SPECULATOR: Emulating Stellar Population Synthesis for Fast and Accurate Galaxy Spectra and Photometry

Alsing, Justin; Peiris, Hiranya V.; Leja, Joel; Hahn, ChangHoon; Tojeiro, Rita; Mortlock, D.; Leistedt, Boris; Johnson, Benjamin D.; Conroy, Charlie

doi:10.3847/1538-4365/ab917f

Cited by 61 publications

(90 citation statements)

References 44 publications

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“…These interior abundance profiles matter: they impact a star's opacity, thermodynamics, nuclear energy generation, and pulsation properties. The stellar models, in turn, are used to interpret the integrated light of stellar clusters and galaxies (e.g., Alsing et al 2020), decipher the origin of the elements (e.g., Arcones et al 2017;Placco et al 2020), predict the frequency of merging neutron stars and black holes (Giacobbo & Mapelli 2018;Abbott et al 2020;Farmer et al 2020;Marchant & Moriya 2020), and decipher the population(s) of exploding white dwarfs (WDs) that underlay Type Ia supernova cosmology (e.g., Miles et al 2016;Rose et al 2020).…”

Section: Introductionmentioning

confidence: 99%

On the Impact of ²²Ne on the Pulsation Periods of Carbon–Oxygen White Dwarfs with Helium-dominated Atmospheres

Chidester

Timmes

Schwab

et al. 2021

ApJ

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We explore changes in the adiabatic low-order g-mode pulsation periods of 0.526, 0.560, and 0.729 M ⊙ carbon–oxygen white dwarf models with helium-dominated envelopes due to the presence, absence, and enhancement of 22Ne in the interior. The observed g-mode pulsation periods of such white dwarfs are typically given to 6−7 significant figures of precision. Usually white dwarf models without 22Ne are fit to the observed periods and other properties. The rms residuals to the ≃150−400 s low-order g-mode periods are typically in the range of σ rms ≲ 0.3 s, for a fit precision of σ rms/P ≲ 0.3%. We find average relative period shifts of ΔP/P ≃ ±0.5% for the low-order dipole and quadrupole g-mode pulsations within the observed effective temperature window, with the range of ΔP/P depending on the specific g-mode, abundance of 22Ne, effective temperature, and the mass of the white dwarf model. This finding suggests a systematic offset may be present in the fitting process of specific white dwarfs when 22Ne is absent. As part of the fitting processes involves adjusting the composition profiles of a white dwarf model, our study on the impact of 22Ne can provide new inferences on the derived interior mass fraction profiles. We encourage routinely including 22Ne mass fraction profiles, informed by stellar evolution models, to future generations of white dwarf model-fitting processes.

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Section: Introductionmentioning

confidence: 99%

On the Impact of ²²Ne on the Pulsation Periods of Carbon–Oxygen White Dwarfs with Helium-dominated Atmospheres

Chidester

Timmes

Schwab

et al. 2021

ApJ

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“…For photometry with small observational uncertainties, a 5 % error floor is put in place. This is to account for systematic model uncertainties as stellar population models are products of an amalgamation of theory, empirical libraries, and occasionally, ad-hoc assumptions (Conroy et al 2009;Conroy 2013;Leja et al 2019b;Alsing et al 2020).…”

Section: Sed Modelingmentioning

confidence: 99%

Physical Properties of the Host Galaxies of Ca-rich Transients

Dong,

Milisavljevic,

Leja

et al. 2022

Preprint

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Calcium-rich (Ca-rich) transients are a new class of supernovae (SNe) that are known for their comparatively rapid evolution, modest peak luminosities, and strong nebular calcium emission lines. Currently, the progenitor systems of Ca-rich transients remain unknown. Although they exhibit spectroscopic properties not unlike core-collapse Type Ib/c SNe, nearly half are found in the outskirts of their host galaxies that are predominantly elliptical, suggesting a closer connection to the older stellar populations of SNe Ia. In this paper, we present a compilation of publicly available multiwavelength observations of all known and/or suspected host galaxies of Ca-rich transients ranging from FUV to IR, and use these data to characterize their stellar populations with prospector. We estimate several galaxy parameters including integrated star formation rate, stellar mass, metallicity, and age. For nine host galaxies, the observations are sensitive enough to obtain nonparametric star formation histories, from which we recover SN rates and estimate probabilities that the Ca-rich transients in each of these host galaxies originated from a core-collapse vs. Type Ia-like explosion. Our work supports the notion that the population of Ca-rich transients do not come exclusively from core-collapse explosions, and must either be only from white dwarf stars or a mixed population of white dwarf stars with other channels, potentially including massive star explosions. Additional photometry and explosion site spectroscopy of larger samples of Ca-rich host galaxies will improve these estimates and better constrain the ratio of white dwarf vs. massive star progenitors of Ca-rich transients.

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“…Emulation offers the promise of reducing the computational overhead of evaluating cosmological power spectra by many orders of magnitude, with negligible loss of accuracy in the final parameter inference. This surrogate modelling approach has recently seen numerous applications to the Bayesian solution of the inverse problem in different scientific fields, ranging from geophysical seismic waves (Das et al 2018;Spurio Mancini et al 2020;Piras et al 2021) to stel-★ a.spuriomancini@ucl.ac.uk lar and galaxy spectra (Czekala et al 2015;Alsing et al 2020), from chemical mechanisms (de Mĳolla et al 2019;Kasim et al 2020) to applied engineering (Thiagarajan et al 2020;Buffington et al 2020).…”

Section: Introductionmentioning

confidence: 99%

COSMOPOWER: emulating cosmological power spectra for accelerated Bayesian inference from next-generation surveys

Mancini,

Piras,

Alsing

et al. 2021

Preprint

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We present C P , a suite of neural cosmological power spectrum emulators providing orders-of-magnitude acceleration for parameter estimation from two-point statistics analyses of Large-Scale Structure (LSS) and Cosmic Microwave Background (CMB) surveys. The emulators replace the computation of matter and CMB power spectra from Boltzmann codes; thus, they do not need to be re-trained for different choices of astrophysical nuisance parameters or redshift distributions. The matter power spectrum emulation error is less than 0.4% in the wavenumber range 𝑘 ∈ [10 −5 , 10] Mpc −1 , for redshift 𝑧 ∈ [0, 5]. C P emulates CMB temperature, polarisation and lensing potential power spectra in the 5𝜎 region of parameter space around the Planck best fit values with an error 20% of the expected shot noise for the forthcoming Simons Observatory. C P is showcased on a joint cosmic shear and galaxy clustering analysis from the Kilo-Degree Survey, as well as on a Stage IV Euclid-like simulated cosmic shear analysis. For the CMB case, C P is tested on a Planck 2018 CMB temperature and polarisation analysis. The emulators always recover the fiducial cosmological constraints with differences in the posteriors smaller than sampling noise, while providing a speed-up factor up to 𝑂 (10 4 ) to the complete inference pipeline. This acceleration allows posterior distributions to be recovered in just a few seconds, as we demonstrate in the Planck likelihood case. C P is written entirely in P , can be interfaced with all commonly used cosmological samplers and is publicly available .

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SPECULATOR: Emulating Stellar Population Synthesis for Fast and Accurate Galaxy Spectra and Photometry

Cited by 61 publications

References 44 publications

On the Impact of ²²Ne on the Pulsation Periods of Carbon–Oxygen White Dwarfs with Helium-dominated Atmospheres

On the Impact of ²²Ne on the Pulsation Periods of Carbon–Oxygen White Dwarfs with Helium-dominated Atmospheres

Physical Properties of the Host Galaxies of Ca-rich Transients

COSMOPOWER: emulating cosmological power spectra for accelerated Bayesian inference from next-generation surveys

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SPECULATOR: Emulating Stellar Population Synthesis for Fast and Accurate Galaxy Spectra and Photometry

Cited by 61 publications

References 44 publications

On the Impact of 22Ne on the Pulsation Periods of Carbon–Oxygen White Dwarfs with Helium-dominated Atmospheres

On the Impact of 22Ne on the Pulsation Periods of Carbon–Oxygen White Dwarfs with Helium-dominated Atmospheres

Physical Properties of the Host Galaxies of Ca-rich Transients

COSMOPOWER: emulating cosmological power spectra for accelerated Bayesian inference from next-generation surveys

Contact Info

Product

Resources

About

On the Impact of ²²Ne on the Pulsation Periods of Carbon–Oxygen White Dwarfs with Helium-dominated Atmospheres

On the Impact of ²²Ne on the Pulsation Periods of Carbon–Oxygen White Dwarfs with Helium-dominated Atmospheres