Dark matter in dwarf spheroidal galaxies and indirect detection: a review

Strigari, Louis E.

doi:10.1088/1361-6633/aaae16

Cited by 86 publications

(65 citation statements)

References 142 publications

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“…Because of their diminutive masses, and subsequent sensitivity to dark matter distributions and baryonic processes, it is challenging for galaxy formation theories to generate both the currently observed number and internal structure of dSphs (Bullock & Boylan-Kolchin 2017). They also provide excellent targets for indirect dark matter detection experiments in the Local Group, as their old, quiescent stellar populations and lack of gas minimize astrophysical backgrounds (Strigari 2018). For these reasons, dSphs provide an important small-scale constraint to theories of dark matter and cosmology.…”

Section: Introductionmentioning

confidence: 99%

Stellar Density Profiles of Dwarf Spheroidal Galaxies

Moskowitz

Walker

2020

ApJ

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We apply a flexible parametric model, a combination of generalized Plummer profiles, to infer the shapes of the stellar density profiles of the Milky Way's satellite dwarf spheroidal galaxies (dSphs). We apply this model to 38 dSphs using star counts from the Sloan Digital Sky Survey, PanStarrs-1 Survey, and Dark Energy Survey. Using mock data, we examine systematic errors associated with modelling assumptions and identify conditions under which our model can identify 'non-standard' stellar density profiles that have central cusps and/or steepened outer slopes. Applying our model to real dwarf spheroidals, we do not find evidence for centrally cusped density profiles among the ∼ 10 Milky Way satellites for which our tests with mock data indicate there would be sufficient detectability. We do detect steepened (with respect to a standard Plummer model) outer profiles in several dSphs-Fornax, Leo I, Leo II, Reticulum II-which may point to distinct evolutionary pathways for these objects. However, the outer slope of the stellar density profile does not yet obviously correlate with other observed galaxy properties.

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Section: Introductionmentioning

confidence: 99%

Stellar Density Profiles of Dwarf Spheroidal Galaxies

Moskowitz

Walker

2020

ApJ

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“…Galactic diffuse emission). "Cleaner" and, in this respect, more promising targets for DM identification are dwarf spheroidal galaxies, optically faint galaxies whose dynamics has been proved to be dominated by large haloes of DM [6]. Those faintest detectable galaxies can probe the WIMP paradigm with multi wavelength observations: from optical to gamma rays (see for example [7,8]).…”

Section: Introductionmentioning

confidence: 99%

Gamma-Ray Sensitivity to Dark Matter Subhalo Modelling at High Latitudes

2019

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Searches for "dark" subhaloes in gamma-ray point-like source catalogues are among promising strategies for indirect dark matter detection. Such a search is nevertheless affected by uncertainties related, on the one hand, to the modelling of the dark matter subhalo distribution in Milky-Way-like galaxies, and, on the other hand, to the sensitivity of gamma-ray instruments to the dark matter subhalo signals. In the present work, we assess the detectability of dark matter subhaloes in Fermi-LAT catalogues, taking into accounts uncertainties associated with the modelling of the Galactic subhalo population. We use four different halo models bracketing a large set of uncertainties. For each model, adopting an accurate detection threshold of the LAT to dark matter subhalo signals and comparing model predictions with the number of unassociated point-sources in Fermi-LAT catalogues, we derive upper limits on the annihilation cross section as a function of dark matter mass. Our results show that, even in the best-case scenario (i.e. DMonly subhalo model), which does not include tidal disruption from baryons, the limits on the dark matter parameter space are less stringent than current gamma-ray limits from dwarf spheroidal galaxies. Comparing the results obtained with the different subhalo models, we find that baryonic effects on the subhalo population are significant and lead to dark matter constraints that are less stringent by a factor of ∼2 to ∼5. This uncertainty comes from the unknown resilience of dark matter subhaloes to tidal disruption.

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“…Dwarf spheroidal galaxies (dSphs) provide an excellent aim for indirect DM searches. They typically have high dark-to-luminous mass ratios, own very little gamma-ray sources and most of them are located well above the Galactic plane, where the diffuse astrophysical foreground is low [77]. If dSphs are dominated by the same kind of DM that creates the DAMPE excess, they can be used to impose constraints on the annihilation cross section.…”

Section: Discussionmentioning

confidence: 99%

The DAMPE excess and gamma-ray constraints

Belotsky

Kamaletdinov

Laletin

et al. 2019

Physics of the Dark Universe

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The direct measurements of the cosmic electron-positron spectrum around 1 TeV made by DAMPE have induced many theoretical speculations about possible excesses in the data above the standard astrophysical predictions that might have the dark matter (DM) origin. These attempts mainly fall into two categories: i) DM annihilations (or decays) in the Galactic halo producing the broad spectrum excess; ii) DM annihilations in the nearby compact subhalo producing the sharp peak at 1.4 TeV. We investigate the gamma-ray emission accompanying e + e − production in DM annihilations, as well as various theoretical means to suppress the prompt radiation, such as specific interaction vertices or multi-cascade modes, and conclude that these attempts are in tension with various gamma-ray observations. We show that the DM explanations of the broad spectrum excess tend to contradict the diffuse isotropic gamma-ray background (IGRB), measured by Fermi-LAT, while the nearby subhalo scenario is constrained by nonobservation in the surveys, performed by Fermi-LAT, MAGIC and HESS. We also briefly review other types of gamma-ray constraints, which seem to rule out the DM interpretations of the DAMPE broad spectrum excess as well.

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Dark matter in dwarf spheroidal galaxies and indirect detection: a review

Cited by 86 publications

References 142 publications

Stellar Density Profiles of Dwarf Spheroidal Galaxies

Stellar Density Profiles of Dwarf Spheroidal Galaxies

Gamma-Ray Sensitivity to Dark Matter Subhalo Modelling at High Latitudes

The DAMPE excess and gamma-ray constraints

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