All about baryons: revisiting SIDM predictions at small halo masses

Fry, Alexander B.; Governato, Fabio; Pontzen, Andrew; Quinn, Thomas; Tremmel, Michael; Anderson, Lauren; Menon, Harshitha; Brooks, Alyson; Wadsley, James

doi:10.1093/mnras/stv1330

Cited by 107 publications

(127 citation statements)

References 97 publications

(152 reference statements)

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…Future studies will be able to quantify such scatter, and its mass dependence, which may result in a better match between the SIDM model and observations for smaller core sizes. It is certainly also possible (as recently shown in Fry et al 2015) that baryonic physics would affect the dark matter density profiles in a SIDM universe, in a mass dependent manner.…”

Section: Discussionmentioning

confidence: 85%

The variation of rotation curve shapes as a signature of the effects of baryons on dark matter density profiles

Brook

2015

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

Rotation curves of galaxies show a wide range of shapes, which can be paramaterized as scatter in V rot (1kpc)/V max i.e. the ratio of the rotation velocity measured at 1 kpc and the maximum measured rotation velocity. We examine whether the observed scatter can be accounted for by combining scatters in disc scale-lengths, the concentration-halo mass relation, and the M -M halo relation. We use these scatters to create model galaxy populations; when housed within dark matter halos that have universal, NFW density profiles, the model does not match the lowest observed values of V rot (1kpc)/V max and has too little scatter in V rot (1kpc)/V max compared to observations. By contrast, a model using a mass dependent dark matter profile, where the inner slope is determined by the ratio of M /M halo , produces galaxies with low values of V rot (1kpc)/V max and a much larger scatter, both in agreement with observation. We conclude that the large observed scatter in V rot (1kpc)/V max favours density profiles that are significantly affected by baryonic processes. Alternative dark matter core formation models such as SIDM may also account for the observed variation in rotation curve shapes, but these observations may provide important constraints in terms of core sizes, and whether they vary with halo mass and/or merger history.

show abstract

Section: Discussionmentioning

confidence: 85%

The variation of rotation curve shapes as a signature of the effects of baryons on dark matter density profiles

Brook

2015

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

show abstract

“…Generally, m s below 0.1 cm g 2 1 -have been found to be indistinguishable from CDM models . In low-mass galaxies with maximum circular velocity of V max  m 30 km s , 1 s -, values ranging from 0.5 to 10 cm g 2 1 -alleviate the core-cusp and TBTF (Vogelsberger et al 2012;Zavala et al 2013;Elbert et al 2015;Fry et al 2015).…”

Section: Properties Of Viable Sidm Modelsmentioning

confidence: 99%

“…This is complementary to the approach of running full-fledged hydrodynamic simulations that include self-interactions between DM particles. Vogelsberger et al (2014) and Fry et al (2015) examine dwarf galaxies (M M 10 v 10  ) using fully self-consistent hydrodynamic simulations and find that observable cores are still formed in these dwarfs in SIDM. Fry et al (2015) find that the cores in their simulated dwarfs are not substantially different from those formed purely via feedback in their CDM simulations.…”

Section: Motivation: Contraction Of Sidm Halosmentioning

confidence: 99%

“…Vogelsberger et al (2014) and Fry et al (2015) examine dwarf galaxies (M M 10 v 10  ) using fully self-consistent hydrodynamic simulations and find that observable cores are still formed in these dwarfs in SIDM. Fry et al (2015) find that the cores in their simulated dwarfs are not substantially different from those formed purely via feedback in their CDM simulations. It is not clear how these results generalize to larger halo masses, where feedback is expected to be less important in driving core formation in CDM halos and halo contraction effects are expected to dominate (e.g., Di Cintio et al 2014; Dutton et al 2016;Fiacconi et al 2016).…”

Section: Motivation: Contraction Of Sidm Halosmentioning

confidence: 99%

See 1 more Smart Citation

A Testable Conspiracy: Simulating Baryonic Effects on Self-interacting Dark Matter Halos

Elbert

Bullock

Kaplinghat

et al. 2018

ApJ

105

115

View full text Add to dashboard Cite

We investigate the response of self-interacting dark matter (SIDM) halos to the growth of galaxy potentials using idealized simulations, with each run in tandem with collisionless cold dark matter (CDM). We find that if the stellar potential strongly dominates in the central parts of a galaxy, then SIDM halos can be as dense as CDM halos on observable scales. For extreme cases, core collapse can occur, leading to SIDM halos that are denser and cuspier than their CDM counterparts. If the stellar potential is not dominant, then SIDM halos retain isothermal cores with densities far below CDM predictions. When a disk is present, the inner SIDM halo becomes more flattened in the disk plane than the CDM halo.  s -is disfavored for DM collision velocities above about 1500 km s −1 . More generally, the interaction between baryonic potentials and SIDM densities offers new directions for constraining SIDM cross-sections in galaxies where baryons are dynamically important.

show abstract

“…Fry et al (2015) have used cosmological hydrodynamical simulations to show that SIDM does not modify the central density of the dark halo in dwarfs with peak velocities of less than 30km s −1 , a range where baryonic feedback effects are also inefficient, while, above that, baryonic feedback dominates and leads to results almost identical to CDM, at least for a fixed 2 cm 2 g −1 SIDM cross-section. It remains to be seen how SIDM models with a velocitydependent cross-section would behave.…”

Section: Introductionmentioning

confidence: 99%

Constraining the Nature of Dark Matter with the Star-formation History of the Faintest Local Group Dwarf Galaxy Satellites

Chau

Mayer

Governato

2017

ApJ

View full text Add to dashboard Cite

Λ warm dark matter (ΛWDM), realized by collisionless particles of 1-3 keV, has been proposed as an alternative scenario to Λ-Cold-Dark Matter (ΛCDM) for the dwarf galaxy scale discrepancies. We present an approach to test the viability of such WDM models using star-formation histories (SFHs) of the dwarf spheroidal galaxies (dSphs) in the Local Group. We compare their high-time-resolution SFHs with the collapse redshift of their dark halos in CDM and WDM. Collapse redshift is inferred after determining the subhalo infall mass. This is based on the dwarf current mass inferred from stellar kinematics, combined with cosmological simulation results on subhalo evolution. WDM subhalos close to the filtering mass scale, forming significantly later than CDM, are the most difficult to reconcile with early truncation of star formation (z 3). The ultra-faint dwarfs (UFDs) provide the most stringent constraints. Using six UFDs and eight classical dSphs, we show that a 1 keV particle is strongly disfavored, consistently with other reported methods. Excluding other models is only hinted for a few UFDs. Other UFDs for which the lack of robust constraints on halo mass prevents us from carrying out our analysis rigorously, show a very early onset of star formation that will strengthen the constraints delivered by our method in the future. We discuss the various caveats, notably the low number of dwarfs with accurately determined SFHs and the uncertainties when determining the subhalo infall mass, most notably the baryonic physics. Our preliminary analysis may serve as a pathfinder for future investigations that will combine accurate SFHs for local dwarfs with direct analysis of WDM simulations with baryons. Abstract Λ warm dark matter (ΛWDM), realized by collisionless particles of 1-3 keV, has been proposed as an alternative scenario to Λ-Cold-Dark Matter (ΛCDM) for the dwarf galaxy scale discrepancies. We present an approach to test the viability of such WDM models using star-formation histories (SFHs) of the dwarf spheroidal galaxies (dSphs) in the Local Group. We compare their high-time-resolution SFHs with the collapse redshift of their dark halos in CDM and WDM. Collapse redshift is inferred after determining the subhalo infall mass. This is based on the dwarf current mass inferred from stellar kinematics, combined with cosmological simulation results on subhalo evolution. WDM subhalos close to the filtering mass scale, forming significantly later than CDM, are the most difficult to reconcile with early truncation of star formation (z3). The ultra-faint dwarfs (UFDs) provide the most stringent constraints. Using six UFDs and eight classical dSphs, we show that a 1 keV particle is strongly disfavored, consistently with other reported methods. Excluding other models is only hinted for a few UFDs. Other UFDs for which the lack of robust constraints on halo mass prevents us from carrying out our analysis rigorously, show a very early onset of star formation that will strengthen the constraints delivered by our metho...

show abstract

All about baryons: revisiting SIDM predictions at small halo masses

Cited by 107 publications

References 97 publications

The variation of rotation curve shapes as a signature of the effects of baryons on dark matter density profiles

The variation of rotation curve shapes as a signature of the effects of baryons on dark matter density profiles

A Testable Conspiracy: Simulating Baryonic Effects on Self-interacting Dark Matter Halos

Constraining the Nature of Dark Matter with the Star-formation History of the Faintest Local Group Dwarf Galaxy Satellites

Contact Info

Product

Resources

About