The Morphology-Density-Relation: Impact on the Satellite Fraction

Abstract

In the past years several authors studied the abundance of satellites around galaxies in order to better estimate the halo masses of host galaxies. To investigate this connection, we analyze galaxies with $M_{\mathrm{star}}\ge 10^{10}{M}_{\odot }$ from the hydrodynamical cosmological simulation Magneticum. We find that the satellite fraction of centrals is independent of their morphology. With the exception of very massive galaxies at low redshift, our results do not support the assumption that the dark matter (DM) haloes of spheroidal galaxies are significantly more massive than those of disc galaxies at fixed $M_{\mathrm{star}}$. We show that the density-morphology-relation starts to build up at $z\sim 2$ and is independent of the star-formation properties of central galaxies. We conclude that environmental quenching is more important for satellites than for centrals. Our simulations indicate that conformity is already in place at $z=2$, where formation redshift and current star-formation rate (SFR) of central and satellite galaxies correlate. Centrals with low SFRs have formed earlier (at fixed $M_{\mathrm{star}}$) while centrals with high SFR formed later, with typical formation redshifts well in agreement with observations. However, we confirm the recent observations that the apparent number of satellites of spheroidal galaxies is significantly larger than for disc galaxies. This difference completely originates from the inclusion of companion galaxies, i.e. galaxies that do not sit in the potential minimum of a DM halo. Thus, due to the density-morphological-relation the number of satellites is not a good tracer for the halo mass, unless samples are restricted to the central galaxies of DM haloes.

17 pages, submitted to MNRAS, www.magneticum.org

References in corpus (8)

• Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
• Structure and star formation in galaxies out to z=3: evidence for surface density dependent evolution and upsizing
• Chemical enrichment of galaxy clusters from hydrodynamical simulations
• A refined sub-grid model for black hole accretion and AGN feedback in large cosmological simulations
• Evolution in the Halo Masses of Isolated Galaxies between z~1 and z~0: From DEEP2 to SDSS
• Satellite abundances around bright isolated galaxies
• The Redshift Evolution of the Mean Temperature, Pressure, and Entropy Profiles in 80 SPT-Selected Galaxy Clusters
• The stellar-to-halo mass relations of local galaxies segregates by color

Cited by in corpus (32)

• Gone after one orbit: How cluster environments quench galaxies
• The SAMI Galaxy Survey: comparing 3D spectroscopic observations with galaxies from cosmological hydrodynamical simulations
• Cosmological simulations of black hole growth II: how (in)significant are merger events for fuelling nuclear activity?
• Metallicity gradients in the globular cluster systems of early-type galaxies: In-situ and accreted components?
• The Young and the Wild: What happens to Protoclusters forming at z = 4?
• The effect of baryons in the cosmological lensing PDFs
• Massive disc galaxies in cosmological hydrodynamical simulations are too dark matter-dominated
• Kinematics of Simulated Galaxies II: Probing the Stellar Kinematics of Galaxies out to Large Radii
• Accreted or Not Accreted? The Fraction of Accreted Mass in Galaxies from Simulations and Observations
• The eROSITA view of the Abell 3391/95 field: a case study from the Magneticum cosmological simulation
• SDSS-IV MaNGA: Uncovering the Angular Momentum Content of Central and Satellite Early-type Galaxies
• Cosmology with the pairwise kinematic SZ effect: Calibration and validation using hydrodynamical simulations
• Rise and fall of post-starburst galaxies in Magneticum Pathfinder
• Baryons Shaping Dark Matter Haloes
• Declining rotation curves at $z=2$ in $\Lambda$CDM galaxy formation simulations
• A stream come true: Connecting tidal tails, shells, streams, and planes with galaxy kinematics and formation history
• Galaxy Lookback Evolution Models -- a Comparison with Magneticum Cosmological Simulations and Observations
• Decomposition of galactic X-ray emission with Phox: Contributions from hot gas and XRBs
• Detecting Galaxy Groups and AGNs populating the local Universe in the eROSITA era
• Characterising Tidal Features Around Galaxies in Cosmological Simulations
• Measuring Dark Matter in Galaxies: The Mass Fraction Within 5 Effective Radii
• Detecting clusters and groups of galaxies populating the local Universe in large optical spectroscopic surveys
• The shape alignment of satellite galaxies in galaxy pairs in SDSS
• Environmental dependence of AGN activity and star formation in galaxy clusters from Magneticum simulations
• Galaxy shapes in Magneticum. I. Connecting stellar and dark matter shapes to dynamical and morphological galaxy properties and the large-scale structure
• Circumgalactic Medium on the Largest Scales: Detecting X-ray Absorption Lines with Large-Area Microcalorimeters
• Intrinsic shapes of Brightest Cluster Galaxies
• Testing the SZ-based tomographic approach to the thermal history of the universe with pressure-density cross-correlations: Insights from the Magneticum simulation
• ΛCDM with baryons vs. MOND: the time evolution of the universal acceleration scale in the Magneticum simulations
• Radial X-ray profiles of simulated galaxies: Contributions from hot gas and XRBs
• Die Hard: The On-Off-Cycle of Galaxies on the Star Formation Main Sequence
• Extending the SAGA Survey (xSAGA) I: Satellite Radial Profiles as a Function of Host Galaxy Properties