Dwarf Galaxy Number Counts within 25 Mpc: Predictions from Local Group Analogues in TNG50

Abstract

The modern generation of wide-field galaxy surveys, such as LSST, Euclid and Roman, will enable studies of dwarf galaxies $(10^6\le M_{\ast }/M_{\odot }\le 10^9)$ beyond the Local Group (LG) in unprecedented detail. Improved theoretical understanding of this population is necessary to guide these observations, since predictions in this regime are generally limited to specific environments like the LG. We present predictions for the population of dwarf galaxies from the TNG50 run of the IllustrisTNG suite of cosmological hydrodynamical simulations, focusing on the environments within $1<D/\mathrm{Mpc}<25$ of LG analogues at $z=0$. In the simulated sample, there are $\sim 1,000$ and $\sim 12,000$ dwarf galaxies within $10$ and $25$ Mpc, respectively. We compare our results with the 50 Mpc Galaxy Catalog and estimate that current observations are highly incomplete at low masses: for $10^6\le M_{\ast }/M_{\odot }\le 10^7$ $(-13\lesssim M_r\lesssim -10)$, we find completeness fractions of $\sim 23\%$ within $10$ Mpc and $\sim 4\%$ within $25$ Mpc. The simulated galaxies below the completeness limits of the observations exist in a range of environments, with notable populations of field dwarfs at all distances and satellites around centrals with masses $10^8\lesssim M_{\ast }/M_{\odot }\lesssim 10^{11}$ within $10-25$ Mpc. We find that there are $\sim 8$ times more quiescent dwarf galaxies in the TNG50 sample than are currently cataloged. Our results suggest that upcoming observations should uncover a substantial population of dwarf galaxies, and that $\gtrsim 15\%$ of these will be red, currently quenched galaxies in the field.

submitted to ApJ; 32 pages, 16 figures, 2 tables

References in corpus (101)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• Planck 2015 results. XIII. Cosmological parameters
• A Universal Density Profile from Hierarchical Clustering
• Galactic Stellar and Substellar Initial Mass Function
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• On the variation of the Initial Mass Function
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• LSST: from Science Drivers to Reference Design and Anticipated Data Products
• Populating a cluster of galaxies - I. Results at z=0
• The Average Star Formation Histories of Galaxies in Dark Matter Halos from z=0-8
• Simulating Galaxy Formation with the IllustrisTNG Model
• The observed properties of dwarf galaxies in and around the Local Group
• First results from the IllustrisTNG simulations: matter and galaxy clustering
• First results from the IllustrisTNG simulations: the stellar mass content of groups and clusters of galaxies
• First results from the IllustrisTNG simulations: the galaxy color bimodality
• Small-Scale Challenges to the $\Lambda$CDM Paradigm
• Galaxies on FIRE (Feedback In Realistic Environments): Stellar Feedback Explains Cosmologically Inefficient Star Formation
• Galactic star formation and accretion histories from matching galaxies to dark matter haloes
• First results from the IllustrisTNG simulations: A tale of two elements -- chemical evolution of magnesium and europium
• Simulating galaxy formation with black hole driven thermal and kinetic feedback
• UniverseMachine: The Correlation between Galaxy Growth and Dark Matter Halo Assembly from z=0-10
• First results from the IllustrisTNG simulations: radio haloes and magnetic fields
• A model for cosmological simulations of galaxy formation physics
• First Results from the TNG50 Simulation: The evolution of stellar and gaseous disks across cosmic time
• HyperLEDA. III. The catalogue of extragalactic distances
• The Connection between Galaxies and their Dark Matter Halos
• LCDM-based models for the Milky Way and M31 I: Dynamical Models
• Galaxy And Mass Assembly: Stellar Mass Estimates
• The APOSTLE simulations: solutions to the Local Group's cosmic puzzles
• Eight New Milky Way Companions Discovered in First-Year Dark Energy Survey Data
• The Faintest Dwarf Galaxies
• Improved background subtraction for the Sloan Digital Sky Survey images
• Euclid. I. Overview of the Euclid mission
• Updated Nearby Galaxy Catalog
• Near-Field Cosmology with Metal-Poor Stars
• Eight Ultra-faint Galaxy Candidates Discovered in Year Two of the Dark Energy Survey
• COLOSSUS: A python toolkit for cosmology, large-scale structure, and dark matter halos
• The optical morphologies of galaxies in the IllustrisTNG simulation: a comparison to Pan-STARRS observations
• A Halo-Based Galaxy Group Finder: Calibration and Application to the 2dFGRS
• A Stellar Mass Threshold for Quenching of Field Galaxies
• Galaxy and Mass Assembly (GAMA): The GAMA Galaxy Group Catalogue (G3Cv1)
• A New Milky Way Companion: Unusual Globular Cluster or Extreme Dwarf Satellite?
• Percolation Galaxy Groups and Clusters in the SDSS Redshift Survey: Identification, Catalogs, and the Multiplicity Function
• ELVIS: Exploring the Local Volume in Simulations
• A physical model for cosmological simulations of galaxy formation: multi-epoch validation
• The Size Evolution of Star-forming and Quenched Galaxies in the IllustrisTNG simulation
• The star-formation activity of IllustrisTNG galaxies: main sequence, UVJ diagram, quenched fractions, and systematics
• An accurate physical model for halo concentrations
• The evolution of substructure III: the outskirts of clusters
• Galaxy And Mass Assembly (GAMA): Data Release 4 and the z < 0.1 total and z < 0.08 morphological galaxy stellar mass functions
• The SAGA Survey: I. Satellite Galaxy Populations Around Eight Milky Way Analogs
• Sagittarius II, Draco II and Laevens 3: three new Milky Way satellites discovered in the Pan-STARRS 1 3pi Survey
• The Local Group on FIRE: Dwarf galaxy populations across a suite of hydrodynamic simulations
• Modeling the Effects of Star Formation Histories on Halpha and Ultra-Violet Fluxes in Nearby Dwarf Galaxies
• Milky Way Satellite Census. II. Galaxy--Halo Connection Constraints Including the Impact of the Large Magellanic Cloud
• The SAGA Survey. II. Building a Statistical Sample of Satellite Systems around Milky Way-like Galaxies
• Quenched fractions in the IllustrisTNG simulations: the roles of AGN feedback, environment, and pre-processing
• Quenched fractions in the IllustrisTNG simulations: comparison with observations and other theoretical models
• The Hestia project: simulations of the Local Group
• Galaxy groups in the low-redshift Universe
• Abundance of Field Galaxies
• The detailed structure and the onset of galaxy formation in low-mass gaseous dark matter haloes
• FIREbox: Simulating galaxies at high dynamic range in a cosmological volume
• The faint end of the Centaurus A satellite luminosity function
• The zCOSMOS 20k Group Catalog
• First results from the MADCASH Survey: A Faint Dwarf Galaxy Companion to the Low Mass Spiral Galaxy NGC 2403 at 3.2 Mpc
• The stellar-to-halo mass relation for Local Group galaxies
• Assessing Colour-dependent Occupation Statistics Inferred from Galaxy Group Catalogues
• The Hubble Sequence at $z\sim 0$ in the IllustrisTNG simulation with deep learning
• Cosmicflows-3: Cosmography of the Local Void
• The M101 group complex: new dwarf galaxy candidates and spatial structure
• Discovery of diffuse dwarf galaxy candidates around M101
• The abundance of satellites around Milky Way- and M31-like galaxies with the TNG50 simulation: a matter of diversity
• Resolved Dwarf Galaxy Searches within ~5 Mpc with the Vera Rubin Observatory and Subaru Hyper Suprime-Cam
• Constrained Local UniversE Simulations: A Local Group Factory
• How well does the Friends-of-Friends algorithm recover group properties from galaxy catalogs limited in both distance and luminosity?
• The cumulative star-formation histories of dwarf galaxies with TNG50. I: Environment-driven diversity and connection to quenching
• Environmental Quenching of Low-Mass Field Galaxies
• Hunting Faint Dwarf Galaxies in the Field Using Integrated Light Surveys
• A Self-Calibrating Halo-Based Group Finder: Application to SDSS
• Tracing satellite planes in the Sculptor group: I. Discovery of three faint dwarf galaxies around NGC 253
• The SAGA Survey. III. A Census of 101 Satellite Systems around Milky Way-mass Galaxies
• Hubble Space Telescope Observations of NGC 253 Dwarf Satellites: Discovery of Three Ultra-faint Dwarf Galaxies
• Stellar and dark matter density in the Local Universe
• IQ Collaboratory II: The Quiescent Fraction of Isolated, Low Mass Galaxies Across Simulations and Observations
• The Local Volume Database: a library of the observed properties of nearby dwarf galaxies and star clusters
• The 2MASS redshift survey galaxy group catalogue derived from a graph-theory based friends-of-friends algorithm
• The Local Group in the cosmic web
• One simulation to have them all: performance of the Bias Assignment Method against N-body simulations
• New Local Volume Dwarf Galaxy Candidates from the DESI Legacy Imaging Surveys
• Local Group Analogs in $\Lambda$CDM cosmological simulations
• Constraining Scatter in the Stellar Mass--Halo Mass Relation for Haloes Less Massive than the Milky Way
• Detecting clusters and groups of galaxies populating the local Universe in large optical spectroscopic surveys
• Estimation of the masses in the Local Group by Gradient Boosted Decision Trees
• A census of dwarf galaxy satellites around LMC-mass galaxy NGC 2403
• Particle-based and Meshless Methods with Aboria
• Predictions for the Detectability of Milky Way Satellite Galaxies and Outer-Halo Star Clusters with the Vera C. Rubin Observatory
• PAC in DESI. I. Galaxy Stellar Mass Function into the $10^6{\mathrm{M}}_{\odot }$ Frontier
• Dwarf Galaxies in the TNG50 Field: connecting their Star-formation Rates with their Environments