Models Of Star Formation Research Articles

Redshift-dependent galaxy formation efficiency at z = 5 − 13 in the FirstLight Simulations

Context. Some models of the formation of first galaxies predict low masses and faint objects at extremely high redshifts, z ≃ 9 − 15. However, the first observations of this epoch indicate a higher-than-expected number of bright (sometimes massive) galaxies. Aims. Numerical simulations can help to elucidate the mild evolution of the bright end of the UV luminosity function and they can provide the link between the evolution of bright galaxies and variations of the galaxy formation efficiency across different redshifts. Methods. We use the FirstLight database of 377 zoom-in cosmological simulations of a volume- and mass-complete sample of galaxies. Mock luminosities are estimated by a dust model constrained by observations of the β–MUV relation at z = 6 − 9. Results. FirstLight contains a high number of bright galaxies, MUV ≤ −20, consistent with current data at z = 6 − 13. The evolution of the UV cosmic density is driven by the evolution of the galaxy efficiency and the relation between MUV and halo mass. The efficiency of galaxy formation increases significantly with mass and redshift. At a fixed mass, galactic halos at extremely high redshifts convert gas into stars at a higher rate than at lower redshifts. The high gas densities in these galaxies enable high efficiencies. Our simulations predict higher number densities of massive galaxies, M* ≃ 109 M⊙, than other models with constant efficiency. Conclusions. Cosmological simulations of galaxy formation with detailed models of star formation and feedback can reproduce the different regimes of galaxy formation across cosmic history.

Extreme-value modelling of the brightest galaxies at z ≳ 9

Abstract Data from the James Webb Space Telescope have revealed an intriguing population of bright galaxies at high redshifts. In this work, we use extreme-value statistics to calculate the distribution (in UV magnitude) of the brightest galaxies in the redshift range 9 ≲ z ≲ 16. We combine the Generalised Extreme Value (GEV) approach with modelling of the galaxy luminosity function. We obtain predictions of the brightest galaxies for a suite of luminosity functions, including the Schechter and double power law functions, as well as a model parametrised by the stellar formation efficiency f*. We find that the JWST data is broadly consistent with f* of $5~{{\ \rm per\ cent}}-10~{{\ \rm per\ cent}}$, and that the brightest galaxy at z ∼ 16 will have $M_{\rm UV}\approx -23.5^{0.8}_{0.4}$. If f* is dependent on halo mass, we predict $M_{\rm UV}\approx -22.5^{0.5}_{1.5}$ for such an object. We show that extreme-value statistics not only predicts the magnitude of the brightest galaxies at high redshifts, but may also be able to distinguish between models of star formation in high-redshift galaxies.

Dead or Alive? How Bursty Star Formation and Patchy Dust Can Cause Temporary Quiescence in High-redshift Galaxies

The recent discovery of a galaxy at z = 7.3 with undetected optical emission lines and a blue UV-to-optical continuum ratio in JWST spectroscopy is surprising and needs to be explained physically. Here, we explore two possibilities that could cause such a seemingly quiescent ∼5 × 108 M ⊙ galaxy in the early Universe: (i) stochastic variations in the star formation history (SFH) and (ii) the effect of spatially varying dust attenuation on the measured line and continuum emission properties. Both scenarios can play out at the same time to amplify the effect. A stochastic star formation model (similar to realistic SFHs from hydrodynamical simulations of similar-mass galaxies) can create such observed properties if star formation is fast-varying with a correlation time of <150 Myr given a reasonable burst amplitude of ∼0.6 dex. The total time spent in this state is less than 20 Myr, and the likelihood of such a state to occur over 500 Myr at z = 7 is ∼50% (consistent with current observations). On the other hand, we show that a spectrum with blue UV continuum and lack of emission lines can be reproduced by a blue+red composite spectrum. The UV continuum is emitted from dust-free density-bounded H ii regions (blue component), while the red component is a dust-obscured starburst with weakened emission lines due to strong differential dust attenuation between stellar and nebular emission. Future resolving far-infrared observations with the Atacama Large Millimeter/submillimeter Array will shed light on the latter scenario.

Chemo-dynamical Evolution of Simulated Satellites for a Milky Way–like Galaxy

The chemical abundances of Milky Way’s (MW's) satellites reflect their star formation histories (SFHs), yet, due to the difficulty of determining the ages of old stars, the SFHs of most satellites are poorly measured. Ongoing and upcoming surveys will obtain around 10 times more medium-resolution spectra for stars in satellites than are currently available. To correctly extract SFHs from large samples of chemical abundances, the relationship between chemical abundances and SFHs needs to be clarified. Here, we perform a high-resolution cosmological zoom-in simulation of a MW-like galaxy with detailed models of star formation, supernova (SN) feedback, and metal diffusion. We quantify SFHs, metallicity distribution functions, and the α-element (Mg, Ca, and Si) abundances in satellites of the host galaxy. We find that star formation in most simulated satellites is quenched before infalling to their host. Star formation episodes in simulated satellites are separated by a few hundred Myr owing to SN feedback; each star formation event produces groups of stars with similar [α/Fe] and [Fe/H]. We then perform a mock observation of the upcoming Subaru Prime Focus Spectrograph (PFS) observations. We find that Subaru PFS will be able to detect distinct groups of stars in [α/Fe] versus [Fe/H] space, produced by episodic star formation. This result means that episodic SFHs can be estimated from the chemical abundances of ≳1000 stars determined with medium-resolution spectroscopy.

Tests of subgrid models for star formation using simulations of isolated disc galaxies

ABSTRACT We use smoothed particle hydrodynamics simulations of isolated Milky Way-mass disc galaxies that include cold, interstellar gas to test subgrid prescriptions for star formation (SF). Our fiducial model combines a Schmidt law with a gravitational instability criterion, but we also test density thresholds and temperature ceilings. While SF histories are insensitive to the prescription for SF, the Kennicutt–Schmidt (KS) relations between SF rate and gas surface density can discriminate between models. We show that our fiducial model, with an SF efficiency per free-fall time of 1 per cent, agrees with spatially resolved and azimuthally averaged observed KS relations for neutral, atomic, and molecular gas. Density thresholds do not perform as well. While temperature ceilings selecting cold, molecular gas can match the data for galaxies with solar metallicity, they are unsuitable for very low-metallicity gas and hence for cosmological simulations. We argue that SF criteria should be applied at the resolution limit rather than at a fixed physical scale, which means that we should aim for numerical convergence of observables rather than of the properties of gas labelled as star-forming. Our fiducial model yields good convergence when the mass resolution is varied by nearly 4 orders of magnitude, with the exception of the spatially resolved molecular KS relation at low surface densities. For the gravitational instability criterion, we quantify the impact on the KS relations of gravitational softening, the SF efficiency, and the strength of supernova feedback, as well as of observable parameters such as the inclusion of ionized gas, the averaging scale, and the metallicity.

Effects of feedback-free starburst galaxies on the 21-cm signal and reionization history

ABSTRACT Different star formation models at Cosmic Dawn produce detectable signatures in the observables of upcoming 21-cm experiments. In this work, we consider the physical scenario of feedback-free starbursts (FFB), according to which the star formation efficiency (SFE) is enhanced in sufficiently massive haloes at early enough times, thus explaining the indication from the JWST for an excess of bright galaxies at $z \ge 10$. We model the contribution of FFBs to popII SFE and compute the impact these have on the 21-cm global signal and power spectrum. We show that FFBs affect the evolution of the brightness temperature and the 21-cm power spectrum, but they only have a limited effect on the neutral hydrogen fraction. We investigate how the observables are affected by changes in the underlying star formation model and by contribution from popIII stars. Finally, we forecast the capability of next-generation Hydrogen Epoch of Reionization Array (HERA) to detect the existence of FFB galaxies via power spectrum measurements. Our results show the possibility of a significant detection, provided that popII stars are the main drivers of lowering the spin temperature. Efficient popIII star formation will make the detection more challenging.

H i discs of L* galaxies as probes of the baryonic physics of galaxy evolution

ABSTRACT Understanding what shapes the cold gas component of galaxies, which both provides the fuel for star formation and is strongly affected by the subsequent stellar feedback, is a crucial step towards a better understanding of galaxy evolution. Here, we analyse the H i properties of a sample of 46 Milky Way halo-mass galaxies, drawn from cosmological simulations (EMP-Pathfinder and Firebox). This set of simulations comprises galaxies evolved self-consistently across cosmic time with different baryonic sub-grid physics: three different star formation models [constant star formation efficiency (SFE) with different star formation eligibility criteria, and an environmentally dependent, turbulence-based SFE] and two different feedback prescriptions, where only one sub-sample includes early stellar feedback. We use these simulations to assess the impact of different baryonic physics on the H i content of galaxies. We find that the galaxy-wide H i properties agree with each other and with observations. However, differences appear for small-scale properties. The thin H i discs observed in the local universe are only reproduced with a turbulence-dependent SFE and/or early stellar feedback. Furthermore, we find that the morphology of H i discs is particularly sensitive to the different physics models: galaxies simulated with a turbulence-based SFE have discs that are smoother and more rotationally symmetric, compared to those simulated with a constant SFE; galaxies simulated with early stellar feedback have more regular discs than supernova-feedback-only galaxies. We find that the rotational asymmetry of the H i discs depends most strongly on the underlying physics model, making this a promising observable for understanding the physics responsible for shaping the interstellar medium of galaxies.

Modeling Molecular Hydrogen in Low-metallicity Galaxies

We use a suite of hydrodynamics simulations of the interstellar medium (ISM) within a galactic disk, which includes radiative transfer, a nonequilibrium model of molecular hydrogen, and a realistic model for star formation and feedback, to study the structure of the ISM and H2 abundance as a function of local ISM properties. We show that the star formation rate and structure of the ISM are sensitive to the metallicity of the gas with a progressively smoother density distribution with decreasing metallicity. In addition to the well-known trend of the H I–H 2 transition shifting to higher densities with decreasing metallicity, the maximum achieved molecular fraction in the ISM drops drastically at Z ≲ 0.2 Z ⊙ as the formation time of H2 becomes much longer than a typical lifetime of dense regions of the ISM. We present accurate fitting formulae for both volumetric and projected fH2 measured on different scales as a function of gas metallicity, UV radiation field, and gas density. We show that when the formulae are applied to the patches in the simulated galaxy, the overall molecular gas mass is reproduced to better than a factor of ≲1.5 across the entire range of metallicities and scales. We also show that the presented fit is considerably more accurate than any of the previous fH2 models and fitting formulae in the low-metallicity regime. The fit can thus be used for modeling molecular gas in low-resolution simulations and semi-analytic models of galaxy formation in the dwarf and high-redshift regimes.

Disk Wind Feedback from High-mass Protostars. III. Synthetic CO Line Emission

Abstract To test theoretical models of massive star formation it is important to compare their predictions with observed systems. To this end, we conduct CO molecular line radiative transfer post-processing of 3D magnetohydrodynamic simulations of various stages in the evolutionary sequence of a massive protostellar core, including its infall envelope and disk wind outflow. Synthetic position–position–velocity cubes of various transitions of 12CO, 13CO, and C18O emission are generated. We also carry out simulated Atacama Large Millimeter/submillimeter Array (ALMA) observations of this emission. We compare the mass, momentum, and kinetic energy estimates obtained from molecular lines to the true values, finding that the mass and momentum estimates can have uncertainties of up to a factor of 4. However, the kinetic energy estimated from molecular lines is more significantly underestimated. Additionally, we compare the mass outflow rate and momentum outflow rate obtained from the synthetic spectra with the true values. Finally, we compare the synthetic spectra with real examples of ALMA-observed protostars and determine the best-fitting protostellar masses and outflow inclination angles. We then calculate the mass outflow rate and momentum outflow rate for these sources, finding that both rates agree with theoretical protostellar evolutionary tracks.

Implication of the Velocity Dispersion Scalings on High-mass Star Formation in Molecular Clouds

This paper is aimed at exploring the implications of velocity-dispersion scalings on high-mass star formation in molecular clouds, including the scalings of Larson’s linewidth–size (σ– R) and ratio–mass surface density ( L – Σ; here L = σ/R 0.5). We have systematically analyzed the σ parameter of well-selected 221 massive clumps, complemented with published samples of other hierarchical density structures of molecular clouds over spatial scales of 0.01–10 pc. Those massive clumps are classified into four phases: quiescent, protostellar, H ii region, and PDR clumps in an evolutionary sequence. The velocity dispersion of clumps increases overall with the evolutionary sequence, reflecting enhanced stellar feedback in more evolved phases. The relations of σ– R and L – Σ are weak with the clump sample alone, but become evident when combined with others spanning a much wider spatial scales. For σ– R, its tight relation indicates a kinematic connection between hierarchical density structures, supporting theoretical models of multiscale high-mass star formation. From the L – Σ relation, cloud structures can be found to transition from overvirial state (α vir > 2) to subvirial state (α vir < 2) as they become smaller and denser, indicating a possible shift in the governing force from turbulence to gravity. This implies that the multiscale physical process of high-mass star formation hinges on the self-gravity of subvirial molecular clouds. However, the influence of turbulence may not be dismissed until large-scale clouds attain a subvirial state. This is pending confirmation from future multiscale kinematic observations of molecular clouds with uniform observing settings.

Signatures of magnetic braking in Class 0 protostars: Exploring the gas kinematics in magnetized models of low-mass star formation

Signatures of magnetic braking in Class 0 protostars: Exploring the gas kinematics in magnetized models of low-mass star formation

Radiation transport methods in star formation simulations

Radiation transport plays a crucial role in star formation models, as certain questions within this field cannot be accurately addressed without taking it into account. Given the high complexity of the interstellar medium from which stars form, numerical simulations are frequently employed to model the star formation process. This study reviews recent methods for incorporating radiation transport into star formation simulations, discussing them in terms of the used algorithms, treatment of radiation frequency dependence, the interaction of radiation with the gas, and the parallelization of methods for deployment on supercomputers. Broadly, the algorithms fall into two categories: i) moment-based methods, encompassing the flux-limited diffusion approximation, M1 closure, and variable Eddington tensor methods, and ii) methods directly solving the radiation transport equation, including forward and reverse ray tracing, characteristics-based methods, and Monte Carlo techniques. Beyond discussing advantages and disadvantages of these methods, the review also lists recent radiation hydrodynamic codes implemented the described methods.

To be, or not to be: Balmer breaks in high-z galaxies with JWST

ABSTRACT Standard models of structure formation allow us to predict the cosmic timescales relevant for the onset of star formation and the assembly history of galaxies at high redshifts (z &amp;gt; 10). The strength of the Balmer break represents a well-known diagnostic of the age and star formation history of galaxies, which enables us to compare observations with contemporary simulations – thus shedding light on the predictive power of our current models of star formation in the early Universe. Here, we measure the Balmer break strength for 23 spectroscopically confirmed galaxies at redshifts 6 ≲ z ≲ 12 using public JWST NIRSpec data from the cycle 1 GO 1433 and GO 2282 programmes (PI Coe), as well as public spectroscopic data from the JWST Deep Extragalactic Survey (JADES). We find that the range of observed Balmer break strengths agree well with that of current simulations given our measurement uncertainties. No cases of anomalously strong Balmer breaks are detected, and therefore no severe departures from the predictions of contemporary models of star formation. However, there are indications of a number of outliers in the observed distribution which have weaker Balmer breaks than predicted by simulations.

Emergence and cosmic evolution of the Kennicutt–Schmidt relation driven by interstellar turbulence

The scaling relations between the gas content and star formation rate of galaxies provide useful insights into the processes governing their formation and evolution. We investigated the emergence and the physical drivers of the global Kennicutt–Schmidt (KS) relation at 0.25 ≤ z ≤ 4 in the cosmological hydrodynamic simulation NEWHORIZON, capturing the evolution of a few hundred galaxies with a resolution down to 34 pc. The details of this relation vary strongly with the stellar mass of galaxies and the redshift. A power-law relation ΣSFR ∝ Σgasa with a ≈ 1.4, like that found empirically, emerges at z ≈ 2 − 3 for the more massive half of the galaxy population. However, no such convergence is found in the lower-mass galaxies, for which the relation gets shallower with decreasing redshift. At galactic scales, the star formation activity correlates with the level of turbulence of the interstellar medium, quantified by the Mach number, rather than with the gas fraction (neutral or molecular), confirming the conclusions found in previous works. With decreasing redshift, the number of outliers with short depletion times diminishes, reducing the scatter of the KS relation, while the overall population of galaxies shifts toward low densities. Our results, from parsec-scale star formation models calibrated with local Universe physics, demonstrate that the cosmological evolution of the environmental (e.g., mergers) and internal conditions (e.g., gas fractions) conspire to shape the KS relation. This is an illustration of how the interplay of global and local processes leaves a detectable imprint on galactic-scale observables and scaling relations.

Star Formation in the H ii Region Sh2-87: Evidence of Global Hierarchical Collapse

We present a detailed study of the Sh2-87 H ii region using a multiwavelength data set in optical to radio bands. A Herschel column density map revealed that the host cloud is filamentary in nature, and together they formed a central dense hub. The extinction map generated using near-infrared photometric data also signifies the nonuniform distribution of the cloud and reveals its filamentary nature. We estimated a sizable variable extinction over the region up to A V = 34.4 mag, with an average value of A V = 3.4 mag. Using the various infrared color–color criteria, we identified 13 Class I and 202 Class II young stellar objects (YSOs) and 22 Hα-emitting sources toward this region. Further analysis showed that the cluster is mainly composed of low-mass YSOs with a typical age of ∼3 Myr having masses in the range of 0.1–6.0 M ⊙. The identified evolved YSOs (i.e., Class II YSOs) are primarily distributed along the filaments and in the outer parts of the cloud, while the recent star formation, inferred by the presence of Class I YSOs, ionized gas, and star-forming clumps, is observed in the hub region. The overall star formation scenario in the Sh2-87 region resembles the global hierarchical collapse model of star formation, where younger massive star formation activity is expected at the central hub along with the distribution of evolved low-mass YSOs in the filaments and the outer parts of the cloud.

Cloud–cloud collisions triggering star formation in galaxy simulations

ABSTRACT Cloud–cloud collisions (CCCs) are expected to compress gas and trigger star formation. However, it is not well understood how the collisions and the induced star formation affect galactic-scale properties. By developing an on-the-fly algorithm to identify CCCs at each time-step in a galaxy simulation and a model that relates CCC-triggered star formation to collision speeds, we perform simulations of isolated galaxies to study the evolution of galaxies and giant molecular clouds (GMCs) with prescriptions of self-consistent CCC-driven star formation and stellar feedback. We find that the simulation with the CCC-triggered star formation produces slightly higher star formation rates and a steeper Kennicutt–Schmidt relation than that with a more standard star formation recipe, although collision speeds and frequencies are insensitive to the star formation models. In the simulation with the CCC model, about $70{{\ \rm per\ cent}}$ of the stars are born via CCCs, and colliding GMCs with masses of $\approx 10^{5.5}\, \mbox{$\rm M_{\odot}$}$ are the main drivers of CCC-driven star formation. In the simulation with the standard star formation recipe, about 50 per cent of stars are born in colliding GMCs even without the CCC-triggered star formation model. These results suggest that CCCs may be one of the most important star formation processes in galaxy evolution. Furthermore, we find that a post-processing analysis of CCCs, as used in previous studies in galaxy simulations, may lead to slightly greater collision speeds and significantly lower collision frequencies than the on-the-fly analysis.

The ALMaQUEST Survey XI: a strong but non-linear relationship between star formation and dynamical equilibrium pressure

ABSTRACT We present the extended ALMA MaNGA QUEnching and STar formation survey (ALMaQUEST), a combination of the original 46 ALMaQUEST galaxies plus new ALMA observations for a further 20 interacting galaxies. Three well-studied scaling relations are fit to the 19 999 star-forming spaxels in the extended sample, namely the resolved Schmidt–Kennicutt relation, the resolved star-forming main-sequence and the resolved molecular gas main sequence. We additionally investigate the relationship between the dynamical equilibrium pressure (PDE) and star formation rate surface density (ΣSFR), which we refer to as the resolved PDE (rPDE) relation. Contrary to previous studies that have focussed on normal star-forming galaxies and found an approximately linear rPDE relation, the presence of more vigourously star-forming galaxies in the extended ALMaQUEST sample reveals a marked turnover in the relation at high pressures. Although the scatter around the linear fit to the rPDE relation is similar to the other three relations, a random forest analysis, which can extract non-linear dependences, finds that PDEis unambiguously more important than either $\Sigma _{\rm H_2}$ or Σ⋆ for predicting ΣSFR. We compare the observed rPDE relation to the prediction of the pressure-regulated feedback-modulated (PRFM) model of star formation, finding that galaxies residing on the global SFMS do indeed closely follow the rPDE relation predicted by the PRFM theory. However, galaxies above and below the global SFMS show significant deviations from the model. Galaxies with high SFR are instead consistent with models that include other contributions to turbulence in addition to the local star formation feedback.

Probing star formation in five of the most massive spiral galaxies observed through ASTROSAT UltraViolet Imaging Telescope

ABSTRACT We present highly resolved and sensitive imaging of the five nearby massive spiral galaxies (with rotation velocities $\rm \gt 300\, km\, s^{-1}$) observed by the UltraViolet Imaging Telescope onboard India’s multiwavelength astronomy satellite ASTROSAT, along with other archival observations. These massive spirals show a far-ultraviolet star formation rate in the range of ∼ 1.4 – 13.7 ${\rm M}_{\odot } \, \mathrm{yr}^{-1}$ and fall in the ‘Green Valley’ region with a specific star formation rate within ∼ 10−11.5 – 10−10.5 yr−1. Moreover, the mean star formation rate density of the highly resolved star-forming clumps of these objects is in the range 0.011 – 0.098 ${\rm M}_{\odot }\, \mathrm{ yr}^{-1}\, \mathrm{kpc}^{-2}$, signifying localized star formation. From the spectral energy distributions, under the assumption of a delayed star formation model, we show that the star formation of these objects had peaked in the period of ∼ 0.8 – 2.8 Gyr after the ‘Big Bang’ and the object that has experienced the peak sooner after the ‘Big Bang’ show relatively less star-forming activity at z ∼ 0 and falls below the main-sequence relation for a stellar content of $\rm \gtrsim 10^{11} \, {\rm M}_{\odot }$. We also show that these objects accumulated much of their stellar mass in the early period of evolution with ∼ 31 – 42 per cent of the total stellar mass obtained in a time of (1/16) – (1/5)th the age of the Universe. We estimate that these massive objects convert their halo baryons into stars with efficiencies falling between ∼ 7 and 31 per cent.

A new star formation recipe for magnetohydrodynamics simulations of galaxy formation

ABSTRACT Star formation has been observed to occur at globally low yet locally varying efficiencies. As such, accurate capture of star formation in numerical simulations requires mechanisms that can replicate both its smaller scale variations and larger scale properties. Magnetic fields are thought to play an essential role within the turbulent interstellar medium (ISM) and affect molecular cloud collapse. However, it remains to be fully explored how a magnetized model of star formation might influence galaxy evolution. We present a new model for a sub-grid star formation recipe that depends on the magnetic field. We run isolated disc galaxy simulations to assess its impact on the regulation of star formation using the code ramses. Building upon existing numerical methods, our model derives the star formation efficiency from local properties of the sub-grid magnetized ISM turbulence, assuming a constant Alfvén speed at sub-parsec scales. Compared to its non-magnetized counterpart, our star formation model suppresses the initial starburst by a factor of 2 while regulating star formation later on to a nearly constant rate of ∼1 M⊙ yr−1. Differences also arise in the local Schmidt law with a shallower power-law index for the magnetized star formation model. Our results encourage further examination into the notion that magnetic fields are likely to play a non-trivial role in our understanding of star and galaxy formation.

LIMpy: A Semianalytic Approach to Simulating Multiline Intensity Maps at Millimeter Wavelengths

Mapping of multiple lines such as the fine-structure emission from [C ii] (157.7 μm), [O iii] (52 and 88.4 μm), and rotational emission lines from CO are of particular interest for upcoming line intensity mapping (LIM) experiments at millimeter wavelengths, due to their brightness features. Several upcoming experiments aim to cover a broad range of scientific goals, from detecting signatures of the epoch of reionization to the physics of star formation and its role in galaxy evolution. In this paper, we develop a semianalytic approach to modeling line strengths as functions of the star formation rate (SFR) or infrared luminosity based on observations of local and high-z galaxies. This package, LIMpy (Line Intensity Mapping in Python), estimates the intensity and power spectra of [C ii], [O iii], and CO rotational transition lines up to the J levels (1–0) to (13–12) based both on analytic formalism and on simulations. We develop a relation among halo mass, SFR, and multiline intensities that permits us to construct a generic formula for the evolution of several line strengths up to z ∼ 10. We implement a variety of star formation models and multiline luminosity relations to estimate the astrophysical uncertainties on the intensity power spectrum of these lines. As a demonstration, we predict the signal-to-noise ratio of [C ii] detection for an EoR-Spec-like instrument on the Fred Young Submillimeter Telescope. Furthermore, the ability to use any halo catalog allows the LIMpy code to be easily integrated into existing simulation pipelines, providing a flexible tool to study intensity mapping in the context of complex galaxy formation physics.