Effect of black holes in local dwarf spheroidal galaxies on gamma-ray constraints on dark matter annihilation

González‐Morales, Alma X.; Profumo, Stefano; Queiroz, Farinaldo S.

doi:10.1103/physrevd.90.103508

Cited by 39 publications

(46 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Yet greater emphasis in the literature has been on constraining DM annihilation cross sections. In [18], the authors focused on how to distinguish a signal coming from DM annihilation and/or decay using dSphs observations from gamma-ray experiments, whereas in [19] a multi-wavelength approach was performed for annihilating DM, and in [21] the impact of hosting intermediate massive black holes was investigated. Various aspects of DM annihilation in these contexts were explored in [20].…”

Section: Introductionmentioning

confidence: 99%

New limits on the dark matter lifetime from dwarf spheroidal galaxies using Fermi-LAT

et al. 2016

Self Cite

View full text Add to dashboard Cite

Dwarf spheroidal galaxies (dSphs) are promising targets for the indirect detection of dark matter through gamma-ray emission due to their proximity, lack of astrophysical backgrounds and high dark matter density. They are often used to place restrictive bounds on the dark matter annihilation cross section. In this paper, we analyze six years of Fermi-LAT gamma-ray data from 19 dSphs that are satellites of the Milky Way, and derive from a stacked analysis of 15 dSphs, robust 95% confidence level lower limits on the dark matter lifetime for several decay channels and dark matter masses between ∼ 1 GeV and 10 TeV. Our findings are based on a bin-by-bin maximum likelihood analysis treating the J-factor as a nuisance parameter using PASS 8 event-class. Our constraints from this ensemble are among the most stringent and solid in the literature, and competitive with existing ones coming from the extragalactic gamma-ray background, galaxy clusters, AMS-02 cosmic ray data, Super-K and ICECUBE neutrino data, while rather insensitive to systematic uncertainties. In particular, among gamma-ray searches, we improve existing limits for dark matter decaying intobb (µ + µ − ) for DM masses below ∼ 30 (200) GeV, demonstrating that dSphs are compelling targets for constraining dark matter decay lifetimes.

show abstract

Section: Introductionmentioning

confidence: 99%

New limits on the dark matter lifetime from dwarf spheroidal galaxies using Fermi-LAT

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…To reconcile the discrepancy we discuss plausible alternatives for our model for the Galactic halo and spike, as well as different allowed choices for the DM particle physics properties. We emphasize the importance of incorporating both SMBH spike and halo components in future analyses of GC annihilation fluxes.The effects of adiabatic black hole-induced DM spikes on the isotropic diffuse gamma-ray background have been considered in [19], while the effects on gamma rays of potential spikes in dwarf galaxies were studied in [20].The Canonical Model: Galactic Center Halo and Spike. We assume that the DM is collisionless and adopt a cuspy, spherical, DM matter density profile obeying a NFW like-halo profile.…”

mentioning

confidence: 99%

Galactic Center Gamma-Ray Excess from Dark Matter Annihilation: Is There a Black Hole Spike?

2014

View full text Add to dashboard Cite

If the supermassive black hole Sgr A * at the center of the Milky Way grew adiabatically from an initial seed embedded in an NFW dark matter (DM) halo, then the DM profile near the hole has steepened into a spike. We calculate the dramatic enhancement to the gamma ray flux from the Galactic center (GC) from such a spike if the 1-3 GeV excess observed in Fermi data is due to DM annihilations. We find that for the parameter values favored in recent fits, the point source-like flux from the spike is 35 times greater than the flux from the inner 1• of the halo, far exceeding all Fermi point source detections near the GC. We consider the dependence of the spike signal on astrophysical and particle parameters and conclude that if the GC excess is due to DM, then a canonical adiabatic spike is disfavored by the data. We discuss alternative Galactic histories that predict different spike signals, including: (i) the nonadiabatic growth of the black hole, possibly associated with halo and/or black hole mergers, (ii) gravitational interaction of DM with baryons in the dense core, such as heating by stars, or (iii) DM self-interactions. We emphasize that the spike signal is sensitive to a different combination of particle parameters than the halo signal, and that the inclusion of a spike component to any DM signal in future analyses would provide novel information about both the history of the GC and the particle physics of DM annihilations.The indirect detection of high-energy particles originating in dark matter (DM) annihilations or decays is a cornerstone in the search for DM (see, e.g., [1] for a recent review). Annihilations in the Galactic halo may lead to a signal from the Galactic center (GC) at rates that are observable by the current generation of high-energy experiments. The excess of ∼ 1 − 3 GeV gamma rays from the inner few degrees of the GC observed in Fermi telescope data may be such a signal [2][3][4][5][6][7][8][9][10][11]. A recent analysis [11] of the Fermi data with improved angular resolution [12] has sharpened the case for a DM interpretation of the excess, demonstrating a clear preference for a component of emission from a spherically symmetric, extended source with an energy spectrum apparently independent of position.A supermassive black hole (SMBH) exists at the site of Sgr A * [13,14]. Such an object should steepen the DM density profile in its sphere of influence. If the SMBH grows adiabatically from a smaller seed, the resulting density spike yields a strong enhancement of any DM annihilation signal [15][16][17]. Here we construct a canonical GC model containing an adiabatic density spike. We adopt the best-fit halo and particle parameters found in [11] to calculate the expected gamma-ray flux and spectrum from both the spike and ambient Navarro-FrenkWhite (NFW [18]) halo regions. We find that the expected flux from the spike in our canonical model considerably exceeds the flux from any of the pointlike sources near the GC cataloged by Fermi. To reconcile the discrepancy we discuss plausible al...

show abstract

“…This possibility has been investigated in the literature, both in the classic and relativistic approach [13,14]. The resultant boost factor could be of several orders of magnitude, depending on the assumptions about the initial density profile and BH growing history [14,15]. Further studies have taken into account the dynamical effect of the stars [16] or the instantaneous, or slow growth, of the BH [14] contributions that effectively reduce such an enhancement.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the very inner Milky Way dark matter distribution and gamma-ray signals

et al. 2016

View full text Add to dashboard Cite

We analyze the possibility that the HESS γ-ray source at the Galactic center could be explained as the secondary flux produced by annihilation of TeV dark matter (DM) particles with locally enhanced density, in a region spatially compatible with the HESS observations themselves. We study the inner 100 pc considering (i) the extrapolation of several density profiles from state-of-the-art N-body þ hydrodynamics simulations of Milky Way-like galaxies, (ii) the DM spike induced by the black hole, and (iii) the DM particles scattering off by bulge stars. We show that in some cases the DM spike may provide the enhancement in the flux required to explain the cutoff in the HESS J1745-290γ-ray spectra as TeV DM. In other cases, it may help to describe the spatial tail reported by HESS II at angular scales ≲0.54°toward Sgr A Ã .

show abstract

Effect of black holes in local dwarf spheroidal galaxies on gamma-ray constraints on dark matter annihilation

Cited by 39 publications

References 58 publications

New limits on the dark matter lifetime from dwarf spheroidal galaxies using Fermi-LAT

New limits on the dark matter lifetime from dwarf spheroidal galaxies using Fermi-LAT

Galactic Center Gamma-Ray Excess from Dark Matter Annihilation: Is There a Black Hole Spike?

Analysis of the very inner Milky Way dark matter distribution and gamma-ray signals

Contact Info

Product

Resources

About