The Tidal Evolution of Local Group Dwarf Spheroidals

By J. Peñarrubia, Julio F. Navarro, A. McConnachie. 2007

294 citations recorded by the source corpus.

We use N-body simulations to study the evolution of dwarf spheroidal galaxies (dSphs) driven by galactic tides. We adopt a cosmologically motivated model where dSphs are approximated by a King model embedded within an NFW halo. We find that these NFW-embedded King models are extraordinarily resilient to tides; the stellar density profile still resembles a King model even after losing more than 99% of the stars. As tides strip the galaxy, the stellar luminosity, velocity dispersion, central surface brightness, and core radius decrease monotonically. Remarkably, we find that the evolution of these parameters is solely controlled by the total amount of mass lost from within the luminous radius. Of all parameters, the core radius is the least affected: after losing 99% of the stars, Rc decreases by just a factor of ~2. Interestingly, tides tend to make dSphs more dark matter-dominated because the tightly bound central dark matter “cusp” is more resilient to disruption than the “cored” King profile. We examine whether the extremely large mass-to-light ratios of the newly discovered ultrafaint dSphs might have been caused by tidal stripping of once-brighter systems. Although dSph tidal evolutionary tracks parallel the observed scaling relations in the luminosity-radius plane, they predict too steep a change in velocity dispersion compared with the observational estimates hitherto reported in the literature. The ultrafaint dwarfs are thus unlikely to be the tidal remnants of systems like Fornax, Draco, or Sagittarius. Despite spanning four decades in luminosity, dSphs appear to inhabit halos of comparable peak circular velocity, lending support to scenarios that envision dSphs as able to form only in halos above a certain mass threshold.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/3d1256f75347cd611c198b2778913a095b885c5e

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

Citations in the corpus

THE SAGITTARIUS DWARF GALAXY: A MODEL FOR EVOLUTION IN A TRIAXIAL MILKY WAY HALO (2010, methodology): “…in the tidal debris streams reflects the mass present within the tidal radius of Sgr on the orbit immediately prior to that debris becoming unbound (see, e.g., Johnston et al. 1996; Johnston 1998; Peñarrubia et al. 2008), it can therefore be used to constrain the mass of the dSph (e.g., LJM05).”
The Aquarius Project: the subhaloes of galactic haloes (2008, background): “This can be understood as a consequence of tidal truncation and mass loss (Kazantzidis et al., 2004; Bullock & Johnston, 2005; Peñarrubia et al., 2008) which lead to a larger reduction of Vmax than of rmax.”
The missing massive satellites of the Milky Way (2012, background): “The latter correlates strongly with the total dark mass of the dwarf, which is usually expressed in terms of its maximum circular velocity, Vmax, a quantity less affected than mass by tidal stripping (Peñarrubia et al. 2008).”
Gaia DR2 proper motions of dwarf galaxies within 420 kpc (2018, background): “We deem this latter hypothesis unlikely (see results from N-body simulations, e.g. Muñoz et al. 2008; Peñarrubia et al. 2008, for those simulated objects on similar orbits), but this is certainly an important aspect to be verified, since several of the MW dwarf galaxies are on more internal orbits…”
The hidden giant: discovery of an enormous Galactic dwarf satellite in Gaia DR2 (2018, background): “Bear in mind however that, while tides tend to lower a satellite’s density, typically (as demonstrated by Peñarrubia et al. 2008b, 2012), as the satellite loses mass to the host, it tends to shrink rather than expand.”
A KINEMATIC STUDY OF THE ANDROMEDA DWARF SPHEROIDAL SYSTEM (2013, methodology): “From a modelling point of view, one does not expect stars to be able to form within all dark matter subhalos seen in simulations, and at a certain mass limit (Vmax ∼< 15 km s −1, see Peñarrubia et al. 2008a; Koposov et al. 2009), star formation is unable to proceed.”
A METHOD FOR MEASURING (SLOPES OF) THE MASS PROFILES OF DWARF SPHEROIDAL GALAXIES (2011, background): “…component during a close pericentricpassage and/or by stripping stars that, thence unbound, linger 16 sufficiently near the dSph to be observed and counted as bound members (e.g., Piatek & Pryor 1995; Oh et al. 1995; Read et al. 2006; Klimentowski et al. 2007; Peñarrubia et al. 2008b, 2009).”
The Phoenix Project: the dark side of rich galaxy clusters (2012, methodology): “As expected for haloes that have undergone tidal stripping,rmax shifts inwards as the subhalo loses mass whilst leaving the peak velocity relativ y unchanged (Peñarrubia et al. 2008).”
SUBSTRUCTURE DEPLETION IN THE MILKY WAY HALO BY THE DISK (2009, background): “The contribution of the halo to this process has been included in previ- ous studies (Hayashi et al. 2003; Kazantzidis et al. 2004b; Read et al. 2006; Peñarrubia et al. 2008; Muñoz et al. 2008) but generally not that from the luminous galaxy (but see Taylor & Babul 2001).”
A QUANTITATIVE EXPLANATION OF THE OBSERVED POPULATION OF MILKY WAY SATELLITE GALAXIES (2009, background): “Simulations suggest that these assumptions are reasonable but not perfect approximations (Simha et al. 2008; Peñarrubia et al. 2008).”
THE STAR FORMATION HISTORIES OF LOCAL GROUP DWARF GALAXIES. I. HUBBLE SPACE TELESCOPE/WIDE FIELD PLANETARY CAMERA 2 OBSERVATIONS (2014, background): “In contrast, the lowest luminosity dSphs are thought to generally host simple stellar populations, and are among the best candidates for remnant primordial galaxies (e.g., Simon & Geha 2007; Kirby et al. 2008; Peñarrubia et al. 2008; Frebel 2010; Belokurov 2013; Walker 2013).”
THE VELOCITY WIDTH FUNCTION OF GALAXIES FROM THE 40% ALFALFA SURVEY: SHEDDING LIGHT ON THE COLD DARK MATTER OVERABUNDANCE PROBLEM (2011, background): “The same argument has been identified as a possible solution of the “mini-void size” problem by Tikhonov & Klypin (2009), while a similar effect has been proposed by Peñarrubia et al. (2008) as a solution to the “missing satellites” problem.”
A Comprehensive Maximum Likelihood Analysis of the Structural Properties of Faint Milky Way Satellites (2008, background): “Moreover, the importance of the Peñarrubia et al. (2008b) caveat depends, for each satellite, on the amount of stellar loss, which is all but constrained.”
HIGH-RESOLUTION SPECTROSCOPY OF EXTREMELY METAL-POOR STARS IN THE LEAST EVOLVED GALAXIES: URSA MAJOR II and COMA BERENICES (2009, background): “This contrast between the abundance patterns seen in high and low luminosity dwarf galaxies demonstrates again that the ultra-faint dwarfs cannot simply be tidally stripped versions of the classical dSphs (Peñarrubia et al. 2008; Kirby et al. 2008; Geha et al. 2008).”
A timing constraint on the (total) mass of the Large Magellanic Cloud (2015, background): “Given that satellite galaxies orbiting around a massive host lose a large fraction of their dark matter halo envelope to tides (e.g. Peñarrubia et al. 2008, 2009), an early accretion scenario would truncate the halo profile and limit the total mass to the mass enclosed within their luminous radius,…”
The Most Dark-Matter-dominated Galaxies: Predicted Gamma-Ray Signals from the Faintest Milky Way Dwarfs (2007, background): “These galaxies may have been tidally stripped before (for example, if their orbit took them closer to the center of theMW); however, the stellar core that has survived is faithfully tracing the local potential (Piatek & Pryor 1995; Klimentowski et al. 2007; Peñarrubia et al. 2008).”
PRE-REIONIZATION FOSSILS, ULTRA-FAINT DWARFS, AND THE MISSING GALACTIC SATELLITE PROBLEM (2008, background): “Conversely, a recent work of Peñarrubia et al. (2008) looks at tidal stripping of dark matter and stars, achieving some success in reproducing the observed properties of ultra-faint dwarfs assuming that they are tidally stripped dIrrs.”