The feeble giant. Discovery of a large and diffuse Milky Way dwarf galaxy in the constellation of Crater

Abstract

We announce the discovery of the Crater 2 dwarf galaxy, identified in imaging data of the VST ATLAS survey. Given its half-light radius of ~1100 pc, Crater 2 is the fourth largest dwarf in the Milky Way, surpassed only by the LMC, SMC and the Sgr dwarf. With a total luminosity of $M_V\approx -8$, this satellite galaxy is also one of the lowest surface brightness dwarfs. Falling under the nominal detection boundary of 30 mag arcsec${}^{-2}$, it compares in nebulosity to the recently discovered Tuc 2 and Tuc IV and UMa II. Crater 2 is located ~120 kpc from the Sun and appears to be aligned in 3-D with the enigmatic globular cluster Crater, the pair of ultra-faint dwarfs Leo IV and Leo V and the classical dwarf Leo II. We argue that such arrangement is probably not accidental and, in fact, can be viewed as the evidence for the accretion of the Crater-Leo group.

10 pages, 8 figures, accepted by MNRAS; v2 small fixes; v3 accepted version;v4 Added ESO program

References in corpus (16)

• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• Forty-Seven Milky Way-Sized, Extremely Diffuse Galaxies in the Coma Cluster
• The Tidal Evolution of Local Group Dwarf Spheroidals
• The Luminosity Function of the Milky Way Satellites
• The Origin of the Magellanic Stream and Its Leading Arm
• "Skinny Milky Way, Please", says Sagittarius
• Leo V: A Companion of a Companion of the Milky Way Galaxy
• A trio of new Local Group galaxies with extreme properties
• A Hero's Dark Horse: Discovery of an Ultra-Faint Milky Way Satellite in Pegasus
• A new distant Milky Way globular cluster in the Pan-STARRS1 3π survey
• ATLAS lifts the Cup: Discovery of a New Milky Way satellite in Crater
• Discovery of a cold stellar stream in the ATLAS DR1 data
• Discovery of a Faint Outer Halo Milky Way Star Cluster in the Southern Sky
• A Hero's Little Horse: Discovery of a Dissolving Star Cluster in Pegasus
• An Improved Photometric Calibration of the Sloan Digital Sky Survey Imaging Data

Cited by in corpus (172)

• The Faintest Dwarf Galaxies
• Gaia DR2 Proper Motions of Dwarf Galaxies within 420 kpc: Orbits, Milky Way Mass, Tidal Influences, Planar Alignments, and Group Infall
• There is No Missing Satellites Problem
• Milky Way Satellite Census. II. Galaxy--Halo Connection Constraints Including the Impact of the Large Magellanic Cloud
• A MegaCam Survey of Outer Halo Satellites. III. Photometric and Structural Parameters
• The hidden giant: discovery of an enormous Galactic dwarf satellite in Gaia DR2
• The large-scale structure of the halo of the Andromeda galaxy II. Hierarchical structure in the Pan-Andromeda Archaeological Survey
• The Orbital Histories of Magellanic Satellites Using Gaia DR2 Proper Motions
• Milky Way Satellite Census. I. The Observational Selection Function for Milky Way Satellites in DES Y3 and Pan-STARRS DR1
• The upper bound on the lowest mass halo
• A Magellanic Origin of the DES Dwarfs
• Gravitational probes of dark matter physics
• Farthest Neighbor: The Distant Milky Way Satellite Eridanus II
• Gaia early DR3 systemic motions of Local Group dwarf galaxies and orbital properties with a massive Large Magellanic Cloud
• Ultra-faint dwarfs in a Milky Way context: Introducing the Mint Condition DC Justice League Simulations
• From galactic bars to the Hubble tension: weighing up the astrophysical evidence for Milgromian gravity
• The Missing Satellites of the Magellanic Clouds? Gaia Proper Motions of the Recently Discovered Ultra-Faint Galaxies
• The Gas Content and Stripping of Local Group Dwarf Galaxies
• NIHAO XV: The environmental impact of the host galaxy on galactic satellite and field dwarf galaxies
• The total satellite population of the Milky Way
• Extending the Globular Cluster System-Halo Mass Relation to the Lowest Galaxy Masses
• Discovery of two neighboring satellites in the Carina constellation with MagLiteS
• The Formation of Ultra-Diffuse Galaxies in Clusters
• Crater 2: An Extremely Cold Dark Matter Halo
• A profile in FIRE: resolving the radial distributions of satellite galaxies in the Local Group with simulations
• Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies
• Joint constraints on thermal relic dark matter from strong gravitational lensing, the Lyman-$\alpha$ forest, and Milky Way satellites
• Deep imaging of Eridanus II and its lone star cluster
• Systematics in virial mass estimators for pressure-supported systems
• At the survey limits: discovery of the Aquarius 2 dwarf galaxy in the VST ATLAS and the SDSS data
• Snake in the Clouds: A new nearby dwarf galaxy in the Magellanic bridge
• Too Big To Fail in Light of Gaia
• Limit on the LMC mass from a census of its satellites
• Nearest Neighbor: The Low-Mass Milky Way Satellite Tucana III
• The KBC void and Hubble tension contradict $\Lambda$CDM on a Gpc scale $-$ Milgromian dynamics as a possible solution
• Tidal stripping and the structure of dwarf galaxies in the Local Group
• The faint end of the Centaurus A satellite luminosity function
• First results from the MADCASH Survey: A Faint Dwarf Galaxy Companion to the Low Mass Spiral Galaxy NGC 2403 at 3.2 Mpc
• Can tides disrupt cold dark matter subhaloes?
• Identifying true satellites of the Magellanic Clouds
• Mapping substructure in the HST Frontier Fields cluster lenses and in cosmological simulations
• An Ultra-Faint Galaxy Candidate Discovered in Early Data from the Magellanic Satellites Survey
• Kinematics of Antlia 2 and Crater 2 from The Southern Stellar Stream Spectroscopic Survey (S5)
• Dark matters on the scale of galaxies
• The M101 Satellite Luminosity Function and the Halo to Halo Scatter Among Local Volume Hosts
• The Dragonfly Nearby Galaxies Survey. III. The Luminosity Function of the M101 Group
• Proper motions of Milky Way Ultra-Faint satellites with $Gaia$ DR2 $\times$ DES DR1
• The predicted luminous satellite populations around SMC and LMC-mass galaxies - A missing satellite problem around the LMC?
• Discovery of diffuse dwarf galaxy candidates around M101
• Planes of satellites around Milky Way/M31-mass galaxies in the FIRE simulations and comparisons with the Local Group
• Diversity in density profiles of self-interacting dark matter satellite halos
• The abundance of satellites around Milky Way- and M31-like galaxies with the TNG50 simulation: a matter of diversity
• Scaling Relations for Dark Matter Annihilation and Decay Profiles in Dwarf Spheroidal Galaxies
• Core-collapse, evaporation and tidal effects: the life story of a self-interacting dark matter subhalo
• Dwarf Galaxies in CDM, WDM, and SIDM: Disentangling Baryons and Dark Matter Physics
• Birds of a Feather? Magellan/IMACS Spectroscopy of the Ultra-Faint Satellites Grus II, Tucana IV, and Tucana V
• MOND and the dynamics of NGC1052-DF2
• The multiplicity and anisotropy of galactic satellite accretion
• Gaia 1 and 2. A pair of new Galactic star clusters
• Reconciling mass-estimates of ultra-diffuse galaxies
• The distribution and morphologies of Fornax Cluster dwarf galaxies suggest they lack dark matter
• Constraining the Milky Way Mass Profile with Phase-Space Distribution of Satellite Galaxies
• Strong Dark Matter Self-interactions Diversify Halo Populations within and surrounding the Milky Way
• Ghostly Galaxies as Solitons of Bose-Einstein Dark Matter
• An observer's guide to the (Local Group) dwarf galaxies: predictions for their own dwarf satellite populations
• Hunting Faint Dwarf Galaxies in the Field Using Integrated Light Surveys
• Andromeda XXI -- a dwarf galaxy in a low density dark matter halo
• Tidal disruption of dwarf spheroidal galaxies: the strange case of Crater II
• Dwarf galaxies in the MATLAS survey: Hubble Space Telescope observations of the globular cluster system in the ultra-diffuse galaxy MATLAS-2019
• Can cosmological simulations capture the diverse satellite populations of observed Milky Way analogues?
• On the nature of ultra-faint dwarf galaxy candidates I: DES1, Eridanus III and Tucana V
• Search for RR Lyrae stars in DES ultra-faint systems: Grus I, Kim 2, Phoenix II, and Grus II
• Portrait of a Dark Horse: a Photometric and Spectroscopic Study of the Ultra-faint Milky Way Satellite Pegasus III
• Star Formation Histories of Ultra-Faint Dwarf Galaxies: environmental differences between Magellanic and non-Magellanic satellites?
• Structure and kinematics of tidally limited satellite galaxies in LCDM
• MOND Prediction for the Velocity Dispersion of the `Feeble Giant' Crater II
• A Gaia DR 2 and VLT/FLAMES search for new satellites of the LMC
• Dynamical Evidence of a Solitonic Core of $10^9{M}_{\odot }$ in the Milky Way
• Discovery of an Ultra-Faint Stellar System near the Magellanic Clouds with the DECam Local Volume Exploration (DELVE) Survey
• A multi-epoch kinematic study of the remote dwarf spheroidal galaxy Leo II
• Nine tiny star clusters in Gaia DR1, PS1 and DES
• Dynamical evidence for a strong tidal interaction between the Milky Way and its satellite, Leo V
• The Role of Baryons in Creating Statistically Significant Planes of Satellites around Milky Way-Mass Galaxies
• Deep Subaru Hyper Suprime-Cam observations of Milky Way satellites Columba I and Triangulum II
• Dynamical Histories of the Crater II and Hercules Dwarf Galaxies
• The velocity anisotropy of the Milky Way satellite system
• Euclid: Early Release Observations -- Dwarf galaxies in the Perseus galaxy cluster
• The infall of dwarf satellite galaxies are influenced by their host's massive accretions
• Effective $J$-factors for Milky Way dwarf spheroidal galaxies with velocity-dependent annihilation
• Proper Motion of the Leo II Dwarf Galaxy Based On Hubble Space Telescope Imaging
• Predicted MOND velocity dispersions for a catalog of ultra-diffuse galaxies in group environments
• Revealing the Complicated Story of the Cetus Stream with StarGO
• A Plane of High Velocity Galaxies Across the Local Group
• Hubble Space Telescope Observations of Two Faint Dwarf Satellites of Nearby LMC Analogs from MADCASH
• Bootes III is a disrupting dwarf galaxy associated with the Styx stellar stream
• Discovery of the Magellanic Stellar Stream Out to 100 Kiloparsecs
• SMASH 1: a very faint globular cluster disrupting in the outer reaches of the LMC?
• A DECam View of the Diffuse Dwarf Galaxy Crater II: Variable Stars
• Stellar Density Profiles of Dwarf Spheroidal Galaxies
• Solo dwarfs II: The stellar structure of isolated Local Group dwarf galaxies
• The importance of preventive feedback: inference from observations of the stellar masses and metallicities of Milky Way dwarf galaxies
• Pegasus V -- a newly discovered ultra-faint dwarf galaxy on the outskirts of Andromeda
• Search for globular clusters associated with the Milky Way dwarf galaxies using Gaia DR2
• To the Galactic Virial Radius with Hyper Suprime-Cam
• Probing the boundary between star clusters and dwarf galaxies: A MUSE view on the dynamics of Crater/Laevens I
• Discovery of a new Local Group Dwarf Galaxy Candidate in UNIONS: Boötes V
• The missing dwarf galaxies of the Local Group
• A MegaCam Survey of Outer Halo Satellites. I. Description of the Survey
• The effect of tides on the Sculptor dwarf spheroidal galaxy
• Are Some Milky Way Globular Clusters Hosted by Undiscovered Galaxies?
• The connection between the host halo and the satellite galaxies of the Milky Way
• Precision distances to dwarf galaxies and globular clusters from Pan-STARRS1 3$\pi$ RR Lyrae
• An updated detailed characterization of planes of satellites in the MW and M31
• Identification of RR Lyrae stars in multiband, sparsely-sampled data from the Dark Energy Survey using template fitting and Random Forest classification
• Quenching in Cosmic Sheets: Tracing the Impact of Large Scale Structure Collapse on the Evolution of Dwarf Galaxies
• Deep SOAR follow-up photometry of two Milky Way outer-halo companions discovered with Dark Energy Survey
• Self-interacting dark matter interpretation of Crater II
• Variable stars in Local Group Galaxies -- V. The fast and early evolution of the low-mass Eridanus II dSph galaxy
• EDGE: The emergence of dwarf galaxy scaling relations from cosmological radiation-hydrodynamics simulations
• Proper Motion of the Sextans Dwarf Galaxy from Subaru Suprime-Cam Data
• On The Nature of ultra-faint Dwarf Galaxy Candidates II: The case of Cetus II
• Gravothermal collapse of Self-Interacting Dark Matter halos as the Origin of Intermediate Mass Black Holes in Milky Way satellites
• Spectroscopic analysis of Milky Way outer halo satellites: Aquarius II and Bootes II
• A portrait of the Vast Polar Structure as a young phenomenon: hints from its member satellites
• Tracing stars in Milky Way satellites with A-SLOTH
• A Pride of Satellites in the Constellation Leo? Discovery of the Leo VI Milky Way Satellite Galaxy with DELVE Early Data Release 3
• eRASSt J074426.3+291606: prompt accretion disc formation in a 'faint and slow' tidal disruption event
• Sizing from the Smallest Scales: The Mass of the Milky Way
• RR Lyrae Variable Stars in the Crater II Dwarf Galaxy
• Faint Satellite Population of the NGC-3175 Group - a Local Group Analogue
• The contribution of dissolving star clusters to the population of ultra-faint objects in the outer halo of the Milky Way
• Giant cold satellites from low-concentration haloes
• EDGE-INFERNO: Simulating every observable star in faint dwarf galaxies and their consequences for resolved-star photometric surveys
• All-Sky Kinematics of the Distant Halo: The Reflex Response to the LMC
• Testing the parametric model for self-interacting dark matter using matched halos in cosmological simulations
• Variable Stars in Local Group Galaxies. IV. RR Lyrae stars in the central regions of the low-density galaxy Crater II
• Micro galaxies in LCDM
• The Luminosity Functions and Redshift Evolution of Satellites of Low-Mass Galaxies in the COSMOS Survey
• A DECam View of the Diffuse Dwarf Galaxy Crater II: The Colour-Magnitude Diagram
• A MegaCam Survey of Outer Halo Satellites. VII. A Single Sérsic Index v/s Effective Radius Relation for Milky Way Outer Halo Satellites
• Galactic satellite systems in CDM, WDM and SIDM
• Satellite group infall into the Milky Way: exploring the Crater-Leo case with new HST proper motions
• Matching the mass function of Milky Way satellites in competing dark matter models
• Searching for Dark Matter Signals from Local Dwarf Spheroidal Galaxies at Low Radio Frequencies in the GLEAM Survey
• The shapes and alignments of the satellites of the Milky Way and Andromeda
• The Elusive Distance Gradient in the Ultra-Faint Dwarf Galaxy Hercules: A Combined Hubble Space Telescope and Gaia View
• The undiscovered ultra-diffuse galaxies of the Local Group
• Consequences for the Scalar Field Dark Matter model from The McGaugh Observed-Baryon Acceleration Correlation
• Ghostly Stellar Haloes and their Relationship to Ultra-faint Dwarfs
• The proper motion of stars in dwarf galaxies: distinguishing central density cusps from cores
• Anticipating the XRISM search for the decay of resonantly produced sterile neutrino dark matter
• Andromeda XXV -- a dwarf galaxy with a low central dark matter density
• Resolved Stellar Populations as Tracers of Outskirts
• Understanding the "Feeble Giant" Crater II with tidally stretched Wave Dark Matter
• Mass Modeling the Andromeda Dwarf Galaxies: Andromeda VI and Andromeda XXIII
• Exploring the Diversity of Faint Satellites in the M81 Group
• Impulsive mixing of stellar populations in dwarf spheroidal galaxies
• Destruction of the central black hole gas reservoir through head-on galaxy collisions
• Unlocking Discovery Potential for Decaying Dark Matter and Faint X-ray Sources with XRISM
• DELVE-DEEP Survey: The Faint Satellite System of NGC 55
• Densities and mass assembly histories of the Milky Way satellites are not a challenge to $\Lambda$CDM
• Gaia DR3 and nearby galaxies: where do foregrounds matter?
• DELVE Milky Way Satellite Galaxy Census I: Satellite Population and Survey Selection Function in DES, DELVE, and Pan-STARRS
• Environmental Quenching of Low Surface Brightness Galaxies near Milky Way mass Hosts
• Quantifying the Detectability of Milky Way Satellites with Image Simulations: a Case Study with KiDS
• MONDian predictions for Newtonian M/L ratios for ultrafaint dSphs
• Broken Expectations: The Effects of Modelling Assumptions on the Inferred Dark Matter Distribution in the Milky Way's Satellites
• Structural parameters and possible association of the Ultra-Faint Dwarfs Pegasus III and Pisces II from deep Hubble Space Telescope photometry
• Galactic tides and the Crater II dwarf spheroidal: a challenge to LCDM?
• Magellan/IMACS spectroscopy of Grus I: A low metallicity ultra-faint dwarf galaxy
• Zwicky Transient Facility and Globular Clusters: The RR Lyrae gri-Band Period-Luminosity-Metallicity and Period-Wesenheit-Metallicity Relations
• Near-Field Cosmology with the Lowest-Mass Galaxies