Cusp-core transformations in dwarf galaxies: observational predictions

By Romain Teyssier, Andrew Pontzen, Y. Dubois, Justin I. Read. 2012

343 citations recorded by the source corpus.

The presence of a dark matter core in the central kiloparsec of many dwarf galaxies has been a long standing problem in galaxy formation theories based on the standard cold dark matter paradigm. Recent simulations, based on Smooth Particle Hydrodynamics and rather strong feedback recipes have shown that it was indeed possible to form extended dark matter cores using baryonic processes related to a more realistic treatment of the interstellar medium. Using adaptive mesh renement, together with a new, stronger supernovae feedback scheme that we have recently implemented in the RAMSES code, we show that it is also possible to form a prominent dark matter core within the well-controlled framework of an isolated, initially cuspy, 10 billion solar masses dark matter halo. Although our numerical experiment is idealized, it allows a clean and unambiguous identication of the dark matter core formation process. Our dark matter inner prole is well tted by a pseudo-isothermal prole with a core radius of 800 pc. The core formation mechanism is consistent with the one proposed recently by Pontzen & Governato. We highlight two key observational predictions of all simulations that nd cusp-core transformations: (i) a bursty star formation history (SFH) with peak to trough ratio of 5 to 10 and a duty cycle comparable to the local dynamical time; and (ii) a stellar distribution that is hot with v= 1. We compare the observational properties of our model galaxy with recent measurements of the isolated dwarf WLM. We show that the spatial and kinematical distribution of stars and HI gas are in striking agreement with observations, supporting the fundamental role played by stellar feedback in shaping both the stellar and dark matter distribution.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/93ab4305688f139534487872ac546d7348889d67

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In Astronomy and Astrophysics

1. P. Hopkins
2. L. Hernquist
3. Volker Springel
4. R. Dav'e
5. C. Faucher-Giguére
6. A. Dekel
7. T. Naab
8. D. Keres̆

Citations in the corpus

• Dark matter annihilation and decay in dwarf spheroidal galaxies: the classical and ultrafaint dSphs (2015, background): “This can be surprisingly effective even for low stellar mass systems (e.g. Navarro, Eke & Frenk 1996; Read & Gilmore 2005; Pontzen & Governato 2012; Teyssier et al. 2013; Madau, Shen & Governato 2014; Oñorbe et al. 2015).”
• Three-phase Interstellar Medium in Galaxies Resolving Evolution with Star Formation and Supernova Feedback (TIGRESS): Algorithms, Fiducial Model, and Convergence (2016, methodology): “To deal with the “overcooling” problem in galaxy formation simulations, a wide variety of sub-grid models for treating feedback has been developed (e.g., Dalla Vecchia & Schaye 2012; Agertz et al. 2013; Teyssier et al. 2013; Hopkins et al. 2014; Kimm & Cen 2014).”
• Understanding the shape and diversity of dwarf galaxy rotation curves in ΛCDM (2016, background): “…been observed in high resolution hydrodynamic simulations that resolve the interstellar medium (e.g. Mashchenko et al. 2008; Governato et al. 2010; Teyssier et al. 2013; Di Cintio et al. 2014; Trujillo-Gomez et al. 2015; Oñorbe et al. 2015; Read et al. 2016; and for a review see Pontzen &…”
• FIRE-2 simulations: physics versus numerics in galaxy formation (2017, background): “By “turning off cooling” for some adjusted duration, as in Stinson et al. (2006); Governato et al. (2010); Macciò et al. (2012); Teyssier et al. (2013); Stinson et al. (2013); Crain et al. (2015), or directly putting in winds “by hand” as in Springel & Hernquist (2003a); Davé et al. (2006);…”
• Theoretical Challenges in Galaxy Formation (2016, background): “The gas cooling is also delayed in ’non-thermal’ heating models (Teyssier et al. 2013).”
• Small scale problems of the $\Lambda$CDM model: a short review (2016, methodology): “[289] used the adaptive mesh refinement code RAMSES together with a new SN feedback scheme, finding results in agreement with [296] (see Figure 7, bottom left panel), which showed that M∗ > 107M galaxies have a flat inner profile.”
• ESCAPE FRACTION OF IONIZING PHOTONS DURING REIONIZATION: EFFECTS DUE TO SUPERNOVA FEEDBACK AND RUNAWAY OB STARS (2014, background): “…with the ambient medium (Oppenheimer & Davé 2006), turning off gas cooling after deposition of SN energy for a significant period of time (Mori et al. 1997; Stinson et al. 2006; Governato et al. 2007), or disabling cooling when the turbulence measured locally is significant (Teyssier et al. 2013).”
• NIHAO - XI. Formation of ultra-diffuse galaxies by outflows (2016, background): “…cause expansion not only of the central DM distribution in galaxies (e.g. Governato et al. 2010; Di Cintio et al. 2014a,b; Oñorbe et al. 2015; Tollet et al. 2016; Chan et al. 2015; Read et al. 2016), but also of the stellar one (e.g. Teyssier et al. 2013; ElBadry et al. 2016; Dutton et al. 2016).”
• (Star)bursts of FIRE: observational signatures of bursty star formation in galaxies (2015, result): “In contrast, several recent simulations have attempted to physically model the effects of feedback on star-forming clouds instead of imposing a sub-resolution description of them (Stinson et al. 2006; Mashchenko et al. 2008; Governato et al. 2010; Zolotov et al. 2012; Teyssier et al. 2013).”
• Forged in FIRE: cusps, cores and baryons in low-mass dwarf galaxies (2015, background): “…the energy requirements for the formation of a core in a dwarf galaxy halo (see, for example Peñarrubia et al. 2012; Garrison-Kimmel et al. 2013; Teyssier et al. 2013, and references therein) – specifically, how many stars are required for there to be enough energy available to create a core?”
• The cosmic evolution of massive black holes in the Horizon-AGN simulation (2016, background): “Dubois et al. (2015) find that strong SN feedback (using a ‘delayed cooling’ prescription from Teyssier et al. 2013) in low-mass galaxies (or haloes) is able to limit BH growth by SN-driven outflows, which deplete the central region of the galaxy of gas.”
• Dwarf galaxies in CDM and SIDM with baryons: observational probes of the nature of dark matter (2014, methodology): “This seems to indicate that SNe-driven outflows can only act as a solution to this problem if they occur very early, when the halo progenitors of present-day dwarfs were less massive (Teyssier et al. 2013; Amorisco et al. 2014).”
• The local dark matter density (2014, background): “…Hopkins et al., 2013), though at present rather strong feedback – where a significant fraction of the available SNe energy couples very efficiently to the surrounding gas – appears to be required (e.g. Mashchenko et al., 2008; Governato et al., 2010; Guedes et al., 2011; Teyssier et al., 2013).”