Encyclopedia Magneticum: Scaling Relations from Cosmic Dawn to Present Day

Abstract

Galaxy and halo scaling relations, connecting a broad range of parameters, are well established from observations. The origin of many of these relations and their scatter is still a matter of debate. It remains a sizable challenge for models to simultaneously and self-consistently reproduce as many scaling relations as possible. We introduce the Magneticum Pathfinder hydrodynamical cosmological simulation suite, to date the suite that self-consistently covers the largest range in box volumes and resolutions. It is the only cosmological simulation suite that is tuned on the hot gas content of galaxy clusters instead of the stellar mass function. By assessing the successes and shortcomings of tuning to the hot gas component of galaxy clusters, we aim to further our understanding of the physical processes shaping the Universe. We analyze the importance of the hot and cold gas components for galaxy and structure evolution. We analyze 28 scaling relations, covering large-scale global parameters as well as internal properties for halos ranging from massive galaxy clusters down to galaxies, and show their predicted evolution from z=4 to z=0 in comparison with observations. These include the halo-to-stellar-mass and Kennicutt--Schmidt relations, the cosmic star formation rate density as well as the Fundamental Plane. Magneticum Pathfinder matches a remarkable number of the observed scaling relations from z=4 to z=0, including challenging relations like the number density of quiescent galaxies at cosmic dawn, the mass--size evolution, the mass--metallicity relation, the Magorrian relation, and the temperature--mass relation. We compile our data to allow for straightforward future comparisons. Galaxy properties and scaling relations arise naturally and the large scatter in observables at high redshift is crucial to distinguish the various galaxy formation models reproducing the z=0 relations.

Figures (42)

• Figure 1: Visualization of the different boxes of Magneticum Pathfinder. Zooming from the largest scales (Gpc scales) into galaxy clusters (Mpc scales) and further down onto individual galaxies (tens of kpc scales). Top: The simulation volumes from Magneticum Pathfinder to scale. The inlay panels at the top show the dark matter density. The large background panel shows the dark matter density transitioning into the gas density from top to bottom for Box0. Bottom left: A massive galaxy cluster from Box2 and its large-scale environment. Shown is the gas density split into a hot (red-yellow) and a cold (blue) component, with the temperature splitting the two phases at $T_\mathrm{cut}=10^4\mathrm{K}$. Bottom center: Zoom in on the same galaxy cluster from Box2, where the stellar component is visualized using Splotch dolag:2008 and the gas surface density contours are overlaid in white. The image has a side length of 5.59 cMpc. Bottom right: Two galaxies taken from Box4, where the top shows a massive elliptical galaxy and the bottom an edge-on disk galaxy of MW-mass. Both images were created using the dust radiative transfer code Skirtbaes:2011camps:2020.
• Figure 2: Placing simulations in resolution context. Left panel: Evolution of the number of resolution elements used in (hydrodynamical) cosmological simulations over the last thirty years (inspired by genel:2014). The Magneticum Pathfinder simulations are marked in blue hirschmann:2014teklu:2015saro:2014bocquet:2016ragagnin:2017webportal, and the Magneticum Pathfinder local Universe spinoff SLOW is shown in light blue dolag:2023. Light gray squares mark hydrodynamical simulations without BH treatment (01: metzler:1994; 02: katz:1996; 03: pearce:1999; 04: dave:2001; 05: murali:2002; 06: springel:2003_cosmosim; 07: borgani:2004; 08: kay:2004; Coruscant: dolag:2005; 09: oppenheimer:2008; 10: planelles:2009; 11: dave:2011; 12: deboni:2011; 13: cui:2012; 14: vogelsberger:2012; 16: dave:2013); dark gray diamonds mark hydrodynamical simulations including BH treatment (BHCosmo: dimatteo:2008; OWLS: schaye:2010; 15: puchwein:2013; OWLS: vanDaalen:2014; HorizonAGN: dubois:2014; Illustris: vogelsberger:2014; Eagle: schaye:2015; MassiveBlackII: khandai:2015; IllustrisTNG: springel:2018; Simba: dave:2019; IllustrisTNG-50: nelson:2019; FIREbox: feldmann:2023; MTNG: pakmor:2023; Flamingo: schaye:2023); and black triangles mark dark matter only simulations (Millenium: springel:2005_mil; MilleniumXXL: angulo:2012; DarkSky: skillman:2014; PKDGRAV3: potter:2017; TianNu: emberson:2017; OuterRim: heitmann:2019; LastJourney: heitmann:2021; Uchuu: ishiyama:2021; Farpoint: frontiere:2022; MTNG-N: hernandezAguayo:2023). Right Panel: Baryonic particle mass versus box length for the subset of hydrodynamical simulations including BH treatment. The number of resolution elements is indicated by the pink dotted lines. For the Magneticum Pathfinder simulations where one gas particles can spawn up to four stellar particles, two symbols are shown: the open circles mark the gas resolution before spawning, solid circles mark the average stellar particle masses. In addition to the simulations shown in the left panel, we also include the Bahamas simulations mccarthy:2017.
• Figure 3: Stellar particle resolution for Milky-Way mass galaxies versus the stellar mass ranges encompassed by different simulation suites including both hydrodynamical cosmological simulations (round circles and solid lines) and hydrodynamical zoom-in simulations (diamonds and dash-dotted lines). The Magneticum Pathfinder simulations are shown in blue, with the SLOW simulation dolag:2023 marked in light blue. The rightmost symbol on each line marks the virial mass of the most massive structure in that simulation, while the length of the lines indicates a mass limit of 1000 DM particles in a halo. For Zoom simulations, the leftmost diamond marks the virial mass of the smallest zoom object in the given suite. Pink vertical lines mark the virial mass of the Milky Way (dotted), the threshold splitting galaxy groups from clusters ($M_\mathrm{vir}=10^{14}\,M_\odot$, dash-dot-dot-dotted), and the virial mass of the Coma cluster (dashed). Included for comparison are FIREbox feldmann:2023, TNG-50 nelson:2019, Eagle schaye:2015, Romulus-C with a single cluster tremmel:2019, Illustris-TNG-100 and Illustris-TNG-300 springel:2018pillepich:2018, Horizon-AGN dubois:2014, Hydrangea bahe:2017, TNG-Clusters zooms nelson:2024, Simba dave:2019, MilleniumTNG pakmor:2023, Flamingo schaye:2023, Rhapsody-G Cluster Zooms hahn:2017, The-300 cluster zooms cui:2018, and the Bahamas simulations mccarthy:2017.
• Figure 4: The halo mass function obtained from the Magneticum Pathfinder simulations, at the redshifts of $z=4$, $2$, $1$, and $0$. Shown are: Box5/xhr (gray, $z=4$, $2$), Box4/uhr (blue, $z=4$, $2$, $1$, $0$), Box3/uhr (turquoise, $z=4$, $2$), Box2/hr (pink, $z=4$, $2$, $1$, $0$), Box2b/hr (pink, $z=4$, $2$, $1$), andBox0/mr (gold, $z=4$, $2$, $1$, $0$).
• Figure 5: Results of the Keplerian Ring test (left column) and the Kelvin-Helmholtz instability test (right column). The upper row shows the performance of the old SPH scheme, while the performance of the new scheme presented by beck:2015, which was used to carry out the Magneticum Pathfinder simulations, is shown in the lower row. In the Keplerian Ring test particles are orbiting a central point mass, and it is a useful test for investigations of galactic disk rotation and stability. Historic SPH (top left panel) contains too much artificial viscosity and the ring becomes unstable after two dynamical times ($T=2\pi$). In contrast, our updated SPH scheme (bottom left panel) is able to preserve the stability of the ring for long times. Additionally, the improved prescriptions of SPH allow the Kelvin-Helmholtz instability to develop and form prominent roll-ups (bottom right panel), to initiate perturbations between two shearing layers. Historic SPH again is unable to perform fluid phase mixing and development of the instability (top right panel).