (SFR$\geq 10^{-3}~\rm M_\odot$yr$^{-1}$). Finally, the slope and $z=0$ normalization of the TNG MS are consistent with observational findings; however, the locus of the TNG MS remains lower by about $0.2-0.5$ dex at $0.75\le z<2$ than the available observational estimates taken at face value.
representative citing papers
UVJ colors saturate below log(sSFR) ~ -10.5; new UV/MIR color-color diagrams allow more efficient selection of galaxies with substantially lower ongoing star formation.
In 37 massive ETGs, the IMF becomes less bottom-heavy with radius, with average α_IMF falling from 2.16 to 1.74 and IMF gradients dominating M/L variations over stellar population effects.
KMeans clustering of star-formation histories for 6051 LAEs in IllustrisTNG100 at z=2 yields four classes, with 35% showing the typical recent-burst profile and 65% having bursts 0.3-1.3 Gyr earlier.
Low-mass filament galaxies in TNG50 exhibit smaller asymmetric cold gas discs due to cosmic web tidal fields causing altered accretion or starvation and late-time stripping, while integrated stellar and halo properties remain similar to field counterparts after mass and environment controls.
LEGGOS presents a uniform framework that jointly models lensing, photometry, and integral-field spectroscopy to disentangle stellar populations in clumps of high-redshift lensed galaxies.