Giacconi Fellowship from the Space Telescope Science Institute; NASA through a Hubble Fellowship grant from the Space Telescope Science Institute [HST-HF2-51353.001-A]; NASANational Aeronautics & Space Administration (NASA) [NAS5-26555]; NSFNational Science Foundation (NSF) [1066293]; National Science Foundation (NSF)National Science Foundation (NSF) [PHY11-25915]; Munich Institute for Astro-and Particle Physics (MIAPP) of the DFG cluster of excellence 'Origin and Structure of the Universe; Office of Science of the U.S. Department of EnergyUnited States Department of Energy (DOE) [DE-AC02-05CH11231]; DOEUnited States Department of Energy (DOE) [DE-AC02-76SF00515]; NASA High-EndComputing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center; PRACE [012060963]; Alfred P. Sloan FoundationAlfred P. Sloan Foundation; U.S. Department of Energy Office of ScienceUnited States Department of Energy (DOE); University of Arizona; Brazilian Participation Group; Brookhaven National LaboratoryUnited States Department of Energy (DOE); Carnegie Mellon University; French Participation Group; German Participation Group; Harvard University; Instituto de Astrofisica de Canarias; Michigan State/Notre Dame/JINA Participation Group; Johns Hopkins UniversityJohns Hopkins University; Lawrence Berkeley National LaboratoryUnited States Department of Energy (DOE); Max Planck Institute for Astrophysics; Max Planck Institute for Extraterrestrial Physics; Pennsylvania State University; Princeton UniversityPrinceton University; Spanish Participation Group; Yale University; University of FloridaUniversity of Florida; NewMexico State University; New York University; Ohio State UniversityOhio State University; University of Portsmouth; University of Tokyo; University of Utah; Vanderbilt University; University of Virginia; University of WashingtonUniversity of Washington

UniverseMachine: The Correlation between Galaxy Growth and Dark Matter Halo Assembly from z=0-10

The physics of diffuse gas accretion and the properties of the cold and hot modes of accretion on to proto-galaxies between z= 2 and 5.4 is investigated using the large cosmological simulation performed with the ramses code on the MareNostrum supercomputing facility. Galactic winds, chemical enrichment, ultraviolet background heating and radiative cooling are taken into account in this very high resolution simulation. Using accretion-weighted temperature histograms, we have performed two different measurements of the thermal state of the gas accreted towards the central galaxy.



The first measurement, performed using accretion-weighted histograms on a spherical surface of radius 0.2Rvir centred on the densest gas structure near the halo centre of mass, is a good indicator of the presence of an accretion shock in the vicinity of the galactic disc. We define the hot shock mass, Mshock, as the typical halo mass separating cold dominated from hot dominated accretion in the vicinity of the galaxy.



The second measurement is performed by radially averaging histograms between 0.2Rvir and Rvir, in order to detect radially extended structures such as gas filaments: this is a good proxy for detecting cold streams feeding the central galaxy. We define Mstream as the transition mass separating cold dominated from hot dominated accretion in the outer halo, marking the disappearance of these cold streams.



We find a hot shock transition mass of Mshock= 1011.6 M⊙ (dark matter), with no significant evolution with redshift. Conversely, we find that Mstream increases sharply with z. Our measurements are in agreement with the analytical predictions of Birnboim & Dekel and Dekel & Birnboim, if we correct their model by assuming low metallicity(≤10−3 Z⊙)for the filaments, correspondingly to our measurements. Metal enrichment of the intergalactic medium is therefore a key ingredient in determining the transition mass from cold to hot dominated diffuse gas accretion.



We find that the diffuse cold gas supply at the inner halo stops at z= 2 for objects with stellar masses of about 1011.1 M⊙, which is close to the quenching mass determined observationally by Bundy et al. However, its evolution with z is not well constrained, making it difficult to rule out or confirm the need for an additional feedback process such as active galactic nuclei.

Bimodal gas accretion in the HORIZON-MareNostrum galaxy formation simulation

Supermassive black hole feedback is thought to be responsible for the lack of star formation, or quiescence, in a significant fraction of galaxies. We explore how observable correlations between the specific star formation rate (sSFR), stellar mass (M$_{\rm{star}}$), and black hole mass (M$_{\rm{BH}}$) are sensitive to the physics of black hole feedback in a galaxy formation model. We use the IllustrisTNG simulation suite, specifically the TNG100 simulation and ten model variations that alter the parameters of the black hole model. Focusing on central galaxies at $z = 0$ with M$_{\rm{star}} > 10^{10}$ M$_{\odot}$, we find that the sSFR of galaxies in IllustrisTNG decreases once the energy from black hole kinetic winds at low accretion rates becomes larger than the gravitational binding energy of gas within the galaxy stellar radius. This occurs at a particular M$_{\rm{BH}}$ threshold above which galaxies are found to sharply transition from being mostly star-forming to mostly quiescent. As a result of this behavior, the fraction of quiescent galaxies as a function of M$_{\rm{star}}$ is sensitive to both the normalization of the M$_{\rm{BH}}$-M$_{\rm{star}}$ relation and the M$_{\rm{BH}}$ threshold for quiescence in IllustrisTNG. Finally, we compare these model results to observations of 91 central galaxies with dynamical M$_{\rm{BH}}$ measurements with the caveat that this sample is not representative of the whole galaxy population. While IllustrisTNG reproduces the observed trend that quiescent galaxies host more massive black holes, the observations exhibit a broader scatter in M$_{\rm{BH}}$ at a given M$_{\rm{star}}$ and show a smoother decline in sSFR with M$_{\rm{BH}}$.

The relationship between black hole mass and galaxy properties: Examining the black hole feedback model in IllustrisTNG

Fil: Cora, Sofia Alejandra. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - La Plata. Instituto de Astrofisica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronomicas y Geofisicas. Instituto de Astrofisica La Plata; Argentina

/pdf/semi-analytic-galaxies-i-synthesis-of-environmental-and-star-2z2hh61di2.pdf

Semi-analytic galaxies: I. Synthesis of environmental and star-forming regulation mechanisms

The internal properties of dark matter haloes correlate with the large-scale halo clustering strength at fixed halo mass – an effect known as assembly bias – and are also strongly affected by the local, non-linear cosmic web. Characterizing a halo’s local web environment by its tidal anisotropy α at scales approximately four times the halo radius, we demonstrate that these multiscale correlations represent two distinct statistical links: one between the internal property and α, and the other between α and large-scale (⁠|${\gtrsim}30\, h^{-1}\, {\rm Mpc}$|⁠) halo bias b_1. We focus on scalar internal properties of haloes related to formation time (concentration c_vir), shape (mass ellipsoid asphericity c/a), velocity dispersion structure (velocity ellipsoid asphericity /a_v and velocity anisotropy β), and angular momentum (dimensionless spin λ) in the mass range |$8\times 10^{11}\lesssim M_{\rm vir}/(\, h^{-1}\, \mathrm{M}_{\odot })\lesssim 5\times 10^{14}$|⁠. Using conditional correlation coefficients and other detailed tests, we show that the joint distribution of α, b_1, and any of the internal properties c ∈ {β, c_v/a_v, c/a, c_vir, λ} is consistent with p(α, b_1, c) ≃ p(α)p(b_1|α)p(c|α), at all but the largest masses. Thus, the assembly bias trends c↔b_1 reflect the two fundamental correlations c↔α and b_1↔α. Our results are unaffected by the exclusion of haloes with recent major merger events or splashback objects, although the latter are distinguished by the fact that α does not explain their assembly bias trends. The overarching importance of α provides a new perspective on the nature of assembly bias of distinct haloes, with potential ramifications for incorporating realistic assembly bias effects into mock catalogues of future large-scale structure surveys and for detecting galaxy assembly bias.

Cosmic web anisotropy is the primary indicator of halo assembly bias

We examine the quenched fraction of central and satellite galaxies as a function of galaxy stellar mass, halo mass, and the matter density of their large scale environment. Matter densities are inferred from our ELUCID simulation, a constrained simulation of local Universe sampled by SDSS, while halo masses and central/satellite classification are taken from the galaxy group catalog of Yang et al. The quenched fraction for the total population increases systematically with the three quantities. We find that the `environmental quenching efficiency', which quantifies the quenched fraction as function of halo mass, is independent of stellar mass. And this independence is the origin of the stellar mass-independence of density-based quenching efficiency, found in previous studies. Considering centrals and satellites separately, we find that the two populations follow similar correlations of quenching efficiency with halo mass and stellar mass, suggesting that they have experienced similar quenching processes in their host halo. We demonstrate that satellite quenching alone cannot account for the environmental quenching efficiency of the total galaxy population and the difference between the two populations found previously mainly arises from the fact that centrals and satellites of the same stellar mass reside, on average, in halos of different mass. After removing these halo-mass and stellar-mass effects, there remains a weak, but significant, residual dependence on environmental density, which is eliminated when halo assembly bias is taken into account. Our results therefore indicate that halo mass is the prime environmental parameter that regulates the quenching of both centrals and satellites.

http://iopscience.iop.org/article/10.3847/1538-4357/aa9e01/pdf

Guoliang Li

Papers

ELUCID. IV. Galaxy Quenching and its Relation to Halo Mass, Environment, and Assembly Bias

ELUCID IV: Galaxy Quenching and its Relation to Halo Mass, Environment, and Assembly Bias