Quantifying the Effects of Known Unknowns on Inferred High-redshift Galaxy Properties: Burstiness, the IMF, and Nebular Physics

Abstract

The era of the James Webb Space Telescope ushers stellar population models into uncharted territories, particularly at the high-redshift frontier. In a companion paper, we apply the \texttt{Prospector} Bayesian framework to jointly infer galaxy redshifts and stellar population properties from broad-band photometry as part of the UNCOVER survey. Here we present a comprehensive error budget in spectral energy distribution (SED) modeling. Using a sample selected to have photometric redshifts higher than 9, we quantify the systematic shifts stemming from various model choices in inferred stellar mass, star formation rate (SFR), and age. These choices encompass different timescales for changes in the star formation history (SFH), non-universal stellar initial mass functions (IMF), and the inclusion of variable nebular abundances, gas density and ionizing photon budget. We find that the IMF exerts the strongest influence on the inferred properties: the systematic uncertainties can be as much as 1 dex, 2--5 times larger than the formal reported uncertainties in mass and SFR; and importantly, exceed the scatter seen when using different SED fitting codes. Although the assumptions on the lower end of the IMF induce degeneracy, our findings suggest that a common practice in the literature of assessing uncertainties in SED-fitting processes by comparing multiple codes is substantively underestimating the true systematic uncertainty. Highly stochastic SFHs change the inferred SFH by much larger than the formal uncertainties, and introduce $\sim 0.8$ dex systematics in SFR averaged over short time scale and $\sim 0.3$ dex systematics in average age. Finally, employing a flexible nebular emission model causes $\sim 0.2$ dex systematic increase in mass and SFR, comparable to the formal uncertainty. This paper constitutes an initial step toward a complete uncertainty estimate in SED modeling.

arXiv commentAccepted for publication in ApJ. 22 pages, 10 figures, 2 tables

References in corpus (117)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• Galactic Stellar and Substellar Initial Mass Function
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• On the variation of the Initial Mass Function
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• The Host Galaxies of AGN
• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• MESA Isochrones and Stellar Tracks (MIST) 0: Methods for the construction of stellar isochrones
• The propagation of uncertainties in stellar population synthesis modeling I: The relevance of uncertain aspects of stellar evolution and the IMF to the derived physical properties of galaxies
• The epochs of early-type galaxy formation as a function of environment
• New Insight on Galaxy Formation and Evolution from Keck Spectroscopy of the Hawaii Deep Fields
• MILES: A Medium resolution INT Library of Empirical Spectra
• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• Bayes in the sky: Bayesian inference and model selection in cosmology
• UniverseMachine: The Correlation between Galaxy Growth and Dark Matter Halo Assembly from z=0-10
• The propagation of uncertainties in stellar population synthesis modeling III: model calibration, comparison, and evaluation
• A Comprehensive Analysis of Uncertainties Affecting the Stellar Mass - Halo Mass Relation for 0<z<4
• A Universal Stellar Initial Mass Function? A Critical Look at Variations
• Modeling the Panchromatic Spectral Energy Distributions of Galaxies
• AGN Dusty Tori: II. Observational Implications of Clumpiness
• Inferring the star-formation histories of massive quiescent galaxies with BAGPIPES: Evidence for multiple quenching mechanisms
• The Atlas3D project - XX. Mass-size and mass-sigma distributions of early-type galaxies: bulge fraction drives kinematics, mass-to-light ratio, molecular gas fraction and stellar initial mass function
• Stellar Population Inference with Prospector
• The Frontier Fields: Survey Design
• AGN Dusty Tori: I. Handling of Clumpy Media
• A systematic variation of the stellar initial mass function in early-type galaxies
• The Stellar Populations and Evolution of Lyman Break Galaxies
• A population of red candidate massive galaxies ~600 Myr after the Big Bang
• How to Measure Galaxy Star Formation Histories II: Nonparametric Models
• A Comprehensive Study on Galaxies at z~9-16 Found in the Early JWST Data: UV Luminosity Functions and Cosmic Star-Formation History at the Pre-Reionization Epoch
• Deriving Physical Properties from Broadband Photometry with Prospector: Description of the Model and a Demonstration of its Accuracy Using 129 Galaxies in the Local Universe
• Nebular Emission from Star-Forming Galaxies
• The Stellar Initial Mass Function in Early-Type Galaxies From Absorption Line Spectroscopy. II. Results
• Two Remarkably Luminous Galaxy Candidates at $z\approx 10-12$ Revealed by JWST
• The evolution of the galaxy UV luminosity function at redshifts z ~ 8-15 from deep JWST and ground-based near-infrared imaging
• Modelling and interpreting spectral energy distributions of galaxies with BEAGLE
• Nebular Continuum and Line Emission in Stellar Population Synthesis Models
• The initial mass function of early-type galaxies
• JADES NIRSpec Spectroscopy of GN-z11: Lyman-$\alpha$ emission and possible enhanced nitrogen abundance in a $z=10.60$ luminous galaxy
• Spectral and Photometric Evolution of Young Stellar Populations: the Impact of Gaseous Emission at Various Metallicities
• A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ~ 12 Galaxy in Early JWST CEERS Imaging
• Early results from GLASS-JWST. III: Galaxy candidates at z$\sim$9-15
• Modelling the nebular emission from primeval to present-day star-forming galaxies
• Stress Testing $\Lambda$CDM with High-redshift Galaxy Candidates
• The infrared luminosity function of galaxies at redshifts z=1 and z~2 in the GOODS fields
• Dusty, Radiation Pressure Dominated Photoionization. I. Model Description, Structure And Grids
• The galaxy stellar mass function at 3.5<z<7.5 in the CANDELS/UDS, GOODS-South, and HUDF fields
• Evolution of Density Profiles in High-z Galaxies: Compaction and Quenching Inside-Out
• Evidence for Ubiquitous, High-EW Nebular Emission in z~7 Galaxies: Towards a Clean Measurement of the Specific Star Formation Rate using a Sample of Bright, Magnified Galaxies
• Stellar masses from the CANDELS survey: the GOODS-South and UDS fields
• The GLASS James Webb Space Telescope Early Release Science Program. I. Survey Design and Release Plans
• An Older, More Quiescent Universe from Panchromatic SED Fitting of the 3D-HST Survey
• Galaxy And Mass Assembly (GAMA): The star formation rate dependence of the stellar initial mass function
• On the stunning abundance of super-early, massive galaxies revealed by JWST
• Revealing Galaxy Candidates out to $z\sim 16$ with JWST Observations of the Lensing Cluster SMACS0723
• The brightest galaxies at Cosmic Dawn
• On the Stellar Populations of Galaxies at z=9-11: The Growth of Metals and Stellar Mass at Early Times
• Confirmation and refutation of very luminous galaxies in the early universe
• The Stellar Initial Mass Function of Ultra-Faint Dwarf Galaxies: Evidence for IMF Variations with Galactic Environment
• A JWST/NIRCam Study of Key Contributors to Reionization: The Star-forming and Ionizing Properties of UV-faint $z\sim 7-8$ Galaxies
• Radial variations in the stellar initial mass function of early-type galaxies
• Chemistry of the Sagittarius Dwarf Galaxy: a Top-Light IMF, Outflows and the R-Process
• The Art of Measuring Physical Parameters in Galaxies: A Critical Assessment of Spectral Energy Distribution Fitting Techniques
• The Stellar Initial Mass Function in Early-Type Galaxies from Absorption Line Spectroscopy. III. Radial Gradients
• The impact of the metallicity and star formation rate on the time-dependent galaxy-wide stellar initial mass function
• High-precision Photometric Redshifts from Spitzer/IRAC: Extreme [3.6]-[4.5] Colors Identify Galaxies in the Redshift Range z~6.6-6.9
• Evolution of the UV LF from z~15 to z~8 Using New JWST NIRCam Medium-Band Observations over the HUDF/XDF
• Life beyond 30: probing the -20<M_UV<-17 luminosity function at 8<z<13 with the NIRCam parallel field of the MIRI Deep Survey
• PopStar I: Evolutionary synthesis models description
• A Model for the Origin of Bursty Star Formation in Galaxies
• Dusty Starbursts Masquerading as Ultra-high Redshift Galaxies in JWST CEERS Observations
• A New Census of the 0.2 < z < 3.0 Universe, Part I: The Stellar Mass Function
• Variations of the stellar initial mass function in the progenitors of massive early-type galaxies and in extreme starburst environments
• Early Results from GLASS-JWST. XIX: A High Density of Bright Galaxies at $z\approx 10$ in the Abell 2744 Region
• Are the ultra-high-redshift galaxies at z > 10 surprising in the context of standard galaxy formation models?
• The Stellar Initial Mass Function in Early-Type Galaxies From Absorption Line Spectroscopy. I. Data and Empirical Trends
• UNCOVERing the extended strong lensing structures of Abell 2744 with the deepest JWST imaging
• Stochastic star formation in early galaxies: JWST implications
• Star formation histories of UV-luminous galaxies at $z\simeq 6.8$: implications for stellar mass assembly at early cosmic times
• The stellar initial mass function of early type galaxies from low to high stellar velocity dispersion: homogeneous analysis of ATLAS${}^{3D}$ and Sloan Lens ACS galaxies
• Hot dust in Panchromatic SED Fitting: Identification of AGN and improved galaxy properties
• The Bursty Star Formation Histories of Low-mass Galaxies at $0.4<z<1$ Revealed by Star Formation Rates Measured from H$\beta$ and FUV
• UNCOVER: Illuminating the Early Universe -- JWST/NIRSpec Confirmation of $z>12$ Galaxies
• The Importance of Nebular Continuum and Line Emission in Observations of Young Massive Star Clusters
• Templates for Fitting Photometry of Ultra-High-Redshift Galaxies
• On the importance of using appropriate spectral models to derive physical properties of galaxies at 0.7<z<2.8
• JWST UNCOVER: Discovery of $z>9$ Galaxy Candidates Behind the Lensing Cluster Abell 2744
• First Insights into the ISM at $z>8$ with JWST: Possible Physical Implications of a High [O III]$\lambda 4363$/[O III]$\lambda 5007$
• Blue Monsters. Why are JWST super-early, massive galaxies so blue?
• The Stellar Initial Mass Function in Early-Type Galaxies From Absorption Line Spectroscopy. IV. A Super-Salpeter IMF in the center of NGC 1407 from Non-Parametric Models
• Primordial power spectrum in light of JWST observations of high redshift galaxies
• Mini-quenching of $z=4-8$ galaxies by bursty star formation
• Recovering the star formation histories of recently-quenched galaxies: the impact of model and prior choices
• RASCAS: RAdiation SCattering in Astrophysical Simulations
• Inferring More from Less: Prospector as a Photometric Redshift Engine in the Era of JWST
• Resonant line transfer in a fog: Using Lyman-alpha to probe tiny structures in atomic gas
• Impact of the cosmic background radiation on the initial mass function of metal-poor stars
• Deep ALMA redshift search of a z~12 GLASS-JWST galaxy candidate
• The UNCOVER Survey: A First-look HST+JWST Catalog of Galaxy Redshifts and Stellar Population Properties Spanning $0.2\lesssim z\lesssim 15$
• The Nature of High ${[\mathrm{OIII}]}_{88\mu \mathrm{m}}$/${[\mathrm{CII}]}_{158\mu \mathrm{m}}$ Galaxies in the Epoch of Reionization: Low Carbon Abundance and a Top-Heavy IMF?
• Alleviating the need for exponential evolution of JWST galaxies in 10${}^{10}{M}_{\odot }$ haloes at $z>10$ by a modified $\Lambda$CDM power spectrum
• How robustly can we constrain the low-mass end of the $z\sim 6-7$ stellar mass function? -- The limits of lensing models and stellar population assumptions in the Hubble Frontier Fields
• Are the Newly-Discovered $z\sim 13$ Drop-out Sources Starburst Galaxies or Quasars?
• Fuzzy Dark Matter as a Solution to Reconcile the Stellar Mass Density of High-z Massive Galaxies and Reionization History
• SBI++: Flexible, Ultra-fast Likelihood-free Inference Customized for Astronomical Applications
• Chemical evolution of elliptical galaxies with a variable IMF -- A publicly available code
• Forward modeling of galaxy populations for cosmological redshift distribution inference
• Broad emission lines in optical spectra of hot dust-obscured galaxies can contribute significantly to JWST/NIRCam photometry
• AstraeusIV : Quantifying the star formation histories of galaxies in the Epoch of Reionization
• PopSED: Population-Level Inference for Galaxy Properties from Broadband Photometry with Neural Density Estimation
• Flexible Models for Galaxy Star Formation Histories Both Shift and Scramble the Optical Color-M/L Relationship
• Objects in JWST's mirrors are closer than they appear

Cited by in corpus (29)

• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• Spectroscopic confirmation of two luminous galaxies at $z\sim 14$
• RUBIES: Evolved Stellar Populations with Extended Formation Histories at $z\sim 7-8$ in Candidate Massive Galaxies Identified with JWST/NIRSpec
• EPOCHS IV: SED Modelling Assumptions and their impact on the Stellar Mass Function at 6.5 < z < 13.5 using PEARLS and public JWST observations
• Galaxy Mergers in the Epoch of Reionization I: A JWST Study of Pair Fractions, Merger Rates, and Stellar Mass Accretion Rates at $z=4.5-11.5$
• Dust attenuation evolution in $z\sim 2$-$12$ JWST galaxies
• Outshining in the Spatially Resolved Analysis of a Strongly-Lensed Galaxy at z=6.072 with JWST NIRCam
• Exploring a primordial solution for early black holes detected with the JWST
• The effect of the environment-dependent stellar initial mass function on the photometric properties of star-forming galaxies
• JWST/MIRI reveals the true number density of massive galaxies in the early Universe
• How do Primordial Black Holes change the Halo Mass Function and Structure?
• Not-so-little Red Dots: Two massive and dusty starbursts at z~5-7 pushing the limits of star formation discovered by JWST in the COSMOS-Web survey
• Variation of the low-mass end of the stellar initial mass function with redshift and metallicity
• Impact of stellar population synthesis choices on forward modelling-based redshift distribution estimates
• Behind the Spotlight: A systematic assessment of outshining using NIRCam medium-bands in the JADES Origins Field
• The properties of primordially-seeded black holes and their hosts in the first billion years: implications for JWST
• MAGAZ3NE: Massive, Extremely Dusty Galaxies at $z\sim 2$ Lead to Photometric Overestimation of Number Densities of the Most Massive Galaxies at $3<z<4$
• Galaxy Mergers in the Epoch of Reionization II: Major Merger-Triggered Star Formation and AGN Activities at $z=$ 4.5-8.5
• What is the nature of Little Red Dots and what is not, MIRI SMILES edition
• Importance of modelling the nebular continuum in galaxy spectra
• The ALPINE-ALMA [CII] Survey: Unveiling the baryon evolution in the ISM of $z\sim 5$ star-forming galaxies
• Taking a Break at Cosmic Noon: Continuum-selected Low-mass Galaxies Require Long Burst Cycles
• Dark Secrets of Baryons: Illuminating Dark Matter-Baryon Interactions with JWST
• ULTIMATE-deblending I. A 50-band Ultraviolet to Mid-infrared Photometric Catalog Combining Space- and Ground-based Data in the JWST/PRIMER survey
• A physically-motivated template set for high-z galaxy SED fitting
• The Cosmic Rush Hour: Rapid Formation of Bright, Massive, Disky, Star-Forming Galaxies as Signatures of Early-Universe Physics
• First statistical constraints on galactic scale outflows properties traced by their extended Mg II emission with MUSE
• pop-cosmos: Star formation over 12 Gyr from generative modelling of a deep infrared-selected galaxy catalogue
• GalSBI: Phenomenological galaxy population model for cosmology using simulation-based inference