Tidal Stirring and the Origin of Dwarf Spheroidals in the Local Group

By Lucio Mayer, Fabio Governato, M. Colpi, B. Moore, Thomas R. Quinn, James Wadsley, Joachim Stadel, George Lake. 2000

205 citations recorded by the source corpus.

N-body + smoothed particle hydrodynamics (SPH) simulations are used to study the evolution of dwarf irregular galaxies (dIrr's) entering the dark matter halo of the Milky Way or M31 on plunging orbits. We propose a new dynamical mechanism driving the evolution of gas-rich, rotationally supported dIrr's, mostly found at the outskirts of the Local Group (LG), into gas-free, pressure-supported dwarf spheroidals (dSph's) or dwarf ellipticals (dE's), observed to cluster around the two giant spirals. The initial model galaxies are exponential disks embedded in massive dark matter halos and reproduce nearby dIrr's. Repeated tidal shocks at the pericenters of their orbits partially strip their halos and disks and trigger dynamical instabilities that dramatically reshape their stellar components. After only 2-3 orbits low surface brightness dIrr's are transformed into dSp'hs while high surface brightness dIrr's evolve into dE's. This evolutionary mechanism naturally leads to the morphology-density relation observed for LG dwarfs. Dwarfs surrounded by very dense dark matter halos, such as the dIrr GR8, are turned into Draco or Ursa Minor, the faintest and most dark matter dominated among LG dSph's. If disks include a gaseous component, this is both tidally stripped and consumed in periodic bursts of star formation. The resulting star formation histories are in good qualitative agreement with those derived using Hubble Space Telescope (HST) color-magnitude diagrams for local dSph's.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/ce902036f8626677280e1d65196bfa892478e7c9

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Citations in the corpus

Formation and Evolution of Galaxy Dark Matter Halos and Their Substructure (2007, background): “All halos except one undergo pericenter passages that can lead to tidally induced changes in galaxy morphologies (Mayer et al. 2001a,b).”
A UNIVERSAL MASS PROFILE FOR DWARF SPHEROIDAL GALAXIES? (2009, methodology): “While Klimentowski et al. (2007) succesfully test their algorithm and mass estimator using an N-body simulation of a tidally “stirred” (Mayer et al. 2001a,b) satellite in which mass actually does follow light (after 99% of the initial dark mass is stripped), they do not demonstrate that their…”
Mass loss from dwarf spheroidal galaxies: the origins of shallow dark matter cores and exponential surface brightness profiles (2004, background): “…1974; Dekel & Silk 1986; Efstathiou 2000; Dekel & Woo 2003); photoevaporation (Quinn, Katz & Efstathiou 1996; Barkana & Loeb 1999); and the effects of galaxy harassment and tidal stripping from a large host galaxy (Moore et al. 1996; Moore, Lake & Katz 1998; Mayer et al. 2001; Hayashi et al. 2003).”
A REVISED PARALLEL-SEQUENCE MORPHOLOGICAL CLASSIFICATION OF GALAXIES: STRUCTURE AND FORMATION OF S0 AND SPHEROIDAL GALAXIES (2011, background): “A variant in the Local Group is tidal stirring of dwarfs on very elliptical orbits by the Galaxy or M31 (Mayer et al. 2001a,b, 2006) Harassment is suggested to convert flimsy, late-type disks into spheroidals and more robust, earlier-type spirals into much hotter systems that resemble S0s in many…”
THE UNIVERSAL STELLAR MASS–STELLAR METALLICITY RELATION FOR DWARF GALAXIES (2013, background): “In the absence of inflowing gas, the gas fraction is depleted by the outflow rate (E) and the SFR. dg dt =−E − ds dt (10) 11 Tidal stripping or ram pressure stripping in conjunction with tidal stripping (Mayer et al. 2001) can also remove gas.”
Virgo Cluster Early-Type Dwarf Galaxies with the Sloan Digital Sky Survey. II. Early-Type Dwarfs with Central Star Formation (2006, background): “While galaxy harassment is negligible in groups (Mayer et al. 2001b), a similar mechanism is provided there by the so-called tidal stirring scenario (Mayer et al. 2001a), in which a dIrr that suffers repeated tidal shocks is transformed into a dE or a dSph.”
On the life and death of satellite haloes (2003, methodology): “Alternatively, they could have entered the halo at fairly high redshift, which would place them naturally on an inner, tightly bound orbit (Mayer et al. 2001b).”
THE ACS NEARBY GALAXY SURVEY TREASURY. VIII. THE GLOBAL STAR FORMATION HISTORIES OF 60 DWARF GALAXIES IN THE LOCAL VOLUME (2011, background): “Instead, Mayer et al. (2001a, 2006) advocate a more complex approach in which a combination of ram pressure stripping and stellar mass loss due to tidal effects provide a plausible model, ‘tidal stirring’, for the transformation of gas-rich dIs into gas-poor dSphs.”
Highly Ionized High-Velocity Gas in the Vicinity of the Galaxy (2002, background): “Tidal interactions of the fragments and galaxies in the Local Group could drive dynamical instabilities in some of the smaller galaxies and strip interstellar material from gas-rich irregular galaxies (Mayer et al. 2001).”
Galaxy formation theory (2010, background): “The generic results of such heating are to cause the galaxy to expand and to destroy cold, ordered structures such as disks (Mooreet al. 1996b, 1998; Mayer et al. 2001a,b; Gnedin 2003; Mastropietro et al. 2005a,b).”
Population Gradients in Local Group Dwarf Spheroidal Galaxies (2001, background): “The driver of the gradient could be the gravitational potential of the dSph, which would either retain the star-forming gas longer in its central regions or retain both the gas and newly formed metals (Mayer et al. 2001).”
The importance of tides for the Local Group dwarf spheroidals (2005, methodology): “We argue in this paper that the Local Group dSphs have not been significantly stripped interior to 1 kpc, but this need not invalidate the tidal transformation model proposed by Mayer et al. (2001a).”
The Metamorphosis of Tidally Stirred Dwarf Galaxies (2001, methodology): “As shown in Mayer et al. (2001), it is possible to construct the fundamental plane for the remnants coupling the information directly provided by the simulations with the model for the photometric evolution described in this section.”
The Velocity Dispersion Profile of the Remote Dwarf Spheroidal Galaxy Leo I: A Tidal Hit and Run? (2007, methodology): “This behavior is reflected in some of the models of Mayer et al. (2001a, 2001b, 2006) although these authors did not explore orbits quite as eccentric as we are considering for Leo I.”
Dark matter cores all the way down (2015, background): “Secondly, while surviving dwarfs may be on relatively benign orbits, their dark matter cores can still play a role in facilitating their transformation from dwarf irregulars to dwarf spheroidals (Mayer et al. 2001; Lokas et al. 2012; Kazantzidis et al. 2013).”
Feedback and metal enrichment in cosmological SPH simulations – II. A multiphase model with supernova energy feedback (2006, background): “…simulations assuming different types of initial conditions have also found such bursty behaviour for the star formation activity in small mass systems (e.g. Steinmetz & Navarro 1999; Carraro et al. 2001; Mayer et al. 2001; Pearce et al. 2001; Chiosi & Carraro 2002; Springel & Hernquist 2003).”
The Progenitors of Dwarf Spheroidal Galaxies (2002, background): “For cases where cessation of star formation also is associated with loss of stars, e.g., in cases of tidal stripping, an even larger decline in surface brightness should occur (e.g., Mayer et al. 2001a).”
Simultaneous ram pressure and tidal stripping; how dwarf spheroidals lost their gas (2005, methodology): “For the gas densities (∼10−4 atoms cm−3) and velocities occurring at pericenter, the time-scale for KH stripping is, respectively, 4 Gyr for model V40c20 and 10 Gyr for model V60c4, these being the model galaxies in which instantaneous ram pressure is not capable of removing all the gas.”