We present the first results from new Bolshoi N-body cosmological LCDM simulation that uses parameters favored by current observations. The was done in a volume 250Mpc on side using 8billion particles with mass and force resolution adequate to follow subhalos down completeness limit of Vcirc=50km/ s circular velocity. Using excellent statistics halos (10M at every moment 50M over whole history) we accurate approximations for such as halo function, concentrations distinct subhalos, abundance...

It has long been regarded as difficult for a cosmological model to account simultaneously the galaxy luminosity, mass, and velocity distributions. We revisit this issue using modern compilation of observational data along with best available large-scale simulation dark matter. find that standard model, used in conjunction halo abundance matching (HAM) simple dynamical corrections, fits all basic statistics galaxies circular velocities Vcirc > 80 km/s. Our constraint is luminosity-velocity...

Globular clusters (GCs) formed when the Milky Way experienced a phase of rapid assembly. We use wealth information contained in Galactic GC population to quantify properties satellite galaxies from which assembled. To achieve this, we train an artificial neural network on E-MOSAICS cosmological simulations co-formation and co-evolution GCs their host galaxies. The uses ages, metallicities, orbital that same progenitor predict stellar masses accretion redshifts these progenitors. apply...

Any successful model of galaxy formation needs to explain the low rate star in small progenitors today's galaxies. This inefficiency is necessary for reproducing stellar-to-virial mass fractions, suggested by current abundance matching models. A possible driver this efficiency radiation pressure exerted ionizing photons from massive stars. The effect cosmological, zoom-in simulations modeled as a non-thermal that acts only dense and optically thick star-forming regions. We also include...

Abstract The ultra-diffuse galaxies DF2 and DF4 in the NGC 1052 group share several unusual properties: they both have large sizes 1 , rich populations of overluminous globular clusters 2–6 very low velocity dispersions that indicate little or no dark matter 7–10 . It has been suggested these were formed aftermath high-velocity collisions gas-rich 11–13 events resemble collision created bullet cluster 14 but on much smaller scales. gas separates from subsequent star formation leads to one...

Abstract It has been shown that ultra-diffuse galaxies (UDGs) have higher specific frequencies of globular clusters, on average, than other dwarf with similar luminosities. The UDG NGC 5846-UDG1 is among the most extreme examples cluster–rich found so far. Here we present new Hubble Space Telescope observations and analysis this galaxy its cluster system. We find hosts 54 ± 9 three to four times more any previously known a luminosity reported in previous studies. With L V ,gal ≈ 6 × 10 7 ⊙ (...

Dwarf spheroidal galaxies (dSphs) are extremely gas-poor, dark matter-dominated galaxies, which make them ideal to test the predictions of cold matter (CDM) model. We argue that removal baryonic component from gas-rich dwarf irregular progenitors dSphs, can substantially reduce their central density. Thus, it may play an important role in alleviating one problems CDM model related structure relatively massive satellite Milky Way (MW). Traditionally, collisionless cosmological N-body...

We present a detailed analysis of large-scale galactic outflow in the CGM massive (M_h ~ 10^12.5 Msun), star-forming (6.9 Msun/yr), sub-L* (0.5 L_B*) galaxy at z=0.39853 that exhibits wealth metal-line absorption spectra background quasar Q 0122-003 an impact parameter 163 kpc. The inclination angle (i=63 degree) and azimuthal (Phi=73 imply QSO sightline is passing through projected minor-axis galaxy. system shows multiphase, multicomponent structure with ultra-strong, wide velocity spread...

ABSTRACT The formation and evolution of stellar clusters is intimately linked to that their host galaxies. To study this connection, we present the emp-Pathfindersuite cosmological zoom-in Milky Way-mass simulations. These simulations contain a subgrid description for cluster evolution, allowing us simultaneous alongside galaxies across cosmic time. As key ingredient in these simulations, include physics multiphase nature interstellar medium (ISM), which enables studies how presence cold,...

ABSTRACT We present an end-to-end description of the formation globular clusters (GCs) combining a treatment for their and dynamical evolution within galaxy haloes with state-of-the-art semi-analytic simulation formation. Our approach allows us to obtain exquisite statistics study effect environment assembly history galaxies, while still allowing very efficient exploration parameter space. reference model, including both cluster disruption during mergers friction GCs galactic potential,...

Despite recent success in forming realistic present-day galaxies, simulations still form the bulk of their stars earlier than observations indicate. We investigate process stellar mass assembly low-mass field a dwarf and typical spiral, focusing on effects radiation from young clusters star formation (SF) histories. implement novel model SF with deterministic low efficiency per free-fall time, as observed molecular clouds. Stellar feedback is based star-forming regions, includes pressure...

In Churchill et al., we used halo abundance matching applied to 182 galaxies in the MgII Absorber-Galaxy Catalog (MAGIICAT, Nielsen al.) and showed that mean 2796 equivalent width follows a tight inverse-square power law, W_r(2796) ~ (D/R_vir)^-2, with projected location relative galaxy virial radius absorption covering fraction is invariant mass, M_h, over range 10.7 < M_h/M_solar 13.9. this work, explore multivariate relationships between W_r(2796), impact parameter, radius, theoretical...

The observed number of dwarf galaxies as a function rotation velocity is significantly smaller than predicted by the standard model cosmology. This discrepancy cannot be simply solved assuming strong baryonic feedback processes, since they would violate relation between maximum circular ($v_{\rm max}$) and baryon mass galaxies. A speculative but tantalising possibility that mismatch observation theory points towards existence non-cold or non-collisionless dark matter (DM). In this paper, we...

ABSTRACT Linking globular clusters (GCs) to the assembly of their host galaxies is an overarching goal in GC studies. The inference tight scaling relations between system properties and mass both stellar dark halo components are indicative intimate physical connection, yet have also raised fundamental questions about how when GCs form. Specifically, inferred correlation a (MGC) matter (Mhalo) galaxy has been posited as consequence causal relation formation mini-haloes during early epochs...

Globular clusters (GCs) are bright objects that span a wide range of galactocentric distances, and thus probes the structure dark matter (DM) haloes. In this work, we explore whether projected radial profiles GCs can be used to infer structural properties their host DM We use simulated GC populations in sample 166 central galaxies from $(34.4~\rm cMpc)^3$ periodic volume E-MOSAICS project. find more massive stellar with shallower density radially extended. addition, metal-poor subpopulations...

ABSTRACT Understanding what shapes the cold gas component of galaxies, which both provides fuel for star formation and is strongly affected by subsequent stellar feedback, a crucial step towards better understanding galaxy evolution. Here, we analyse H i properties sample 46 Milky Way halo-mass drawn from cosmological simulations (EMP-Pathfinder Firebox). This set comprises galaxies evolved self-consistently across cosmic time with different baryonic sub-grid physics: three models [constant...

We apply halo abundance matching to obtain galaxy virial masses, M h, and radii, Rvir, for 183 "isolated" galaxies from the "Mg ii Absorber-Galaxy Catalog." All have spectroscopic redshifts (0.07 ⩽ z 1.12) their circumgalactic medium (CGM) is probed in Mg absorption within projected galactocentric distances D 200 kpc. examine behavior of equivalent width, Wr(2796), covering fraction, fc, as a function D, D/Rvir, h. Bifurcating sample at median mass log h/M☉ = 12, we find (1) systematic...

The ages and metallicities of globular clusters (GCs) are known to be powerful tracers the properties their progenitor galaxies, enabling use in determining merger histories galaxies. However, while useful separating GCs into individual accretion events, orbits GC groups themselves have received less attention as probes galaxy properties. In this work, we simulations galaxies systems from E-MOSAICS project explore how present-day orbital related We find that deposited by events sensitive...

ABSTRACT We present a detailed comparison of the Milky Way (MW) globular cluster (GC) kinematics with 25 MW-mass cosmological simulations from E-MOSAICS project. While MW falls within kinematic distribution GCs spanned by simulations, relative its metal-rich ($[\rm {Fe}/\rm {H}] \gt -1.2$) versus metal-poor \lt and inner (r &amp;lt; 8 kpc) outer &amp;gt; populations are atypical for mass. To understand origins these features, we perform comprehensive statistical analysis find 18 correlations...

ABSTRACT The ultra-diffuse galaxy (UDG) NGC 1052-DF2 has a low dark matter content and hosts very unusual globular cluster (GC) population, with median luminosity ∼4 times higher than in most galaxies containing about 5 per cent of the galaxy’s stars. We apply theoretical model that predicts initial mass function as galactic environment to investigate origin DF2’s peculiar GC system. Using function, constrains star-forming conditions during formation its GCs, ∼9 Gyr ago. predict GCs formed...

ABSTRACT In addition to their low stellar densities, ultra-diffuse galaxies (UDGs) have a broad variety of dynamical mass-to-light ratios, ranging from dark matter (DM) dominated systems objects nearly devoid DM. To investigate the origin this diversity, we develop simple, semi-empirical model that predicts structural evolution galaxies, driven by feedback massive star clusters, as function departure mean SMHM relation. The galaxy located ≳ 0.5 dex above relation at Mhalo = 1010 M⊙ will host...

Globular clusters (GCs) are typically old, with most having formed at z >~ 2. This makes understanding their birth environments difficult, as they too distant to observe sufficient angular resolution resolve GC sites. Using 25 cosmological zoom-in simulations of Milky Way-like galaxies from the E-MOSAICS project, physically-motivated models for star formation, feedback, and evolution, disruption GCs, we identify present-day GCs. We find roughly half GCs in these in-situ (52.0 +/- 1.0 per...

It was recently proposed that the dark matter-deficient ultra-diffuse galaxies DF2 and DF4 in NGC1052 group could be products of a "bullet dwarf" collision between two gas-rich progenitor galaxies. In this model formed at same time immediate aftermath collision, strong prediction is their globular clusters should have nearly identical stellar populations. Here we test by measuring accurate F606W-F814W colors from deep HST/ACS imaging. We find are extremely homogeneous. The mean color...

Using HST/COS/STIS and HIRES/Keck high-resolution spectra, we have studied a remarkable H i absorbing complex at z = 0.672 toward the quasar Q1317+277. The absorption has velocity spread of Δv 1600 km s−1, comprises 21 Voigt profile components, resides an impact parameter D 58 kpc from bright, high-mass (log Mvir/M☉ ≃ 13.7) elliptical galaxy that is deduced to 6 Gyr old, solar metallicity stellar population. Ionization models suggest majority structure cold gas surrounding shock-heated cloud...

We study the circumgalactic medium (CGM) of a z=0.54 simulated dwarf galaxy using hydroART simulations. present our analysis methods, which emulate observations, including objective absorption line detection, apparent optical depth (AOD) measurements, Voigt profile (VP) decomposition, and ionization modeling. By comparing inferred CGM gas properties from lines directly to selected by low HI MgII, higher CIV OVI absorption, we examine how well observational methods recover "true" gas. In this...