Dark matter and pulsar model constraints from Galactic Center Fermi-LAT gamma-ray observations

By C. Gordon, O. Macias. 2013

362 citations recorded by the source corpus.

Employing Fermi-LAT gamma ray observations, several independent groups have found excess extended gamma ray emission at the Galactic center (GC). Both, annihilating dark matter (DM) or a population of $\sim 10^3$ unresolved millisecond pulsars (MSPs) are regarded as well motivated possible explanations. However, there is significant uncertainties in the diffuse galactic background at the GC. We have performed a revaluation of these two models for the extended gamma ray source at the GC by accounting for the systematic uncertainties of the Galactic diffuse emission model. We also marginalize over point source and diffuse background parameters in the region of interest. We show that the excess emission is significantly more extended than a point source. We find that the DM (or pulsars population) signal is larger than the systematic errors and therefore proceed to determine the sectors of parameter space that provide an acceptable fit to the data. We found that a population of order a 1000 MSPs with parameters consistent with the average spectral shape of Fermi-LAT measured MSPs was able to fit the GC excess emission. For DM, we found that a pure $\tau^+\tau^-$ annihilation channel is not a good fit to the data. But a mixture of $\tau^+\tau^-$ and $b\bar{b}$ with a $\left $ of order the thermal relic value and a DM mass of around 20 to 60 GeV provides an adequate fit.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/3d956325810a0914c174bb0db206a186a087da44

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Citations in the corpus

Background model systematics for the Fermi GeV excess (2014, background): “Our results concerning the DM interpretation of the Galactic center excess are in reasonable agreement (at 95% CL) with most of the previous results from the inner Galaxy [55, 62] and Galactic center [65] analyses, however they are in slight tension (at 99% CL) with some result from the inner few de”
Dark nuclei. I. Cosmology and indirect detection (2014, background): “Having discussed the broad indirect detection features of dark nucleosynthesis, we will now show the utility of this process by entertaining the possibility that the gamma ray excess at the galactic center is due to DM [81–89], specifically considering an interpretation in terms of dark nucleosynthe”
An Introduction to Particle Dark Matter (2019, neutral): “[2, 27, 42].”
A tale of tails: Dark matter interpretations of the Fermi GeV excess in light of background model systematics (2014, methodology): “In most of the previous studies on the GeV excess [11,12,14,15,24] the contribution from the Galactic diffuse emission has been modeled by using the P6V11 model provided by the Fermi-LAT Collaboration.”
SEARCHING FOR DARK MATTER ANNIHILATION IN RECENTLY DISCOVERED MILKY WAY SATELLITES WITH FERMI-LAT (2016, background): “In all cases, pglobal 1σ. Due to the lack of a significant excess in the combined analysis, we conclude that there is no significant evidence of DM annihilation in the population of confirmed and candidate dSphs. 7 If we only tested the single DM model best-fit to the GCE then it would not be nece”
The impact of baryonic physics on the structure of dark matter haloes: the view from the FIRE cosmological simulations (2015, background): “…(Goodenough & Hooper 2009; Hooper & Goodenough 2011; Hooper & Linden 2011; Boyarsky et al. 2011; Abazajian & Kapling- c© 0000 RAS, MNRAS 000, 000–000 hat 2012; Gordon & Macías 2013; Macias & Gordon 2014; Abazajian et al. 2014) although other possibilities remain valid alternatives (Abazajian 2011).”
Galactic Center gamma-ray ``excess'' from an active past of the Galactic Centre? (2014, background): “Very recently, in [11, 14] some effort was put in quantifying some of these systematics, and it was concluded that in particular below 1 GeV the shape of the spectrum is highly model dependent.”
The Fermi Galactic Center GeV Excess and Implications for Dark Matter (2017, methodology): “…emission and point sources (PSs; e.g., Goodenough & Hooper 2009; Vitale et al. 2009; Hooper & Goodenough 2011; Abazajian & Kaplinghat 2012; Gordon & Macías 2013; Hooper & Slatyer 2013; Calore et al. 2015; Zhou et al. 2015; Ajello et al. 2016; Daylan et al. 2016), while other groups…”
SEARCH FOR GAMMA-RAY EMISSION FROM DES DWARF SPHEROIDAL GALAXY CANDIDATES WITH FERMI-LAT DATA (2015, background): “The population of nearby DM-dominated dSphs represents an independent set of targets to test possible signals of DM annihilation in other regions such as the Galactic center (e.g., Gordon & Macias 2013; Abazajian et al 2014; Calore et al. 2015; Daylan et al. 2014).”
Toward (finally!) ruling out Z and Higgs mediated dark matter models (2016, background): “In the currently allowed mass range near the Higgs pole, this class of models predicts a very small low-velocity annihilation cross section, which is likely unable to generate the measured intensity of the Galactic Center gamma-ray excess [42–48] (see also, Refs.”