From rest-frame luminosity functions to observer-frame colour distributions: tackling the next challenge in cosmological simulations

Bravo, Matías; Lagos, Claudia del P.; Robotham, Aaron S. G.; Bellstedt, Sabine; Obreschkow, Danail

doi:10.1093/mnras/staa2027

Cited by 20 publications

(14 citation statements)

References 93 publications

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“…We are now able to simulate the physics of galaxy formation and, to some extent, link galaxy properties to the host halo properties. For example, the UNIVERSEMACHINE (Behroozi et al 2019) that reasonably parametrizes the galaxy growth-halo assembly correlation and the SHARK (Lagos et al 2018) that agrees fairly well with observations (Bravo et al 2020). But there is still a need for improvement in understanding the process of galaxy formation (see Naab & Ostriker 2017, for a review).…”

Section: Introductionmentioning

confidence: 71%

Galaxy and Mass Assembly (GAMA)

Sureshkumar

Durkalec

Pollo

et al. 2021

A&A

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Context. Galaxies are biased tracers of the underlying network of dark matter. The strength of this bias depends on various galaxy properties, as well as on redshift. One of the methods used to study these dependences of the bias are measurements of galaxy clustering. Such studies are made using galaxy samples from various catalogues -frequently bearing their own problems related to sample selection methods. It is therefore crucial to understand how sample choice influences the clustering measurements, and which galaxy property is the most direct tracer of the galaxy environment. Aims. We investigate how different galaxy properties -luminosities in u, g, r, J, K-bands, stellar mass, star formation rate and specific star formation rate trace the environment in the local universe. We also study the effect of survey flux limits on galaxy clustering measurements. Methods. We measure the two-point correlation function (2pCF) and marked correlation functions (MCFs) using the aforementioned properties as marks. We use nearly stellar-mass-complete galaxy sample in the redshift range 0.1 < z < 0.16 from the Galaxy And Mass Assembly (GAMA) survey with a flux limit of r < 19.8. Further, we impose a brighter flux limit of r < 17.8 to our sample and repeat the measurements to study how this affects galaxy clustering analysis. We compare our results to measurements from the Sloan Digital Sky Survey (SDSS) with flux limits of r < 17.8 and r < 16.8. Results. We show that the stellar mass is the most direct tracer of galaxy environment, the K-band luminosity being a good substitute, although such a proxy sample misses close pairs of evolved, red galaxies. We also show that the u-band luminosity can be a proxy of star formation rate in the context of galaxy clustering. We observe an effect of the survey flux limit on clustering studies -samples with a higher flux limit (smaller magnitude) miss some information about close pairs of starburst galaxies.

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Section: Introductionmentioning

confidence: 71%

Galaxy and Mass Assembly (GAMA)

Sureshkumar

Durkalec

Pollo

et al. 2021

A&A

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“…1), we intentionally crosscontaminate the two populations in TNG100. Bravo et al (2020) have shown that assuming a fractional contamination between centrals and satellites closely mimics the procedure of running a group catalogue in a simulated galaxy lightcone and assessing contamination there. In a similar vein, we use weights when calculating statistical quantities (means, medians, and other percentiles) for TNG100 satellites or centrals, which are assigned to ensure we get back a desired effective purity.…”

Section: Cross-contamination Of Centrals and Satellitesmentioning

confidence: 92%

Molecular hydrogen in IllustrisTNG galaxies: carefully comparing signatures of environment with local CO and SFR data

Stevens

Lagos

Cortese

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We examine how the post-processed content of molecular hydrogen (H2) in galaxies from the TNG100 cosmological, hydrodynamic simulation changes with environment at z = 0, assessing central/satellite status and host halo mass. We make close comparisons with the carbon monoxide (CO) emission survey xCOLD GASS where possible, having mock-observed TNG100 galaxies to match the survey’s specifications. For a representative sample of host haloes across 1011 ≲ M200c/M⊙ < 1014.6, TNG100 predicts that satellites with m* ≥ 109 M⊙ should have a median deficit in their H2fractions of ∼0.6 dex relative to centrals of the same stellar mass. Once observational and group-finding uncertainties are accounted for, the signature of this deficit decreases to ∼0.2 dex. Remarkably, we calculate a deficit in xCOLD GASS satellites’ H2content relative to centrals of 0.2–0.3 dex, in line with our prediction. We further show that TNG100 and SDSS data exhibit continuous declines in the average star formation rates of galaxies at fixed stellar mass in denser environments, in quantitative agreement with each other. By tracking satellites from their moment of infall in TNG100, we directly show that atomic hydrogen (H i) is depleted at fractionally higher rates than H2on average. Supporting this picture, we find that the H2/H i mass ratios of satellites are elevated relative to centrals in xCOLD GASS. We provide additional predictions for the effect of environment on H2 — both absolute and relative to H i — that can be tested with spectral stacking in future CO surveys.

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“…In this work, we use the semi-analytic model (SAM) (L18), which has been shown to reproduce a wide variety of observations (Amarantidis et al 2019;Davies et al 2019a;Lagos et al 2019Lagos et al , 2020Chauhan et al 2019Chauhan et al , 2020Chauhan et al , 2021Bravo et al 2020). Most critical for this work are the excellent predictions of observed number counts, luminosity functions (Lagos et al 2019(Lagos et al , 2020 and low-redshift colour distributions (Bravo et al 2020). Briefly, a SAM generates and evolve galaxies using dark matter (DM) only N-body simulations, by following a set of equations that described the relevant physical processes to galaxy evolution.…”

Section: Simulated Catalogues ( )mentioning

confidence: 99%

“…We leave how to connect the central black hole properties in to the AGN SEDs in P S for future work. Following Lagos et al (2019); Bravo et al (2020), we use their parameterisation model for dust 5 , which uses the best-fit dust fraction-to-gas metallicity ratio from Rémy-Ruyer et al (2014) to calculate Σ dust , and then apply the Charlot & Fall (2000) parameters Σ dust -dependency found in Trayford et al (2020). For a more detailed description, we refer the reader to Sections 2.1 and 3.1 of Lagos et al (2019).…”

Section: Simulated Catalogues ( )mentioning

confidence: 99%

Forensic reconstruction of galaxy colour evolution and population characterisation

Bravo,

Robotham,

Lagos

et al. 2021

Preprint

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Mapping the evolution of galaxy colours, from blue star-forming to red passive systems, is fundamental to understand the processes involved in galaxy evolution. To this end, we reconstruct the colour evolution of low-redshift galaxies, combining stellar templates with star formation and metallicity histories of galaxies from the Galaxy And Mass Assembly survey and semi-analytic model. We use these colour histories to robustly characterise the evolution of red and blue galaxy populations over cosmic time. Using a Gaussian Mixture Model to characterise the colour distribution at any given epoch and stellar mass, we find both observations and simulations strongly favour a model with only two populations (blue and red), with no evidence for a third "green" population. We map the evolution of mean, weight, and scatter of the blue and red populations as a function of both stellar mass and lookback time. Using our simulated galaxy catalogue as a testbed, we find that we can accurately recover galaxies colour histories up to a lookback time of ∼ 6 Gyr. We find that both populations show little change in the mean colour for low-mass galaxies, while the colours at the massive end become significantly redder with time. The stellar mass above which the galaxy population is predominantly red decreases by 0.3 dex in the last 5 Gyrs. We find a good agreement between observations and simulations, with the largest tension being that massive galaxies from are too blue (a known issue with many galaxy evolution models).

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From rest-frame luminosity functions to observer-frame colour distributions: tackling the next challenge in cosmological simulations

Cited by 20 publications

References 93 publications

Galaxy and Mass Assembly (GAMA)

Galaxy and Mass Assembly (GAMA)

Molecular hydrogen in IllustrisTNG galaxies: carefully comparing signatures of environment with local CO and SFR data

Forensic reconstruction of galaxy colour evolution and population characterisation

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