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Opis: The Cherenkov Telescope Array (CTA) will have a unique chance of discovery for a large range of masses in Weakly Interacting Massive Particles models of dark matter. The principal target for dark matter searches with CTA is the centre of the Galactic Halo. The best strategy is to perform CTA observations within a few degrees of the Galactic Centre, with the Galactic Centre itself and the most intense diffuse emission regions removed from the analysis. Assuming a cuspy dark matter density profile for the Milky Way, 500 hours of observations in this region provide sensitivities to and below the thermal cross-section of dark matter annihilations, for masses between a few hundred GeV and a few tens of TeV; therefore CTA will have a significant chance of discovery in some models. Since the dark matter density in the Milky Way is far from certain in the inner kpc region, other targets are also proposed for observation, like ultra-faint dwarf galaxies such as Segue 1 with 100 hours per year proposed. Beyond these two observational targets, further alternatives, such as Galactic dark clumps, will be considered closer to the actual date of CTA operations. Sensitivity predictions for dark matter searches are given on the various targets taking into account the latest instrument response functions expected for CTA together with a discussion on the systematic uncertainties from the backgrounds.
Najdeno v: osebi
Ključne besede: dark matter, gamma-ray astronomy
Objavljeno: 01.03.2016; Ogledov: 1751; Prenosov: 138
Polno besedilo (724,07 KB)

Opis: The Fermi Large Area Telescope (LAT) has provided the most detailed view to date of the emission toward the Galactic center (GC) in high-energy γ-rays. This paper describes the analysis of data taken during the first 62 months of the mission in the energy range 1–100 GeV from a 15° × 15° region about the direction of the GC. Specialized interstellar emission models (IEMs) are constructed to enable the separation of the γ-ray emissions produced by cosmic ray particles interacting with the interstellar gas and radiation fields in the Milky Way into that from the inner ∼1 kpc surrounding the GC, and that from the rest of the Galaxy. A catalog of point sources for the 15° × 15° region is self-consistently constructed using these IEMs: the First Fermi-LAT Inner Galaxy Point Source Catalog (1FIG). The spatial locations, fluxes, and spectral properties of the 1FIG sources are presented, and compared with γ-ray point sources over the same region taken from existing catalogs. After subtracting the interstellar emission and point-source contributions a residual is found. If templates that peak toward the GC are used to model the positive residual the agreement with the data improves, but none of the additional templates tried account for all of its spatial structure. The spectrum of the positive residual modeled with these templates has a strong dependence on the choice of IEM.
Najdeno v: osebi
Ključne besede: cosmic rays – Galaxy: center – gamma-rays: general – gamma-rays: ISM – radiation mechanisms: non-thermal
Objavljeno: 02.03.2016; Ogledov: 1948; Prenosov: 149
Polno besedilo (6,36 MB)

Najdeno v: osebi
Ključne besede: Cherenkov Telescope Array (CTA), very-high energy (VHE) gamma-ray emission, star-forming regions, the Cygnus region, observational strategy optimization
Objavljeno: 11.03.2016; Ogledov: 1836; Prenosov: 162
Polno besedilo (585,14 KB)

Najdeno v: osebi
Ključne besede: Cherenkov Telescope Array, Gamma-Ray Bursts, very-high energy (VHE) gamma-ray emission, observational strategy optimization
Objavljeno: 11.03.2016; Ogledov: 1829; Prenosov: 125
Polno besedilo (133,05 KB)

Najdeno v: osebi
Ključne besede: Cherenkov Telescope Array (CTA), sensitivity, background rejection, silicon photomultipliers, cosmic rays, positron excess, Earth-Moon spectrometer
Objavljeno: 14.03.2016; Ogledov: 1573; Prenosov: 138
Polno besedilo (229,59 KB)