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On the gamma-ray em...
On the gamma-ray emission from the core of the Sagittarius dwarf galaxy
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Evans, Addy J. (author)
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Strigari, Louis E. (author)
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- Svenborn, Oskar (author)
- Stockholms universitet,Fysikum,Oskar Klein-centrum för kosmopartikelfysik (OKC)
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Albert, Andrea (author)
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Harding, J. Patrick (author)
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Hooper, Dan (author)
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- Linden, Tim, 1985- (author)
- Stockholms universitet,Fysikum,Oskar Klein-centrum för kosmopartikelfysik (OKC)
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Pace, Andrew B. (author)
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(creator_code:org_t)
- 2023
- 2023
- English.
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In: Monthly notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 524:3, s. 4574-4585
- Related links:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Subject headings
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- We use Fermi-LAT data to analyse the faint gamma-ray source located at the centre of the Sagittarius (Sgr) dwarf spheroidal galaxy. In the 4FGL-DR3 catalogue, this source is associated with the globular cluster, M54. We investigate the spectral energy distribution and spatial extension of this source, with the goal of testing two hypotheses: (1) the emission is due to millisecond pulsars within M54, or (2) the emission is due to annihilating dark matter from the Sgr halo. For the pulsar interpretation, we consider a two-component model which describes both the lower-energy magnetospheric emission and possible high-energy emission arising from inverse Compton scattering. We find that this source has a point-like morphology at low energies, consistent with magnetospheric emission, and find no evidence for a higher-energy component. For the dark matter interpretation, we find the signal favours a dark matter mass of m(chi)= 29.6 +/- 5.8 GeV and an annihilation cross section of sv = (2. 1 +/- 0.59) x10(-26) cm(3) s(-1) for the b b channel (or m(chi)= 8.3 +/- 3.8 GeV and sv = (0.90 +/- 0.25) x10-26 cm(3) s(-1) for the tau(+) tau(-) channel), when adopting a J -factor of J = 1019.6 GeV2 cm(-5). This parameter space is consistent with gamma-ray constraints from other dwarf galaxies and with dark matter interpretations of the Galactic Centre Gamma-Ray Excess.
Subject headings
- NATURVETENSKAP -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)
Keyword
- astroparticle physics - globular clusters - galaxies
- dwarf - dark matter - gamma-rays
- general
- astroparticle physics
- globular clusters
- galaxies: dwarf
- dark matter
- gamma-rays: general.
Publication and Content Type
- ref (subject category)
- art (subject category)
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