The interplay of star formation and supernova (SN) feedback in galaxy formation is a key element for understanding galaxy evolution. Since these processes occur at small scales, it is necessary to have sub-grid models that recover their evolution and environmental effects at the scales reached by cosmological simulations. We simulate the same spiral galaxy inhabiting a Milky Way (MW) size halo in a cosmological environment changing the sub-grid models for SN feedback and star formation. We test combinations of the Schmidt law and a multi-freefall based star formation with delayed cooling feedback or mechanical feedback. We reach a resolution of 35 pc in a zoom-in box of 36 Mpc. For this, we use the code RAMSES with the implementation of gas turbulence in time and trace the local hydrodynamical features of the star-forming gas. Finally, we compare the galaxies at redshift 0 with global and interstellar medium observations in the MW and local spiral galaxies. The simulations show successful comparisons with observations. Nevertheless, diverse galactic morphologies are obtained from different numerical implementations. We highlight the importance of detailed modelling of the star formation and feedback processes, especially when increasing the resolution of simulations. Future improvements could alleviate the degeneracies exhibited in our simulated galaxies under different sub-grid models.
A clear prediction of the Cold Dark Matter model is the existence of cuspy dark matter halo density profiles on all mass scales. This is not in agreement with the observed rotation curves of spiral galaxies, challenging on small scales the otherwise successful CDM paradigm. In this work we employ high resolution cosmological hydro-dynamical simulations to study the effects of dissipative processes on the inner distribution of dark matter in Milky-Way like objects (M~1e12 Msun). Our simulations include supernova feedback, and the effects of the radiation pressure of massive stars before they ex…
The kinematic dispersions of disc stars can be used to measure the dynamic contributions of baryons to the rotation curves of spiral galaxies and hence to trace the amount and distribution of the remaining dark matter. However, the simple single-component infinite disc model traditionally used to convert stellar dispersions to mass-densities is no longer adequate. The dark matter halo has a significant effect upon the stellar dispersions for any non-maximal disc. The correction for cuspy dark matter halos is particularly large, suggesting that such models are not consistent with the observed s…
We study three cosmological hydrodynamical simulations of Milky Way(MW)-sized halos including a comparison with the dark matter(DM)-only counterparts. We find one of our simulated galaxies with interesting MW-like features. Thanks to a consistently tuned star formation rate and supernovae feedback we obtain an extended disk and a flat rotation curve with a satisfying circular velocity and a reasonable DM density in the solar neighbourhood. Mimicking observational methods, we re-derive the stellar mass and obtain stellar-to-halo mass ratios reduced by more than 50\%. We show the interaction bet…
Galaxies and their dark-matter halos have posed several challenges to the Dark Energy plus Cold Dark Matter (LCDM) cosmological model. These discrepancies between observations and theory intensify for the lowest-mass (`dwarf') galaxies. LCDM predictions for the number, spatial distribution, and internal structure of low-mass dark-matter halos have historically been at odds with observed dwarf galaxies, but this is partially expected, because many predictions modeled only the dark-matter component. Any robust LCDM prediction must include, hand-in-hand, a model for galaxy formation to understand…
Many different studies have shown that a wealth of cosmological information resides on small, non-linear scales. Unfortunately, there are two challenges to overcome to utilize that information. First, we do not know the optimal estimator that will allow us to retrieve the maximum information. Second, baryonic effects impact that regime significantly and in a poorly understood manner. Ideally, we would like to use an estimator that extracts the maximum cosmological information while marginalizing over baryonic effects. In this work we show that neural networks can achieve that. We made use of d…
In the present paper, we compare the predictions of two well known mechanisms considered able to solve the cusp/core problem (a. supernova feedback; b. baryonic clumps-DM interaction) by comparing their theoretical predictions to recent observations of the inner slopes of galaxies with masses ranging from dSphs to normal spirals. We compare the $α$-$V_{\rm rot}$ and the $α$-$M_{\ast}$ relationships, predicted by the two models with high resolution data coming from \citep{Adams2014,Simon2005}, LITTLE THINGS \citep{Oh2015}, THINGS dwarves \citep{Oh2011a,Oh2011b}, THINGS spirals \citep{Oh2015}, S…
We recover spiral and barred spiral patterns in disk galaxy simulations with a Wave Dark Matter (WDM) background (also known as Scalar Field Dark Matter (SFDM), Ultra-Light Axion (ULA) dark matter, and Bose-Einstein Condensate (BEC) dark matter). Here we show how the interaction between a baryonic disk and its Dark Matter Halo triggers the formation of spiral structures when the halo is allowed to have a triaxial shape and angular momentum. This is a more realistic picture within the WDM model since a non-spherical rotating halo seems to be more natural. By performing hydrodynamic simulations,…
Cosmological simulations of the same spiral galaxy: satellite properties, the role of baryonic physics and star formation history in shaping dark matter cores/cusps
Gravitational lensing is a powerful probe of the mass distribution of galaxy clusters and cosmology. However, accurate measurements of the cluster mass profiles are limited by uncertainties in cluster astrophysics. In this work, we present a physically motivated model of baryonic effects on the cluster mass profiles, which self-consistently takes into account the impact of baryons on the concentration as well as mass accretion histories of galaxy clusters. We calibrate this model using the Omega500 hydrodynamical cosmological simulations of galaxy clusters with varying baryonic physics. Our mo…
Providing a theoretical basis for the baryonic Tully-Fisher Relation (BTFR; baryonic mass vs rotational velocity in spiral galaxies) in the LCDM paradigm has proved problematic. Simple calculations suggest too low a slope and too high a scatter, and recent semi-analytic models and numerical galaxy simulations typically fail to reproduce some aspects of the relation. Furthermore, the assumptions underlying one model are often inconsistent with those behind another. This paper aims to develop a rigorous prediction for the BTFR in the context of LCDM, using only a priori expected effects and rela…
We present a novel 2D flux density model for observed HI emission lines combined with a Bayesian stacking technique to measure the baryonic Tully-Fisher relation below the nominal detection threshold. We simulate a galaxy catalogue, which includes HI lines described either with Gaussian or busy function profiles, and HI data cubes with a range of noise and survey areas similar to the MeerKAT International Giga-Hertz Tiered Extragalactic Exploration (MIGHTEE) survey. With prior knowledge of redshifts, stellar masses and inclinations of spiral galaxies, we find that our model can reconstruct the…
We present and test a framework that models the three-dimensional distribution of mass in the Universe as a function of cosmological and astrophysical parameters. Our approach combines two different techniques: a rescaling algorithm that modifies the cosmology of gravity-only N-body simulations, and a baryonification algorithm which mimics the effects of astrophysical processes induced by baryons, such as star formation and AGN feedback. We show how this approach can accurately reproduce the effects of baryons on the matter power spectrum of various state-of-the-art hydro-dynamical simulations…
The diverse nature of spiral arms in the Auriga Superstars cosmological hydrodynamic simulations
Liverpool John Moores University（利物浦约翰摩尔斯大学）；Durham University（杜伦大学）；Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理学研究所）；Universidad de La Serena（拉塞雷纳大学）；Cardiff University（卡迪夫大学）；Universität Zürich（苏黎世大学）
An extensive catalog of spatially-resolved galaxy rotation curves and multi-band optical light profiles for 1752 observed spiral galaxies is assembled to explore the drivers of diversity in galaxy structural parameters, rotation curve shapes, and stellar mass profiles. Similar data were extracted from the NIHAO galaxy simulations to identify any differences between observations and simulations. Several parameters, including the inner slope "S" of a rotation curve (RC), were tested for diversity. Two distinct populations are found in observed and simulated galaxies; (i) blue, low mass spirals w…
For disk galaxies (spirals and irregulars), the inner circular-velocity gradient (inner steepness of the rotation curve) correlates with the central surface brightness with a slope of ~0.5. This implies that the central dynamical mass density scales almost linearly with the central baryonic density. Here I show that this empirical relation is consistent with a simple model where the central baryonic fraction f_bar(0) is fixed to 1 (no dark matter) and the observed scatter is due to differences in the baryonic mass-to-light ratio M_bar/L (ranging from 1 to 3 in the R-band) and in the characteri…
We derive the specific baryonic angular momentum of five gas rich dwarf galaxies from HI kinematics complemented by stellar mass profiles. Since the gas mass of these galaxies is much larger than the stellar mass, the angular momentum can be determined with relatively little uncertainty arising from the uncertainties in the stellar mass to light ratio. We compare the relation between the specific baryonic angular momentum (j) and the total baryonic mass (M) for these galaxies with that found for spiral galaxies. Our combined sample explores the j-M plane over 3 orders of magnitude in baryon ma…
We study the HI K-band Tully-Fisher relation and the baryonic Tully-Fisher relation for a sample of 16 early-type galaxies, taken from the ATLAS3D sample, which all have very regular HI disks extending well beyond the optical body (> 5 R_eff). We use the kinematics of these disks to estimate the circular velocity at large radii for these galaxies. We find that the Tully-Fisher relation for our early-type galaxies is offset by about 0.5-0.7 magnitudes from the relation for spiral galaxies. The residuals with respect to the spiral Tully-Fisher relation correlate with estimates of the stellar mas…
We study the distribution of cold dark matter (CDM) in cosmological simulations from the FIRE (Feedback In Realistic Environments) project, for $M_{\ast}\sim10^{4-11}\,M_{\odot}$ galaxies in $M_{\rm h}\sim10^{9-12}\,M_{\odot}$ halos. FIRE incorporates explicit stellar feedback in the multi-phase ISM, with energetics from stellar population models. We find that stellar feedback, without "fine-tuned" parameters, greatly alleviates small-scale problems in CDM. Feedback causes bursts of star formation and outflows, altering the DM distribution. As a result, the inner slope of the DM halo profile (…
Princeton University（普林斯顿大学）；Flatiron Institute（熨斗研究所）；Columbia University（哥伦比亚大学）；University of Connecticut（康涅狄格大学）
We train neural networks to perform likelihood-free inference from $(25\,h^{-1}{\rm Mpc})^2$ 2D maps containing the total mass surface density from thousands of hydrodynamic simulations of the CAMELS project. We show that the networks can extract information beyond one-point functions and power spectra from all resolved scales ($\gtrsim 100\,h^{-1}{\rm kpc}$) while performing a robust marginalization over baryonic physics at the field level: the model can infer the value of $Ω_{\rm m} (\pm 4\%)$ and $σ_8 (\pm 2.5\%)$ from simulations completely different to the ones used to train it.
Residuals between measured galactic radii and those predicted by the Fundamental Plane (FP) are possible tracers of weak lensing magnification. However, observations have shown these to be systematically correlated with the large-scale structure. We use the Horizon-AGN hydrodynamical cosmological simulation to analyse these intrinsic size correlations (ISCs) for both elliptical (early-type) and spiral (late-type) galaxies at $z=0.06$. We fit separate FPs to each sample, finding similarly distributed radius residuals, $λ$, in each case. We find persistent $λλ$ correlations over three-dimensiona…
We present and discuss results from chemical evolution models for M33. For our models we adopt a galactic formation with an inside-out scenario. The models are built to reproduce three observational constraints of the M33 disk: the radial distributions of the total baryonic mass, the gas mass, and the O/H abundance. From observations, we find that the total baryonic mass profile in M33 has a double exponential behavior, decreasing exponentially for r<= 6 kpc, and increasing lightly for r > 6 kpc due to the increase of the gas mass surface density. To adopt a concordant set of stellar and H II …
Scaling relations among structural and kinematical features of 79 late-type spiral and dwarf irregular galaxies of the SPARC sample are revisited or newly established. The mean central surface brightness <$μ_{0,[3.6]}$> = 19.63 $\pm$ 0.11 mag arcsec$^{-2}$ allows for a clear-cut distinction between low and high surface brightness galaxies irrespective of luminosity. The geometry of rotation curves is characterized by the relation $dv(R_d)/dr \approx v_{max}/R_{max}$. For the rotation curve decompositions we apply dark matter halos of Burkert and of pseudo-isothermal type. The disk mass-to-ligh…
We use a high resolution cosmological zoom simulation of a Milky Way-sized halo to study the observable features in velocity and metallicity space associated with the dynamical influence of spiral arms. For the first time, we demonstrate that spiral arms, that form in a disc in a fully cosmological environment with realistic galaxy formation physics, drive large-scale systematic streaming motions. In particular, on the trailing edge of the spiral arms the peculiar galacto-centric radial and azimuthal velocity field is directed radially outward and azimuthally backward, whereas it is radially i…
We present a neural-network emulator for baryonic effects in the non-linear matter power spectrum. We calibrate this emulator using more than 50,000 measurements in a 15-dimensional parameters space, varying cosmology and baryonic physics. Baryonic physics is described through a baryonification algorithm, that has been shown to accurately capture the relevant effects on the power spectrum and bispectrum in state-of-the-art hydrodynamical simulations. Cosmological parameters are sampled using a cosmology-rescaling approach including massive neutrinos and dynamical dark energy. The specific quan…
In order to determine the observable signatures of modified gravity theories, it is important to consider the effect of baryonic physics. We use a modified version of the ISIS code to run cosmological hydrodynamic simulations to study degeneracies between modified gravity and radiative hydrodynamical processes. Of these, one was the standard $Λ$CDM model and four were variations of the Symmetron model. For each model we ran three variations of baryonic processes: non-radiative hydrodynamics; cooling and star formation; and cooling, star formation, and supernova feedback. We construct stacked g…
A first measurement of baryonic feedback with Fast Radio Bursts
Argelander-Institut für Astronomie, Universität Bonn（波恩大学天体物理研究所）；Universitäts-Sternwarte, Fakultät für Physik, Ludwig-Maximilians Universität München（慕尼黑大学物理学院天文台）；Excellence Cluster ORIGINS（ORIGINS卓越集群）
We study the vertical perturbations in the galactic disc of the Milky Way-size high-resolution hydrodynamical cosmological simulation named GARROTXA. We detect phase spirals in the vertical projection $Z- V_{Z}$ of disc's stellar particles for the first time in this type of simulations. Qualitatively similar structures were detected in the recent Gaia data, and their origin is still under study. In our model the spiral-like structures in the phase space are present in a wide range of times and locations across the disc. By accounting for an evolving mix of stellar populations, we observe that,…
Calibrating baryonic feedback with weak lensing and fast radio bursts
Ruhr University Bochum（鲁尔大学波鸿分校）；Argelander-Institut für Astronomie, Universität Bonn（波恩大学阿根兰德天文学研究所）；Ludwig-Maximilians Universität München（慕尼黑路德维希-马克西米利安大学）；Excellence Cluster ORIGINS（ORIGINS卓越集群）
The near proportionality between HI and dark matter in outer galactic disks prompted us to run N-body simulations of galactic disks in which the observed gas content is supplemented by a dark gas component representing between zero and five times the visible gas content. While adding baryons in the disk of galaxies may solve some issues, it poses the problem of disk stability. We show that the global stability is ensured if the ISM is multiphased, composed of two partially coupled phases, a visible warm gas phase and a weakly collisionless cold dark phase corresponding to a fraction of the uns…
We present gas and stellar kinematics of a high-resolution zoom-in cosmological chemodynamical simulation, which fortuitously captures the formation and evolution of a star-forming barred spiral galaxy, from redshift $z\sim3$ to $z\sim2$ at the peak of the cosmic star formation rate. The galaxy disc grows by accreting gas and substructures from the environment. The spiral pattern becomes fully organised when the gas settles from a thick (with vertical dispersion $σ_{v} >$ 50 km/s) to a thin ($σ_{v} \sim 25$ km/s) disc component in less than 1 Gyr. Our simulated disc galaxy also has a central X…
Within the standard hierarchical structure formation scenario, Milky Way-mass dark matter haloes have hundreds of dark matter subhaloes with mass $\gtrsim 10^8 \, {\rm M_{\odot}}$. Over the lifetime of a galactic disc a fraction of these may pass close to the central region and interact with the disc. We extract the properties of subhaloes, such as their mass and trajectories, from a realistic cosmological simulation to study their potential effect on stellar discs. We find that massive subhalo impacts can generate disc heating, rings, bars, warps, lopsidedness as wells as spiral structures in…
A significant fraction of spiral galaxies are red, gas-poor, and have low star formation rates (SFRs). We study these unusual objects using the IllustrisTNG100 simulation. Among 1912 well-resolved disk galaxies selected from the last simulation output, we identify 377 red objects and describe their properties and origins using a few representative examples. The simulated red spirals turn out to be typically very gas-poor, have very low SFRs, are more metal-rich, and have larger stellar masses than the remaining disks. Only about 13% of red spirals suffered strong mass loss and thus could have …
Recent observations of the fields surrounding a few Milky-Way-like galaxies in the local Universe have become deep enough to enable investigations of the predictions of the standard LCDM cosmological model down to small scales outside the Local Group. Motivated by an observed correlation between the number of dwarf satellites (N_sat) and the bulge-to-total baryonic mass ratios (B/T) of the three main galaxies in the Local Group, i.e. the Milky Way, Andromeda, and Triangulum (M33), we use published data of three well-studied galaxies outside the Local Group, namely M81, Centaurus A, and M101, a…
We extend the work of Chang & Chakrabarti (2011) to find simple scaling relations between the density response of the gas disk of a spiral galaxy and the pericenter distance and mass ratio of a perturbing satellite. From the analysis of results from a test particle code, we obtained a simple scaling relation for the density response due to a single satellite interacting with a galactic disk, over a wide range of satellite masses and pericenter distances. We have also explored the effects of multiple satellites on the galactic disk, focusing on cases that are commonly found in cosmological simu…
The dark matter (DM) haloes around spiral galaxies appear to conspire with their baryonic content: empirically, significant amounts of DM are inferred only below a universal characteristic acceleration scale. Moreover, the discrepancy between the baryonic and dynamical mass, which is usually interpreted as the presence of DM, follows a very tight mass discrepancy acceleration (MDA) relation. Its universality, and its tightness in spiral galaxies, poses a challenge for the DM interpretation and was used to argue in favour of MOdified Newtonian Dynamics (MOND). Here, we test whether or not this …
We present a quantification of the properties of bars in two N-body+SPH cosmological simulations of spiral galaxies, named GA and AqC. The initial conditions were obtained using the zoom-in technique and represent two dark matter (DM) halos of $2-3\times10^{12}\ {\rm M}_\odot$, available at two different resolutions. The resulting galaxies are presented in the companion paper of Murante et al. (2014). We find that the GA galaxy has a bar of length $8.8$ kpc, present at the two resolution levels even though with a slightly different strength. Classical bar signatures (e.g. pattern of streaming …
The Luminous Convolution Model (LCM) is an empirical formula, based on a heuristic convolution of Relativistic transformations, which makes it possible to predict the observed rotation curves of a broad class of spiral galaxies from luminous matter alone. Since the LCM is independent of distance estimates or dark matter halo densities, it is the first model of its kind which constrains luminous matter modeling directly from the observed spectral shifts of characteristic photon emission/absorption lines. In this paper we present the LCM solution to a diverse sample of twenty-five (25) galaxies …
We describe and test a novel Dark Matter Annihilation Feedback (DMAF) scheme that has been implemented into the well known cosmological simulation code \textsf{GADGET-2}. In the models considered here, dark matter can undergo self-annihilation/decay into radiation and baryons. These products deposit energy into the surrounding gas particles and then the dark matter/baryon fluid is self-consistently evolved under gravity and hydrodynamics. We present tests of this new feedback implementation in the case of idealised dark matter halos with gas components for a range of halo masses, concentration…
We examine the azimuthal variations in gas-phase metallicity profiles in simulated Milky Way mass disk galaxies from the Feedback in Realistic Environments (FIRE-2) cosmological zoom-in simulation suite, which includes a sub-grid turbulent metal mixing model. We produce spatially resolved maps of the disks at $z \approx 0$ with pixel sizes ranging from 250 to 750~pc, analogous to modern integral field unit (IFU) galaxy surveys, mapping the gas-phase metallicities in both the cold & dense gas and the ionized gas correlated with HII regions. We report that the spiral arms alternate in a pattern …
The interstellar gas in spiral galaxies can constitute a significant fraction of the baryon mass and it has been demonstrated that the sum of stellar and gas components correlates well with the kinematic signature of the total mass content, the widths of HI line profiles. The correlation of baryonic mass with HI line widths is used here to obtain distances for 9984 galaxies extending to ~0.05c. The sample is HI flux limited and a correction is required to account for an HI selection bias. The absolute scale is established by 64 galaxies with known distances from studies of Cepheid variables an…
Massive and diffuse haloes of hot gas (coronae) are important intermediaries between cosmology and galaxy evolution, storing mass and angular momentum acquired from the cosmic web until eventual accretion on to star-forming discs. We introduce a method to reconstruct the rotation of a galactic corona, based on its angular momentum distribution (AMD). This allows us to investigate in what conditions the angular momentum acquired from tidal torques can be transferred to star forming discs and explain observed galaxy-scale processes, such as inside-out growth and the build-up of abundance gradien…
The rotation dynamics of spiral galaxies is modeled using a sum of two mass distributions: a spherical bulge and a thin disk. The density functions representing these mass distributions are calculated from the total angular momentum of the galaxy and known rotation curves. When both bulge and disk density functions are assumed to be smooth and are given a value of zero beyond the edge of the galaxy, a unique solution is obtained. Moreover, the calculated density functions show that constant rotation curves are obtained from a nearly exponential luminosity profile with a dark matter distributio…
Dust in spiral galaxies produces emission in the far-infrared (FIR) and internal absorption in visible wavelengths. However, the relation of the two amounts is not trivial because optical absorption may saturate, but the FIR emission does not. Moreover, the volume concentration of dust plays a role in the relation of absorption and emission, which depends on the size of the galaxy. We explore the relation of these three quantities. In order to understand the geometrical problem, we developed a model of dust distribution. We also investigated the relation of the three variables with real data o…
Super spirals are the most massive star-forming disk galaxies in the universe (Ogle et al. 2016, 2019). We measured rotation curves for 23 massive spirals and find a wide range of fast rotation speeds (240-570 km/s), indicating enclosed dynamical masses of 0.6 - 4E12 Msun. Super spirals with mass in stars log Mstars / Msun > 11.5 break from the baryonic Tully-Fisher relation (BTFR) established for lower mass galaxies. The BTFR power-law index breaks from 3.75 +/- 0.11 to 0.25 +/- 0.41 above a rotation speed of 340 km/s. Super spirals also have very high specific angular momenta that break from…
Dwarf irregular galaxies with extended HI disk distributions, such as DDO 154, allow measurement of rotation curves, hence deduction of dark matter halo properties to large radial distances, up to several times the optical radius. These galaxies contain a huge reservoir of dark matter halo, which dominates over most of disk. We study the effect of the dark matter halo on small-scale spiral features by carrying out the local, non-axisymmetric perturbation analysis in the disks of five such late-type, gas-rich dwarf irregular galaxies, namely, DDO 154, NGC 3741, DDO 43, NGC 2366, and DDO 168 whi…
We compare the Baryonic Tully-Fisher relation (BTFR) of simulations and observations of galaxies ranging from dwarfs to spirals, using various measures of rotational velocity Vrot. We explore the BTFR when measuring Vrot at the flat part of the rotation curve, Vflat, at the extent of HI gas, Vlast, and using 20% (W20) and 50% (W50) of the width of HI line profiles. We also compare with the maximum circular velocity of the parent halo, Vmax, within dark matter only simulations. The different BTFRs increasingly diverge as galaxy mass decreases. Using Vlast one obtains a power law over four order…
