Astro arXiv | astro-ph.CO

Line-of-sight effects in strong gravitational lensing by Pierre Fleury et al. on Wednesday 30 November While most strong-gravitational-lensing systems may be roughly modelled by a single massive object between the source and the observer, in the details all the structures near the light path contribute to the observed images. These additional contributions, known as line-of-sight effects, are non-negligible in practice. This article proposes a new theoretical framework to model the line-of-sight effects, together with very promising applications at the interface of weak and strong lensing. Our approach relies on the dominant-lens approximation, where one deflector is treated as the main lens while the others are treated as perturbations. The resulting framework is technically simpler to handle than the multi-plane lensing formalism, while allowing one to consistently model any sub-critical perturbation. In particular, it is not limited to the usual external-convergence and external-shear parameterisation. As a first application, we identify a specific notion of line-of-sight shear that is not degenerate with the ellipticity of the main lens, and which could thus be extracted from strong-lensing images. This result supports and improves the recent proposal that Einstein rings might be powerful probes of cosmic shear. As a second application, we investigate the distortions of strong-lensing critical curves under line-of-sight effects, and more particularly their correlations across the sky. We find that such correlations may be used to probe, not only the large-scale structure of the Universe, but also the dark-matter halo profiles of strong lenses. This last possibility would be a key asset to improve the accuracy of the measurement of the Hubble-Lema\^itre constant via time-delay cosmography. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2104.08883v5

Accurate modelling of extragalactic microlensing by compact objects by Víctor Boscá et al. on Wednesday 30 November Microlensing of extragalactic sources, in particular the probability of significant amplifications, is a potentially powerful probe of the abundance of compact objects outside the halo of the Milky Way. Accurate experimental constraints require an equally accurate theoretical model for the amplification statistics produced by such a population. In this article, we argue that the simplest (strongest-lens) model does not meet this demanding requirement. We thus propose an elaborate practical modelling scheme for extragalactic microlensing. We derive from first principles an expression for the amplification probability that consistently allows for: (i) the coupling between microlenses; (ii) realistic perturbations from the cosmic large-scale structure; (iii) extended-source corrections. An important conclusion is that the external shear applied on the dominant microlens, both by the other lenses and by the large-scale structure, is practically negligible. Yet, the predictions of our approach can still differ by a factor of a few with respect to existing models of the literature. Updated constraints on the abundance of compact objects accounting for such discrepancies may be required. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2205.00991v2

Constraints on dark matter annihilation and decay from the large-scale structure of the nearby universe by Deaglan J. Bartlett et al. on Wednesday 30 November Decaying or annihilating dark matter particles could be detected through gamma-ray emission from the species they decay or annihilate into. This is usually done by modelling the flux from specific dark matter-rich objects such as the Milky Way halo, Local Group dwarfs, and nearby groups. However, these objects are expected to have significant emission from baryonic processes as well, and the analyses discard gamma-ray data over most of the sky. Here we construct full-sky templates for gamma-ray flux from the large-scale structure within $\sim$200 Mpc by means of a suite of constrained $N$-body simulations (CSiBORG) produced using the Bayesian Origin Reconstruction from Galaxies algorithm. Marginalising over uncertainties in this reconstruction, small-scale structure, and parameters describing astrophysical contributions to the observed gamma-ray sky, we compare to observations from the Fermi Large Area Telescope to constrain dark matter annihilation cross sections and decay rates through a Markov Chain Monte Carlo analysis. We rule out the thermal relic cross section for $s$-wave annihilation for all $m_\chi \lesssim 7 {\rm \, GeV}/c^2$ at 95\% confidence if the annihilation produces gluons or quarks less massive than the bottom quark. We infer a contribution to the gamma-ray sky with the same spatial distribution as dark matter decay at $3.3\sigma$. Although this could be due to dark matter decay via these channels with a decay rate $\Gamma \approx 6 \times 10^{-28} {\rm \, s^{-1}}$, we find that a power-law spectrum of index $p=-2.75^{+0.71}_{-0.46}$, likely of baryonic origin, is preferred by the data. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2205.12916v2

Mirror Dark Sector Solution of the Hubble Tension with Time-varying Fine-structure Constant by John Zhang et al. on Wednesday 30 November We explore a model introduced by Cyr-Racine, Ge, and Knox (arXiv:2107.13000(2)) that resolves the Hubble tension by invoking a ``mirror world" dark sector with energy density a fixed fraction of the ``ordinary" sector of Lambda-CDM. Although it reconciles cosmic microwave background and large-scale structure observations with local measurements of the Hubble constant, the model requires a value of the primordial Helium mass fraction that is discrepant with observations and with the predictions of Big Bang Nucleosynthesis (BBN). We consider a variant of the model with standard Helium mass fraction but with the value of the electromagnetic fine-structure constant slightly different during photon decoupling from its present value. If $\alpha$ at that epoch is lower than its current value by $\Delta \alpha \simeq -2\times 10^{-5}$, then we can achieve the same Hubble tension resolution as in Cyr-Racine, et al. but with consistent Helium abundance. As an example of such time-evolution, we consider a toy model of an ultra-light scalar field, with mass $m <4\times 10^{-29}$ eV, coupled to electromagnetism, which evolves after photon decoupling and that appears to be consistent with late-time constraints on $\alpha$ variation. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.03236v2

Microlensing of gravitational waves by dark matter structures by Malcolm Fairbairn et al. on Wednesday 30 November Gravitational lensing of gravitational waves provides a potential new probe of dark matter structures. In this work, we consider the microlensing effect on gravitational wave signals from black hole binaries induced by low-mass dark matter halos that do not retain enough baryonic matter to hold stars. We clarify systematically when this microlensing effect is relevant and study in detail its detectability by future gravitational wave observatories. We consider lensing by cold dark matter halos and by solitonic cores that reside in fuzzy dark matter halos. Our results show that although the effect can be detectable at relatively large impact parameters, the probability of detecting such lensed events is low. In particular, we find that the expected number of events lensed by cold dark matter halos is $\mathcal{O}(0.01)$ per year for BBO and the expected number of events lensed by solitonic cores inside fuzzy dark matter halos is $\mathcal{O}(0.01)$ per year for ET. In the case that a significant fraction of dark matter consists of $\mathcal{O}(100 M_\odot)$ objects that are relatively compact, $R < \mathcal{O}(0.1\,{\rm pc})$, we show that the expected number of lensed events per year ET can be very large, $\mathcal{O}(1000)$. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.13436v2

A bias-free cosmological analysis with quasars alleviating H 0 tension by Aleksander Łukasz Lenart et al. on Wednesday 30 November Cosmological models and their parameters are widely debated because of theoretical and observational mismatches of the standard cosmological model, especially the current discrepancy between the value of the Hubble constant, $H_{0}$, obtained by Type Ia supernovae (SNe Ia), and the Cosmic Microwave Background Radiation (CMB). Thus, considering high-redshift probes like quasars (QSOs), having intermediate redshifts between SNe Ia and CMB, is a necessary step. In this work, we use SNe Ia and the most updated QSO sample, reaching redshifts up to $z\sim7.5$, applying the Risaliti-Lusso QSO relation based on a non-linear relation between ultraviolet and X-ray luminosities. We consider this relation both in its original form and corrected for selection biases and evolution in redshift through a reliable statistical method also accounting for the circularity problem. We also explore two approaches: with and without calibration on SNe Ia. We then investigate flat and non-flat standard cosmological models and a flat $w$CDM model, with a constant dark energy equation of state parameter $w$. Remarkably, when correcting for the evolution as a function of cosmology, we obtain closed constraints on $\Omega_M$ using only non-calibrated QSOs. We find that considering non-calibrated QSOs combined with SNe Ia and accounting for the same correction, our results are compatible with a flat $\Lambda$CDM model with $\Omega_M = 0.3$ and $H_0 = 70 \, \mathrm{km\,s^{-1}\,Mpc^{-1}}$. Intriguingly, the $H_0$ values obtained place halfway between the one from SNe Ia and CMB, paving the way for new insights into the $H_0$ tension. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.10785v2

Free-form reconstruction of primordial power spectrum using Planck CMB temperature and polarization by Wuhyun Sohn et al. on Wednesday 30 November We present a free-form reconstruction of the primordial power spectrum using Planck 2018 CMB temperature and polarisation data. We extend the modified Richardson-Lucy (MRL) algorithm to include polarisation and apply it to the CamSpec unbinned $C_\ell$s. Combined with a new regularisation technique inspired by the diffusion equation, we obtain a form of primordial power spectrum with features that improve the fit to each of TT, TE, and EE data simultaneously. The resulting features are consistent with the previous findings from the temperature-only analyses. We evaluate the statistical significance of the features in our reconstructions using simulated $C_\ell$s and find the data to be consistent with having a featureless primordial power spectrum. The machinery developed here will be a complimentary tool in the search for features in the primordial power spectrum with upcoming CMB surveys. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15139v2

Gravity in the Local Universe : density and velocity fields using CosmicFlows-4 by H. M. Courtois et al. on Wednesday 30 November This article publicly releases three-dimensional reconstructions of the local Universe gravitational field below z=0.8 that were computed using the full catalogue CosmicFlows-4 of 56,000 galaxy distances and its sub-sample of 1,008 type Ia supernovae distances. The article also provides some first CF4 measurements of the growth rate of structure using the pairwise correlation of peculiar velocities fsigma8 = 0.44(+/-0.01) and of the bulk flow in the Local Universe of 200+/-88 kms-1 at distance 300 h-1Mpc. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16390v1

Palatini formulation for gauge theory: implications for slow-roll inflation by Syksy Rasanen et al. on Wednesday 30 November We consider a formulation of gauge field theory where the gauge field $A_\alpha$ and the field strength $F_{\alpha\beta}$ are independent variables, as in the Palatini formulation of gravity. For the simplest gauge field action, this is known to be equivalent to the usual formulation. We add non-minimal couplings between $F_{\alpha\beta}$ and a scalar field, solve for $F_{\alpha\beta}$ and insert it back into the action. This leads to modified gauge field and scalar field terms. We consider slow-roll inflation and show that because of the modifications to the scalar sector, adding higher order terms to the inflaton potential does not spoil its flatness, unlike in the usual case. Instead they make the effective potential closer to quadratic. The modifications also solve the problem that Higgs inflation in the Palatini formulation is sensitive to higher order terms. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15584v1

Sensitivity of strong lensing observations to dark matter substructure: a case study with Euclid by Conor M. O'Riordan et al. on Wednesday 30 November We introduce a machine learning method for estimating the sensitivity of strong lens observations to dark matter subhaloes in the lens. Our training data include elliptical power-law lenses, Hubble Deep Field sources, external shear, and noise and PSF for the Euclid VIS instrument. We set the concentration of the subhaloes using a $v_\mathrm{max}$-$r_\mathrm{max}$ relation. We then estimate the dark matter subhalo sensitivity in $16{,}000$ simulated strong lens observations with depth and resolution resembling Euclid VIS images. We find that, with a $3\sigma$ detection threshold, $2.35$ per cent of pixels inside twice the Einstein radius are sensitive to subhaloes with a mass $M_\mathrm{max}\leq 10^{10}M_\odot$, $0.03$ per cent are sensitive to $M_\mathrm{max}\leq 10^{9}M_\odot$, and, the limit of sensitivity is found to be $M_\mathrm{max}=10^{8.8\pm0.2}M_\odot$. Using our sensitivity maps and assuming CDM, we estimate that Euclid-like lenses will yield $1.43^{+0.14}_{-0.11}[f_\mathrm{sub}^{-1}]$ detectable subhaloes per lens in the entire sample, but this increases to $35.6^{+0.9}_{-0.9}[f_\mathrm{sub}^{-1}]$ per lens in the most sensitive lenses. Estimates are given in units of the inverse of the substructure mass fraction $f_\mathrm{sub}^{-1}$. Assuming $f_\mathrm{sub}=0.01$, one in every $70$ lenses in general should yield a detection, or one in every $\sim$ three lenses in the most sensitive sample. From $170,000$ new strong lenses detected by Euclid, we expect $\sim 2500$ new subhalo detections. We find that the expected number of detectable subhaloes in warm dark matter models only changes relative to cold dark matter for models which have already been ruled out, i.e., those with half-mode masses $M_\mathrm{hm}>10^8M_\odot$. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15679v1

Weak Lensing Tomographic Redshift Distribution Inference for the Hyper Suprime-Cam Subaru Strategic Program three-year shape catalogue by Markus Michael Rau et al. on Wednesday 30 November We present posterior sample redshift distributions for the Hyper Suprime-Cam Subaru Strategic Program Weak Lensing three-year (HSC Y3) analysis. Using the galaxies' photometry and spatial cross-correlations, we conduct a combined Bayesian Hierarchical Inference of the sample redshift distributions. The spatial cross-correlations are derived using a subsample of Luminous Red Galaxies (LRGs) with accurate redshift information available up to a photometric redshift of $z < 1.2$. We derive the photometry-based constraints using a combination of two empirical techniques calibrated on spectroscopic- and multiband photometric data that covers a spatial subset of the shear catalog. The limited spatial coverage induces a cosmic variance error budget that we include in the inference. Our cross-correlation analysis models the photometric redshift error of the LRGs to correct for systematic biases and statistical uncertainties. We demonstrate consistency between the sample redshift distributions derived using the spatial cross-correlations, the photometry, and the posterior of the combined analysis. Based on this assessment, we recommend conservative priors for sample redshift distributions of tomographic bins used in the three-year cosmological Weak Lensing analyses. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16516v1

X-ray Absorption Lines in the Warm-Hot Intergalactic Medium: Probing Chandra observations with the CAMEL simulations by Amanda Butler Contreras et al. on Wednesday 30 November Known as the "Missing Baryon Problem", about one-third of baryons in the local universe remain unaccounted for. The missing baryons are thought to reside in the warm-hot intergalactic medium (WHIM) of the cosmic web filaments, which are challenging to detect. Recent Chandra X-ray observations from Kov\'acs et al. (2019) used a novel stacking analysis and detected an OVII absorption line toward the sightline of a luminous quasar, hinting that the missing baryons may reside in the WHIM. To explore how the properties of the OVII absorption line depend on feedback physics, we compare the observational results with predictions obtained from the Cosmology and Astrophysics with MachinE Learning (CAMEL) Simulation suite. CAMELS consists of cosmological simulations with state-of-the-art supernova (SN) and active galactic nuclei (AGN) feedback models from the IllustrisTNG and SIMBA simulations, with varying strengths. We find that the simulated OVII column densities are higher in the outskirts of galaxies than in the large-scale WHIM, but they are consistently lower than those obtained in the Chandra observations, for all feedback runs. We establish that the OVII distribution is primarily sensitive to changes in the SN feedback prescription, whereas changes in the AGN feedback prescription have minimal impact. We also find significant differences in the OVII column densities between the IllustrisTNG and SIMBA runs. We conclude that the tension between the observed and simulated OVII column densities cannot be explained by the wide range of feedback models implemented in CAMELS. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15675v1

Primordial Black Hole Formation during a Strongly Coupled Crossover by Albert Escrivà et al. on Wednesday 30 November The final mass distribution of primordial black holes is sensitive to the equation of state of the Universe at the scales accessible by the power spectrum. Motivated by the presence of phase transitions in several beyond the Standard Model theories, some of which are strongly coupled, we analyse the production of primordial black holes during such phase transitions, which we model using the gauge/gravity duality. We focus in the (often regarded as physically uninteresting) case for which the phase transition is just a smooth crossover. We find an enhancement of primordial black hole production in the range $M_{\rm{PBH}}\in[10^{-16},10^{-6}]M_{\odot}$. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15674v1

Toward Accurate Modeling of Galaxy Clustering on Small Scales: Halo Model Extensions & Lingering Tension by Gillian D. Beltz-Mohrmann et al. on Wednesday 30 November This paper represents an effort to provide robust constraints on cosmology and the galaxy-halo connection using a fully numerical model of small-scale galaxy clustering. We explore two extensions to the standard Halo Occupation Distribution model: assembly bias, whereby halo occupation depends on both halo mass and the larger environment, and velocity bias, whereby galaxy velocities do not perfectly trace the velocity of the dark matter within the halo. Moreover, we incorporate halo mass corrections to account for the impact of baryonic physics on the halo population. We identify an optimal set of clustering measurements to constrain this "decorated" HOD model for both low- and high-luminosity galaxies in SDSS DR7. We find that, for low-luminosity galaxies, a model with both assembly bias and velocity bias provides the best fit to the clustering measurements, with no tension remaining in the fit. In this model we find evidence for both central and satellite galaxy assembly bias at the 99% and 95% confidence levels, respectively. In addition, we find evidence for satellite galaxy velocity bias at the 99.9% confidence level. For high luminosity galaxies, we find no evidence for either assembly bias or velocity bias, but our model exhibits significant tension with SDSS measurements. We find that all of these conclusions still stand when we include the effects of baryonic physics on the halo mass function, suggesting that the tension we find for high luminosity galaxies may be due to a problem with our assumed cosmological model. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16105v1

The Second Radio Synchrotron Background Workshop: Conference Summary and Report by J. Singal et al. on Wednesday 30 November We summarize the second radio synchrotron background workshop, which took place June 15-17, 2022 in Barolo, Italy. This meeting was convened because available measurements of the diffuse radio zero level continue to suggest that it is several times higher than can be attributed to known Galactic and extragalactic sources and processes, rendering it the least well understood electromagnetic background at present and a major outstanding question in astrophysics. The workshop agreed on the next priorities for investigations of this phenomenon, which include searching for evidence of the Radio Sunyaev-Zeldovich effect, carrying out cross-correlation analyses of radio emission with other tracers, and supporting the completion of the 310 MHz absolutely calibrated sky map project. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16547v1

The Dark Energy Survey Year 3 high redshift sample: Selection, characterization and analysis of galaxy clustering by C. Sánchez et al. on Wednesday 30 November The fiducial cosmological analyses of imaging galaxy surveys like the Dark Energy Survey (DES) typically probe the Universe at redshifts $z < 1$. This is mainly because of the limited depth of these surveys, and also because such analyses rely heavily on galaxy lensing, which is more efficient at low redshifts. In this work we present the selection and characterization of high-redshift galaxy samples using DES Year 3 data, and the analysis of their galaxy clustering measurements. In particular, we use galaxies that are fainter than those used in the previous DES Year 3 analyses and a Bayesian redshift scheme to define three tomographic bins with mean redshifts around $z \sim 0.9$, $1.2$ and $1.5$, which significantly extend the redshift coverage of the fiducial DES Year 3 analysis. These samples contain a total of about 9 million galaxies, and their galaxy density is more than 2 times higher than those in the DES Year 3 fiducial case. We characterize the redshift uncertainties of the samples, including the usage of various spectroscopic and high-quality redshift samples, and we develop a machine-learning method to correct for correlations between galaxy density and survey observing conditions. The analysis of galaxy clustering measurements, with a total signal-to-noise $S/N \sim 70$ after scale cuts, yields robust cosmological constraints on a combination of the fraction of matter in the Universe $\Omega_m$ and the Hubble parameter $h$, $\Omega_m = 0.195^{+0.023}_{-0.018}$, and 2-3% measurements of the amplitude of the galaxy clustering signals, probing galaxy bias and the amplitude of matter fluctuations, $b \sigma_8$. A companion paper $\textit{(in preparation)}$ will present the cross-correlations of these high-$z$ samples with CMB lensing from Planck and SPT, and the cosmological analysis of those measurements in combination with the galaxy clustering presented in this work. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16593v1

Accelerating BAO Scale Fitting Using Taylor Series by Matthew Hansen et al. on Wednesday 30 November The Universe is currently undergoing accelerated expansion driven by dark energy. Dark energy's essential nature remains mysterious: one means of revealing it is by measuring the Universe's size at different redshifts. This may be done using the Baryon Acoustic Oscillation (BAO) feature, a standard ruler in the galaxy 2-Point Correlation Function (2PCF). In order to measure the distance scale, one dilates and contracts a template for the 2PCF in a fiducial cosmology, using a scaling factor $\alpha$. The standard method for finding the best-fit $\alpha$ is to compute the likelihood over a grid of roughly 100 values of it. This approach is slow; in this work, we propose a significantly faster way. Our method writes the 2PCF as a polynomial in $\alpha$ by Taylor-expanding it about $\alpha = 1$, exploiting that we know the fiducial cosmology sufficiently well that $\alpha$ is within a few percent of unity. The likelihood resulting from this expansion may then be analytically solved for the best-fit $\alpha$. Our method is 48-85$\times$ faster than a directly comparable approach in which we numerically minimize $\alpha$, and $\sim$$12,000 \times$ faster than the standard iterative method. Our work will be highly enabling for upcoming large-scale structure redshift surveys such as that by Dark Energy Spectroscopic Instrument (DESI). arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2112.06438v2

Using simulated Tianqin gravitational wave data and electromagnetic wave data to study the coincidence problem and Hubble tension problem by JiaWei Zhang et al. on Wednesday 30 November In this paper, we use electromagnetic wave data (H0LiCOW, $H(z)$, SNe) and gravitational wave data (Tianqin) to constrain the interacting dark energy (IDE) model and investigate the Hubble tension problem and coincidences problem. By combining these four kinds of data (Tianqin+H0LiCOW+SNe+$H(z)$), we obtained the parameter values at the confidence interval of $1\sigma$: $\Omega_m=0.36\pm0.18$, $\omega_x=-1.29^{+0.61}_{-0.23}$, $\xi=3.15^{+0.36}_{-1.1}$, and $H_0=70.04\pm0.42$ $kms^{-1}Mpc^{-1}$. According to our results, the best valve of $H_0$ show that the Hubble tension problem can be alleviated to some extent. In addition, the $\xi+3\omega_x = -0.72^{+2.19}_{-1.19}(1\sigma)$ of which the center value indicates the coincidence problem is slightly alleviated. However, the $\xi+3\omega_x = 0$ is still within the $1\sigma$ error range which indicates the $\Lambda$CDM model is still the model which is in best agreement with the observational data at present. Finally, we compare the constraint results of electromagnetic wave and gravitational wave on the model parameters and find that the constraint effect of electromagnetic wave data on model parameters is better than that of simulated Tianqin gravitational wave data. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16979v1

Calibrating cosmological simulations with implicit likelihood inference using galaxy growth observables by Yongseok Jo et al. on Wednesday 30 November In a novel approach employing implicit likelihood inference (ILI), also known as likelihood-free inference, we calibrate the parameters of cosmological hydrodynamic simulations against observations, which has previously been unfeasible due to the high computational cost of these simulations. For computational efficiency, we train neural networks as emulators on ~1000 cosmological simulations from the CAMELS project to estimate simulated observables, taking as input the cosmological and astrophysical parameters, and use these emulators as surrogates to the cosmological simulations. Using the cosmic star formation rate density (SFRD) and, separately, stellar mass functions (SMFs) at different redshifts, we perform ILI on selected cosmological and astrophysical parameters (Omega_m, sigma_8, stellar wind feedback, and kinetic black hole feedback) and obtain full 6-dimensional posterior distributions. In the performance test, the ILI from the emulated SFRD (SMFs) can recover the target observables with a relative error of 0.17% (0.4%). We find that degeneracies exist between the parameters inferred from the emulated SFRD, confirmed with new full cosmological simulations. We also find that the SMFs can break the degeneracy in the SFRD, which indicates that the SMFs provide complementary constraints for the parameters. Further, we find that the parameter combination inferred from an observationally-inferred SFRD reproduces the target observed SFRD very well, whereas, in the case of the SMFs, the inferred and observed SMFs show significant discrepancies that indicate potential limitations of the current galaxy formation modeling and calibration framework, and/or systematic differences and inconsistencies between observations of the stellar mass function. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16461v1

Potential contributions of Pop III and intermediate-mass Pop II stars to cosmic chemical enrichment by Lia C. Corazza et al. on Wednesday 30 November We propose a semi-analytic model that is developed to understand the cosmological evolution of the mean metallicity in the Universe. In particular, we study the contributions of Population III (Pop III) and Population II (Pop II) stars to the production of $\mathrm{Fe,~Si,~Zn, ~Ni,~P, ~Mg, ~Al, ~S, ~C, ~N}$, and $\mathrm{~O}$. We aim to quantify the roles of two different models in the chemical enrichment of the Universe. The first model (A) considers both stars with Pop III and Pop II yields. For the second model (B), the yields involved are only for Pop II stars. We start by describing the cosmic star formation rate (CSFR) through an adaptation of a scenario developed within the hierarchical scenario of structure formation with a Press-Schechter-like formalism. We adapt the formalism to implement the CSFR to the standard chemical evolution scenario to investigate the course of chemical evolution on a cosmological basis. Calculations start at redshift $z\sim 20$, and we compare the results of our two models with data from damped Lyman-$\alpha$ systems (DLAs), and globular clusters (GCs). Our main results find that metal production in the Universe occurred very early, quickly increasing with the formation of the first stars. When comparing results for [Fe/H] with observations from GCs, yields of Pop II stars are not enough to explain the observed chemical abundances, requiring stars with physical properties similar those expected from Pop III stars. Our semi-analytic model can deliver consistent results for the evolution of cosmic metallicities. Our results show that the chemical enrichment in the early Universe is rapid, and at redshift $\sim 12.5$, the metallicity reaches $10^{-4}\, Z_{\odot}$ for the model that includes Pop III stars. In addition, we explore values for the initial mass function (IMF) within the range $[0.85, 1.85]$. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15828v1