Segue 2 Recently Collided with the Cetus-Palca Stream: New Opportunities to Constrain Dark Matter in an Ultra-Faint Dwarf

Abstract

Stellar streams in the Milky Way are promising detectors of low-mass dark matter (DM) subhalos predicted by $\Lambda$CDM. Passing subhalos induce perturbations in streams that indicate the presence of the subhalos. Understanding how known DM-dominated satellites impact streams is a crucial step towards using stream perturbations to constrain the properties of dark perturbers. Here, we cross-match a \textit{Gaia} EDR3 and SEGUE member catalog of the Cetus-Palca stream (CPS) with H3 for additional radial velocity measurements and fit the orbit of the CPS using this 6-D data. We demonstrate for the first time that the ultra-faint dwarf Segue 2 had a recent (77$\pm$5 Myr ago) close flyby (within the stream's 2$\sigma$ width) with the CPS. This interaction enables constraints on Segue 2's mass and density profile at larger radii ($\mathcal{O}(1)$ kpc) than are probed by its stars ($\mathcal{O}(10)$ pc). While Segue 2 is not expected to strongly affect the portion of the stream covered by our 6-D data, we predict that if Segue 2's mass within $\sim 6$ kpc is $5\times 10^9{M}_{\odot }$, the CPS's velocity dispersion will be $\sim 40$ km s${}^{-1}$ larger at ${\varphi }_1>20^{\circ }$ than at ${\varphi }_1<0^{\circ }$. If no such heating is detected, Segue 2's mass cannot exceed $10^9{M}_{\odot }$ within $\sim 6$ kpc. The proper motion distribution of the CPS near the impact site is mildly sensitive to the shape of Segue 2's density profile. This study presents a critical test for frameworks designed to constrain properties of dark subhalos from stream perturbations.

arXiv comment33 pages, 14 figures, 6 tables. Updated for consistency with published version

References in corpus (161)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• The Structure of Cold Dark Matter Halos
• The Gaia mission
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• Statistical Properties of X-ray Clusters: Analytic and Numerical Comparisons
• Observational evidence for self-interacting cold dark matter
• MESA Isochrones and Stellar Tracks (MIST) 0: Methods for the construction of stellar isochrones
• Local Kinematics and the Local Standard of Rest
• Cold and Fuzzy Dark Matter
• Small-Scale Challenges to the $\Lambda$CDM Paradigm
• SEGUE: A Spectroscopic Survey of 240,000 stars with g=14-20
• Dark Matter Self-interactions and Small Scale Structure
• Cosmic Structure as the Quantum Interference of a Coherent Dark Wave
• The Diversity and Similarity of Simulated Cold Dark Matter Halos
• How supernova feedback turns dark matter cusps into cores
• Observational and Theoretical Constraints on Singular Dark Matter Halos
• The Core-Cusp Problem
• Mass models of the Milky Way
• Cosmological Simulations with Self-Interacting Dark Matter I: Constant Density Cores and Substructure
• Extragalactic Science, Cosmology and Galactic Archaeology with the Subaru Prime Focus Spectrograph (PFS)
• A distance to the Large Magellanic Cloud that is precise to one per cent
• The Cores of Dwarf Galaxy Halos
• Subhaloes in Self-Interacting Galactic Dark Matter Haloes
• The Faintest Dwarf Galaxies
• The dependence of dark matter profiles on the stellar to halo mass ratio: a prediction for cusps vs cores
• Third-Epoch Magellanic Cloud Proper Motions I: HST/WFC3 data and Orbit Implications
• Cusp-core transformations in dwarf galaxies: observational predictions
• Mass loss from dwarf spheroidal galaxies: the origins of shallow dark matter cores and exponential surface brightness profiles
• Stellar Feedback in Dwarf Galaxy Formation
• The Impact of Baryonic Physics on the Structure of Dark Matter Halos: the View from the FIRE Cosmological Simulations
• The total mass of the Large Magellanic Cloud from its perturbation on the Orphan stream
• NIHAO IV: Core creation and destruction in dark matter density profiles across cosmic time
• 4MOST: Project overview and information for the First Call for Proposals
• The distribution of dark matter in galaxies
• The Milky Way stellar halo out to 40 kpc : Squashed, broken but smooth
• Tango for three: Sagittarius, LMC, and the Milky Way
• Stellar Streams Discovered in the Dark Energy Survey
• Weakly Self-Interacting Dark Matter and the Structure of Dark Halos
• Axion dark matter, solitons, and the cusp-core problem
• The M31 Velocity Vector. II. Radial Orbit Towards the Milky Way and Implied Local Group Mass
• Uncovering CDM halo substructure with tidal streams
• FIRE in the Field: Simulating the Threshold of Galaxy Formation
• Dwarf galaxies in CDM and SIDM with baryons: observational probes of the nature of dark matter
• There is No Missing Satellites Problem
• How Lumpy is the Milky Way's Dark Matter Halo?
• Segue 2: A Prototype of the Population of Satellites of Satellites
• The wide-field, multiplexed, spectroscopic facility WEAVE: Survey design, overview, and simulated implementation
• Milky Way Satellite Census. II. Galaxy--Halo Connection Constraints Including the Impact of the Large Magellanic Cloud
• Hunting for the Dark Matter Wake Induced by the Large Magellanic Cloud
• The Spur and the Gap in GD-1: Dynamical evidence for a dark substructure in the Milky Way halo
• Maximum Feedback and Dark Matter Profiles of Dwarf Galaxies
• Clumpy Streams from Clumpy Halos: Detecting Missing Satellites with Cold Stellar Structures
• The Orbital Histories of Magellanic Satellites Using Gaia DR2 Proper Motions
• And yet it moves: The dangers of artificially fixing the Milky Way center of mass in the presence of a massive Large Magellanic Cloud
• Tidal Tails of Star Clusters
• The upper bound on the lowest mass halo
• Sweating the small stuff: simulating dwarf galaxies, ultra-faint dwarf galaxies, and their own tiny satellites
• More on the structure of tidal tails
• Charting the Galactic acceleration field I. A search for stellar streams with Gaia DR2 and EDR3 with follow-up from ESPaDOnS and UVES
• The chosen few: the low mass halos that host faint galaxies
• A dark matter profile to model diverse feedback-induced core sizes of $\Lambda$CDM haloes
• The Baryon Cycle of Dwarf Galaxies: Dark, Bursty, Gas-Rich Polluters
• Mapping the Stellar Halo with the H3 Spectroscopic Survey
• Segue 2: The Least Massive Galaxy
• Overview of the DESI Milky Way Survey
• Constraints on the shape of the Milky Way dark matter halo from the Sagittarius stream
• Response of the Milky Way's disc to the Large Magellanic Cloud in a first infall scenario
• Discovery of a New, Polar-Orbiting Debris Stream in the Milky Way Stellar Halo
• Non-circular motions and the diversity of dwarf galaxy rotation curves
• Connecting the first galaxies with ultra faint dwarfs in the Local Group: chemical signatures of Population~III stars
• A sharper view of Pal 5's tails: Discovery of stream perturbations with a novel non-parametric technique
• The case for a cold dark matter cusp in Draco
• Ultra-Light Dark Matter in Ultra-Faint Dwarf Galaxies
• Jeans Analysis for Dwarf Spheroidal Galaxies in Wave Dark Matter
• Piercing the Milky Way: an all-sky view of the Orphan Stream
• On the structure of tidal tails
• Orbits of Massive Satellite Galaxies: I. A Close Look at the Large Magellanic Cloud and a New Orbital History for M33
• Off the beaten path: Gaia reveals GD-1 stars outside of the main stream
• Quantifying the impact of the Large Magellanic Cloud on the structure of the Milky Way's dark matter halo using Basis Function Expansions
• Tracing Sagittarius Structure with SDSS and SEGUE Imaging and Spectroscopy
• Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies
• Measuring the Mass of the Large Magellanic Cloud with Stellar Streams Observed by $S^5$
• Forensics of Subhalo-Stream Encounters: The Three Phases of Gap Growth
• Baryonic clues to the puzzling diversity of dwarf galaxy rotation curves
• Unbiased constraints on ultralight axion mass from dwarf spheroidal galaxies
• Detection of the Milky Way reflex motion due to the Large Magellanic Cloud infall
• Stream-orbit misalignment I: The dangers of orbit-fitting
• The Preferential Tidal Stripping of Dark Matter versus Stars in Galaxies
• Properties of Dark Subhaloes from Gaps in Tidal Streams
• The mechanics of tidal streams
• $S^5$: Probing the Milky Way and Magellanic Clouds potentials with the 6-D map of the Orphan-Chenab stream
• Star Stream Folding by Dark Galactic Sub-Halos
• NIHAO IX: the role of gas inflows and outflows in driving the contraction and expansion of cold dark matter haloes
• Detection of the LMC-induced sloshing of the Galactic halo
• galstreams: A Library of Milky Way Stellar Stream Footprints and Tracks
• Diversity of dark matter density profiles in the Galactic dwarf spheroidal satellites
• Kinematics of Antlia 2 and Crater 2 from The Southern Stellar Stream Spectroscopic Survey (S5)
• Revised and new proper motions for confirmed and candidate Milky Way dwarf galaxies
• The Pal 5 Star Stream Gaps
• The PAndAS Field of Streams: stellar structures in the Milky Way halo toward Andromeda and Triangulum
• $S^5$: The Orbital and Chemical Properties of One Dozen Stellar Streams
• A Cold Milky Way Stellar Stream in the Direction of Triangulum
• The core-cusp problem: a matter of perspective
• Quantifying scatter in galaxy formation at the lowest masses
• Ultra-light Dark Matter is Incompatible with the Milky Way's Dwarf Satellites
• Going, going, gone dark: Quantifying the scatter in the faintest dwarf galaxies
• Orbital Clustering Identifies the Origins of Galactic Stellar Streams
• Quantitative analysis of clumps in the tidal tails of star clusters
• Stream-orbit misalignment II: A new algorithm to constrain the Galactic potential
• Reflex motion in the Milky Way stellar halo resulting from the Large Magellanic Cloud infall
• Ultrafaint Dwarf Galaxies - the lowest mass relics from before reionization
• Production of Milky Way structure by the Magellanic Clouds
• Proper Motions of Stellar Streams Discovered in the Dark Energy Survey
• The effect of the LMC on the Milky Way system
• Dynamics of stream-subhalo interactions
• Equilibrium models of the Milky Way mass are biased high by the LMC
• Broken into Pieces: ATLAS and Aliqa Uma as One Single Stream
• Modelling the Tucana III stream - a close passage with the LMC
• The effect of the deforming dark matter haloes of the Milky Way and the Large Magellanic Cloud on the Orphan-Chenab stream
• MINESweeper: Spectrophotometric Modeling of Stars in the Gaia Era
• Signatures of LCDM substructure in tidal debris
• Dynamical models for the Sculptor dwarf spheroidal in a Lambda CDM universe
• Quantifying the Stellar Halo's Response to the LMC's Infall with Spherical Harmonics
• Butterfly in a Cocoon, Understanding the origin and morphology of Globular Cluster Streams: The case of GD-1
• The Dynamics of Star Stream Gaps
• Probing the nature of dark matter with accreted globular cluster streams
• High-resolution spectroscopy of the GD-1 stellar stream localizes the perturber near the orbital plane of Sagittarius
• Locating the orbits delineated by tidal streams
• Globular Clusters in a Cosmological N-body Simulation
• Multiple components of the Jhelum stellar stream
• The role of faint population III supernovae in forming CEMP stars in ultra-faint dwarf galaxies
• The diversity of rotation curves of simulated galaxies with cusps and cores
• The Complexity of the Cetus Stream Unveiled from the Fusion of STREAMFINDER and StarGO
• Kinematic Discovery of a Stellar Stream located in Pisces
• Degeneracies Between Self-interacting Dark Matter and Supernova Feedback as cusp-core transformation mechanisms
• Simulating tidal streams in a high resolution dark matter halo
• Revealing the Complicated Story of the Cetus Stream with StarGO
• Is NGC 5824 the Core of the Progenitor of the Cetus Stream?
• Dispersal of tidal debris in a Milky-Way-sized dark matter halo
• The many reasons that the rotation curves of low-mass galaxies can fail as tracers of their matter distributions
• Clumpy streams in a smooth dark halo: the case of Palomar 5
• Highly r-process enhanced stars in ultra-faint dwarf galaxies
• The Cetus-Palca stream: A disrupted small dwarf galaxy. A prequel to the science possible with WEAVE with precise spectro-photometric distances
• The impact of cored density profiles on the observable quantities of dwarf spheroidal galaxies
• Update on the Cetus Polar Stream and its Progenitor
• The Effects of Dwarf Galaxies on the Orbital Evolution of Galactic Globular Clusters
• The nature of core formation in dark matter haloes: adiabatic or impulsive?
• Quantifying tidal stream disruption in a simulated Milky Way
• HSTPROMO Internal Proper Motion Kinematics of Dwarf Spheroidal Galaxies: I. Velocity Anisotropy and Dark Matter Cusp Slope of Draco
• Real and counterfeit cores: how feedback expands halos and disrupts tracers of inner gravitational potential in dwarf galaxies
• SN-driven mechanism of cusp-core transformation: an appraisal
• Probability of forming gaps in the GD-1 stream by close encounters of globular clusters
• The time evolution of gaps in tidal streams
• The LMC impact on the kinematics of the Milky Way satellites: clues from the running solar apex
• Characterization and dynamics of the peculiar stream Jhelum, A tentative role for the Sagittarius dwarf galaxy
• Probing the assembly of dwarf galaxies through cosmic time with damped Lyman-$\alpha$ absorption spectroscopy
• Time evolution of gaps in stellar streams in axisymmetric Stäckel potentials

Cited by in corpus (1)

• Inferring the density and membership of stellar streams with flexible models: The GD-1 stream in Gaia Data Release 3