scholarly journals Understanding galaxy formation in the reionization era using the FIRE simulations

2019 ◽  
Vol 15 (S352) ◽  
pp. 64-68
Author(s):  
Xiangcheng Ma
Keyword(s):  
Galaxy Formation ◽  
State Of The Art ◽  
High Redshift ◽  
Star Clusters ◽  
Mass Relation ◽  
High Redshift Galaxies ◽  
Stellar Feedback ◽  
Luminosity Functions ◽  
Multi Phase ◽  
Dust Attenuation

AbstractWe present a suite of high-resolution cosmological zoom-in simulations of galaxies at z⩾ 5using the state-of-the-art models for the multi-phase ISM, star formation, and stellar feedback from the FIRE project. We present a series of key results from these simulations, including the stellar mass–halo mass relation, the ultraviolet luminosity functions, dust attenuation and dust temperatures, the ubiquitous formation of bound star clusters, morphology and clumpiness, and the escape fractions of ionizing photons from high-redshift galaxies. We discuss how different simulations in the literature agree and disagree and what observations are most useful for testing the models in the era of ALMA and JWST.

scholarly journals High-redshift JWST predictions from IllustrisTNG: II. Galaxy line and continuum spectral indices and dust attenuation curves

2020 ◽  
Vol 495 (4) ◽  
pp. 4747-4768 ◽  
Author(s):  
Xuejian Shen ◽  
Mark Vogelsberger ◽  
Dylan Nelson ◽  
Annalisa Pillepich ◽  
Sandro Tacchella ◽  
...  
Keyword(s):  
High Redshift ◽  
Formation Rate ◽  
Spectral Indices ◽  
High Redshift Galaxies ◽  
Luminosity Functions ◽  
Galaxy Populations ◽  
Stellar Masses ◽  
Red Galaxies ◽  
Dust Attenuation ◽  
Rate Relation

ABSTRACT We present predictions for high redshift (z = 2−10) galaxy populations based on the IllustrisTNG simulation suite and a full Monte Carlo dust radiative transfer post-processing. Specifically, we discuss the H α and H β + $[\rm O \,{\small III}]$ luminosity functions up to z = 8. The predicted H β + $[\rm O \,{\small III}]$ luminosity functions are consistent with present observations at z ≲ 3 with ${\lesssim} 0.1\, {\rm dex}$ differences in luminosities. However, the predicted H α luminosity function is ${\sim }0.3\, {\rm dex}$ dimmer than the observed one at z ≃ 2. Furthermore, we explore continuum spectral indices, the Balmer break at 4000 Å; (D4000) and the UV continuum slope β. The median D4000 versus specific star formation rate relation predicted at z = 2 is in agreement with the local calibration despite a different distribution pattern of galaxies in this plane. In addition, we reproduce the observed AUV versus β relation and explore its dependence on galaxy stellar mass, providing an explanation for the observed complexity of this relation. We also find a deficiency in heavily attenuated, UV red galaxies in the simulations. Finally, we provide predictions for the dust attenuation curves of galaxies at z = 2−6 and investigate their dependence on galaxy colours and stellar masses. The attenuation curves are steeper in galaxies at higher redshifts, with bluer colours, or with lower stellar masses. We attribute these predicted trends to dust geometry. Overall, our results are consistent with present observations of high-redshift galaxies. Future James Webb Space Telecope observations will further test these predictions.

scholarly journals High-redshift JWST predictions from IllustrisTNG: dust modelling and galaxy luminosity functions

2020 ◽  
Vol 492 (4) ◽  
pp. 5167-5201 ◽  
Author(s):  
Mark Vogelsberger ◽  
Dylan Nelson ◽  
Annalisa Pillepich ◽  
Xuejian Shen ◽  
Federico Marinacci ◽  
...  
Keyword(s):  
Observational Data ◽  
Exposure Time ◽  
Cold Dark Matter ◽  
Rest Frame ◽  
Dynamic Range ◽  
High Redshift ◽  
Formation Rate ◽  
Mass Relation ◽  
Luminosity Functions ◽  
Dust Attenuation

ABSTRACT The James Webb Space Telescope (JWST) promises to revolutionize our understanding of the early Universe, and contrasting its upcoming observations with predictions of the Λ cold dark matter model requires detailed theoretical forecasts. Here, we exploit the large dynamic range of the IllustrisTNG simulation suite, TNG50, TNG100, and TNG300, to derive multiband galaxy luminosity functions from z = 2 to z = 10. We put particular emphasis on the exploration of different dust attenuation models to determine galaxy luminosity functions for the rest-frame ultraviolet (UV), and apparent wide NIRCam bands. Our most detailed dust model is based on continuum Monte Carlo radiative transfer calculations employing observationally calibrated dust properties. This calibration results in constraints on the redshift evolution of the dust attenuation normalization and dust-to-metal ratios yielding a stronger redshift evolution of the attenuation normalization compared to most previous theoretical studies. Overall we find good agreement between the rest-frame UV luminosity functions and observational data for all redshifts, also beyond the regimes used for the dust model calibrations. Furthermore, we also recover the observed high-redshift (z = 4–6) UV luminosity versus stellar mass relation, the H α versus star formation rate relation, and the H α luminosity function at z = 2. The bright end (MUV > −19.5) cumulative galaxy number densities are consistent with observational data. For the F200W NIRCam band, we predict that JWST will detect ∼80 (∼200) galaxies with a signal-to-noise ratio of 10 (5) within the NIRCam field of view, $2.2\times 2.2 \, {\rm arcmin}^{2}$, for a total exposure time of $10^5\, {\rm s}$ in the redshift range z = 8 ± 0.5. These numbers drop to ∼10 (∼40) for an exposure time of $10^4\, {\rm s}$.

scholarly journals Star Clusters Near and Far

2020 ◽  
Vol 216 (4) ◽  
Author(s):  
Angela Adamo ◽  
Peter Zeidler ◽  
J. M. Diederik Kruijssen ◽  
Mélanie Chevance ◽  
Mark Gieles ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Globular Clusters ◽  
High Redshift ◽  
Cluster Formation ◽  
Star Clusters ◽  
Local Universe ◽  
Stellar Feedback ◽  
Formation And Evolution ◽  
Numerical And Analytical Methods ◽  
Fundamental Units

Abstract Star clusters are fundamental units of stellar feedback and unique tracers of their host galactic properties. In this review, we will first focus on their constituents, i.e. detailed insight into their stellar populations and their surrounding ionised, warm, neutral, and molecular gas. We, then, move beyond the Local Group to review star cluster populations at various evolutionary stages, and in diverse galactic environmental conditions accessible in the local Universe. At high redshift, where conditions for cluster formation and evolution are more extreme, we are only able to observe the integrated light of a handful of objects that we believe will become globular clusters. We therefore discuss how numerical and analytical methods, informed by the observed properties of cluster populations in the local Universe, are used to develop sophisticated simulations potentially capable of disentangling the genetic map of galaxy formation and assembly that is carried by globular cluster populations.

scholarly journals Modeling high-redshift galaxies: what can we learn from high and ultra-high resolution hydrodynamical simulations?

2009 ◽  
Vol 5 (S262) ◽  
pp. 248-256
Author(s):  
J. Devriendt ◽  
A. Slyz ◽  
L. Powell ◽  
C. Pichon ◽  
R. Teyssier
Keyword(s):  
High Resolution ◽  
Galaxy Formation ◽  
Globular Clusters ◽  
High Redshift ◽  
Cosmological Parameters ◽  
High Redshift Galaxies ◽  
Luminosity Functions ◽  
Hydrodynamical Simulations ◽  
Consistent Treatment ◽  
Filamentary Material

AbstractWe present results from a high resolution cosmological galaxy formation simulation called Mare Nostrum and a ultra-high resimulation of the first 500 million years of a single, Milky Way (MW) sized galaxy. Using the cosmological run, we measure UV luminosity functions and assess their sensitivity to both cosmological parameters and dust extinction. We find remarkably good agreement with the existing data over the redshift range 4 < z < 7 provided we adopt the favoured cosmology (WMAP 5 year parameters) and a self-consistent treatment of the dust. Cranking up the resolution, we then study in detail a z = 9 protogalaxy sitting at the intersection of cold gas filaments. This high-z MW progenitor grows a dense, rapidly spinning, thin disk which undergoes gravitational fragmention. Star formation in the resulting gas clumps rapidly turns them into globular clusters. A far reaching galactic wind develops, co-powered by the protogalaxy and its cohort of smaller companions populating the filaments. Despite such an impressive blow out, the smooth filamentary material is hardly affected at these redshifts.

scholarly journals Dark-ages reionization and galaxy formation simulation – IV. UV luminosity functions of high-redshift galaxies

2016 ◽  
Vol 462 (1) ◽  
pp. 235-249 ◽  
Author(s):  
Chuanwu Liu ◽  
Simon J. Mutch ◽  
P. W. Angel ◽  
Alan R. Duffy ◽  
Paul M. Geil ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
High Redshift ◽  
High Redshift Galaxies ◽  
Dark Ages ◽  
Luminosity Functions ◽  
Redshift Galaxies

scholarly journals Dark-age reionization and galaxy formation simulation – XIX. Predictions of infrared excess and cosmic star formation rate density from UV observations

2019 ◽  
Vol 489 (1) ◽  
pp. 1357-1372 ◽  
Author(s):  
Yisheng Qiu ◽  
Simon J Mutch ◽  
Elisabete da Cunha ◽  
Gregory B Poole ◽  
J Stuart B Wyithe
Keyword(s):  
Star Formation ◽  
Galaxy Formation ◽  
Star Formation Rate ◽  
High Redshift ◽  
Formation Rate ◽  
Infrared Excess ◽  
Model Free ◽  
Luminosity Functions ◽  
The Difference ◽  
Dust Attenuation

ABSTRACT We present a new analysis of high-redshift UV observations using a semi-analytic galaxy formation model, and provide self-consistent predictions of the infrared excess (IRX)–β relations and cosmic star formation rate density. We combine the Charlot & Fall dust attenuation model with the meraxes semi-analytic model, and explore three different parametrizations for the dust optical depths, linked to star formation rate, dust-to-gas ratio, and gas column density, respectively. A Bayesian approach is employed to statistically calibrate model-free parameters including star formation efficiency, mass loading factor, dust optical depths, and reddening slope directly against UV luminosity functions and colour–magnitude relations at $z$ ∼ 4–7. The best-fitting models show excellent agreement with the observations. We calculate IRX using energy balance arguments and find that the large intrinsic scatter in the IRX–β plane correlates with specific star formation rate. Additionally, the difference among the three dust models suggests at least a factor of 2 systematic uncertainty in the dust-corrected star formation rate when using the Meurer IRX–β relation at $z$ ≳ 4.

scholarly journals Quasi-equilibrium models of high-redshift disc galaxy evolution

2020 ◽  
Vol 500 (3) ◽  
pp. 3394-3412
Author(s):  
Steven R Furlanetto
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Galaxy Formation ◽  
High Redshift ◽  
Formation Rate ◽  
New Physics ◽  
Small Scale ◽  
Quasi Equilibrium ◽  
Mass Relation ◽  
Disc Galaxy

ABSTRACT In recent years, simple models of galaxy formation have been shown to provide reasonably good matches to available data on high-redshift luminosity functions. However, these prescriptions are primarily phenomenological, with only crude connections to the physics of galaxy evolution. Here, we introduce a set of galaxy models that are based on a simple physical framework but incorporate more sophisticated models of feedback, star formation, and other processes. We apply these models to the high-redshift regime, showing that most of the generic predictions of the simplest models remain valid. In particular, the stellar mass–halo mass relation depends almost entirely on the physics of feedback (and is thus independent of the details of small-scale star formation) and the specific star formation rate is a simple multiple of the cosmological accretion rate. We also show that, in contrast, the galaxy’s gas mass is sensitive to the physics of star formation, although the inclusion of feedback-driven star formation laws significantly changes the naive expectations. While these models are far from detailed enough to describe every aspect of galaxy formation, they inform our understanding of galaxy formation by illustrating several generic aspects of that process, and they provide a physically grounded basis for extrapolating predictions to faint galaxies and high redshifts currently out of reach of observations. If observations show violations from these simple trends, they would indicate new physics occurring inside the earliest generations of galaxies.

scholarly journals Simulating the interstellar medium of galaxies with radiative transfer, non-equilibrium thermochemistry, and dust

2020 ◽  
Vol 499 (4) ◽  
pp. 5732-5748 ◽  
Author(s):  
Rahul Kannan ◽  
Federico Marinacci ◽  
Mark Vogelsberger ◽  
Laura V Sales ◽  
Paul Torrey ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Galaxy Formation ◽  
State Of The Art ◽  
Complex Function ◽  
Ionization State ◽  
Radiation Fields ◽  
Stellar Feedback ◽  
Wide Range ◽  
Dust Distribution ◽  
Non Equilibrium

ABSTRACT We present a novel framework to self-consistently model the effects of radiation fields, dust physics, and molecular chemistry (H2) in the interstellar medium (ISM) of galaxies. The model combines a state-of-the-art radiation hydrodynamics module with a H  and He  non-equilibrium thermochemistry module that accounts for H2 coupled to an empirical dust formation and destruction model, all integrated into the new stellar feedback framework SMUGGLE. We test this model on high-resolution isolated Milky-Way (MW) simulations. We show that the effect of radiation feedback on galactic star formation rates is quite modest in low gas surface density galaxies like the MW. The multiphase structure of the ISM, however, is highly dependent on the strength of the interstellar radiation field. We are also able to predict the distribution of H2, that allow us to match the molecular Kennicutt–Schmidt (KS) relation, without calibrating for it. We show that the dust distribution is a complex function of density, temperature, and ionization state of the gas. Our model is also able to match the observed dust temperature distribution in the ISM. Our state-of-the-art model is well-suited for performing next-generation cosmological galaxy formation simulations, which will be able to predict a wide range of resolved (∼10 pc) properties of galaxies.

scholarly journals New methods for identifying Lyman continuum leakers and reionization-epoch analogues

2020 ◽  
Vol 498 (1) ◽  
pp. 164-180 ◽  
Author(s):  
Harley Katz ◽  
Dominika Ďurovčíková ◽  
Taysun Kimm ◽  
Joki Rosdahl ◽  
Jeremy Blaizot ◽  
...  
Keyword(s):  
Emission Line ◽  
Galaxy Formation ◽  
Dwarf Galaxy ◽  
High Redshift ◽  
Indirect Methods ◽  
High Redshift Galaxies ◽  
Lyman Continuum ◽  
The Universe ◽  
Ionization Parameter ◽  
Redshift Galaxies

ABSTRACT Identifying low-redshift galaxies that emit Lyman continuum radiation (LyC leakers) is one of the primary, indirect methods of studying galaxy formation in the epoch of reionization. However, not only has it proved challenging to identify such systems, it also remains uncertain whether the low-redshift LyC leakers are truly ‘analogues’ of the sources that reionized the Universe. Here, we use high-resolution cosmological radiation hydrodynamics simulations to examine whether simulated galaxies in the epoch of reionization share similar emission line properties to observed LyC leakers at z ∼ 3 and z ∼ 0. We find that the simulated galaxies with high LyC escape fractions (fesc) often exhibit high O32 and populate the same regions of the R23–O32 plane as z ∼ 3 LyC leakers. However, we show that viewing angle, metallicity, and ionization parameter can all impact where a galaxy resides on the O32–fesc plane. Based on emission line diagnostics and how they correlate with fesc, lower metallicity LyC leakers at z ∼ 3 appear to be good analogues of reionization-era galaxies. In contrast, local [S ii]-deficient galaxies do not overlap with the simulated high-redshift LyC leakers on the S ii Baldwin–Phillips–Terlevich (BPT) diagram; however, this diagnostic may still be useful for identifying leakers. We use our simulated galaxies to develop multiple new diagnostics to identify LyC leakers using infrared and nebular emission lines. We show that our model using only [C ii]158 μm and [O iii]88 μm can identify potential leakers from non-leakers from the local Dwarf Galaxy Survey. Finally, we apply this diagnostic to known high-redshift galaxies and find that MACS 1149_JD1 at z = 9.1 is the most likely galaxy to be actively contributing to the reionization of the Universe.

scholarly journals Theoretically modelling photoionised regions with fractal geometry in three-dimension

2019 ◽  
Vol 15 (S352) ◽  
pp. 71-72
Author(s):  
Yifei Jin ◽  
Lisa Kewley ◽  
Ralph Sutherland
Keyword(s):  
Monte Carlo ◽  
Emission Line ◽  
Galaxy Formation ◽  
Fractal Geometry ◽  
Complex Geometry ◽  
High Redshift ◽  
Three Dimension ◽  
High Redshift Galaxies ◽  
Monte Carlo Techniques ◽  
Galaxy Formation And Evolution

AbstractAccurate predictions of the physics of interstellar medium (ISM) are vital for understanding galaxy formation and evolution. Modelling photoionized regions with complex geometry produces realistic ionization structures within the nebulae, providing the necessary physical predictions to interpret observational data. 3D photoionization codes built with Monte Carlo techniques provide powerful tools to produce the ionizing radiation field with fractal geometry. We present a high-resolution Monte Carlo modelling of a nebula with fractal geometry, and will further show how nebular geometry influences the emission-line behaviours. Our research has important implications for studies of emission-line ratios in high redshift galaxies.

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