Non-parametric Star Formation History Reconstruction with Gaussian Processes I: Counting Major Episodes of Star Formation

Abstract

The star formation histories (SFHs) of galaxies contain imprints of the physical processes responsible for regulating star formation during galaxy growth and quenching. We improve the Dense Basis SFH reconstruction method of Iyer & Gawiser (2017), introducing a nonparametric description of the SFH based on the lookback times at which a galaxy assembles certain quantiles of its stellar mass. The method uses Gaussian Processes to create smooth SFHs that are independent of any functional form, with a flexible number of parameters that is adjusted to extract the maximum possible amount of SFH information from the SEDs being fit. We apply the method to reconstruct the SFHs of 48,791 galaxies with $H<25$ at $0.5<z<3.0$ across the five CANDELS fields. Using these SFHs, we study the evolution of galaxies as they grow more massive over cosmic time. We quantify the fraction of galaxies that show multiple major episodes of star formation, finding that the median time between two peaks of star formation is $\sim 0.42_{-0.10}^{+0.15}{t}_{univ}$ Gyr, where $t_{univ}$ is the age of the universe at a given redshift and remains roughly constant with stellar mass. Correlating SFHs with morphology, we find that studying the median SFHs of galaxies at $0.5<z<1.0$ at the same mass ($10^{10}<M_{\ast }<10^{10.5}{M}_{\odot }$) allows us to compare the timescales on which the SFHs decline for different morphological classifications, ranging from $0.60_{+1.54}^{-0.54}$ Gyr for galaxies with spiral arms to $2.50_{+2.25}^{-1.50}$ Gyr for spheroids. The Gaussian Process-based SFH description provides a general approach to reconstruct smooth, nonparametric SFH posteriors for galaxies with a flexible number of parameters that can be incorporated into Bayesian SED fitting codes to minimize the bias in estimating physical parameters due to SFH parametrization.

26 pages, 15 figures. Submitted to ApJ

References in corpus (31)

• Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
• Star Formation in AEGIS Field Galaxies since z=1.1 : The Dominance of Gradually Declining Star Formation, and the Main Sequence of Star-Forming Galaxies
• 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 hierarchical formation of the brightest cluster galaxies
• A simple model to interpret the ultraviolet, optical and infrared emission from galaxies
• A Semi-Analytic Model for the Co-evolution of Galaxies, Black Holes, and Active Galactic Nuclei
• Constraining the Low-Mass Slope of the Star Formation Sequence at 0.5<z<2.5
• The stellar mass assembly of galaxies from z=0 to z=4. Analysis of a sample selected in the rest-frame near-infrared with Spitzer
• Compaction and Quenching of High-z Galaxies in Cosmological Simulations: Blue and Red Nuggets
• The Evolution of Galaxy Structure over Cosmic Time
• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: II. Formation of Red Ellipticals
• Black Holes on FIRE: Stellar Feedback Limits Early Feeding of Galactic Nuclei
• Recovering galaxy star formation and metallicity histories from spectra using VESPA
• The star formation main sequence and stellar mass assembly of galaxies in the Illustris simulation
• Star Formation and the Growth of Stellar Mass
• SDSS-IV MaNGA: Spatially resolved star formation histories in galaxies as a function of galaxy mass and type
• Observational constraints on the merger history of galaxies since $z\approx 6$: Probabilistic galaxy pair counts in the CANDELS fields
• CANDELS Multiwavelength Catalogs: Source Identification and Photometry in the CANDELS COSMOS Survey Field
• Uncertainties in Parameters Estimated with Neural Networks: Application to Strong Gravitational Lensing
• On the SFR-M${}_{\ast }$ main sequence archetypal star-formation history and analytical models
• Stochastic modeling of star-formation histories I: the scatter of the star-forming main sequence
• SDSS IV MaNGA - The spatially resolved transition from star formation to quiescence
• Understanding the Structural Scaling Relations of Early-Type Galaxies
• SDSS-IV MANGA: Spatially Resolved Star Formation Main Sequence and LI(N)ER Sequence
• Major Merging History in CANDELS. I. Evolution of the Incidence of Massive Galaxy-Galaxy Pairs from z=3 to z~0
• The Slow Death (or Rebirth?) of Extended Star Formation in z~0.1 Green Valley Early-Type Galaxies
• Investigating H$\alpha$, UV, and IR star-formation rate diagnostics for a large sample of z ~ 2 galaxies
• Star Formation Stochasticity Measured from the Distribution of Burst Indicators
• Data-driven, interpretable photometric redshifts trained on heterogeneous and unrepresentative data
• Star formation histories from multi-band photometry: A new approach
• Demonstrating Diversity in Star Formation Histories with the CSI Survey

Cited by in corpus (17)

• An Atlas of Color-selected Quiescent Galaxies at $z>3$ in Public $JWST$ Fields
• Stochastic modelling of star-formation histories II: star-formation variability from molecular clouds and gas inflow
• The Diversity and Variability of Star Formation Histories in Models of Galaxy Evolution
• Beyond UVJ: More Efficient Selection of Quiescent Galaxies With UV / Mid-IR Fluxes
• The Sparkler: Evolved High-Redshift Globular Clusters Captured by JWST
• Recovering the star formation histories of recently-quenched galaxies: the impact of model and prior choices
• COSMOS2020: Exploring the dawn of quenching for massive galaxies at 3 < z < 5 with a new colour selection method
• A First Look at Spatially Resolved Balmer Decrements at $1.0<z<2.4$ from JWST NIRISS Slitless Spectroscopy
• An exquisitely deep view of quenching galaxies through the gravitational lens: Stellar population, morphology, and ionized gas
• Across the Green Valley with HST grisms: colour evolution, crossing time-scales and the growth of the red sequence at $z=1.0-1.8$
• Stellar populations and star formation histories of the most extreme [OIII] emitters at $z=1.3-3.7$
• Non-detection of ${}^6$Li in Spite plateau stars with ESPRESSO
• Bayesian hierarchical modelling of the ${\mathrm{M}}_{\star }$-SFR relation from 1<z<6 in ASTRODEEP
• A Multi-Wavelength Study of Star Formation in 15 Local Star-Forming Galaxies
• Improved Measurements of Galaxy Star Formation Stochasticity from the Intrinsic Scatter of Burst Indicators
• Detecting episodes of star formation using Bayesian model selection
• Downsizing revised: Star formation timescales for elliptical galaxies with an environment-dependent IMF and number of SNIa