| 1. |
- Ackermann, M., et al.
(författare)
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The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
- 2015
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 799:1, s. 86-
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Tidskriftsartikel (refereegranskat)abstract
- The gamma-ray sky can be decomposed into individually detected sources, diffuse emission attributed to the interactions of Galactic cosmic rays with gas and radiation fields, and a residual all-sky emission component commonly called the isotropic diffuse gamma-ray background (IGRB). The IGRB comprises all extragalactic emissions too faint or too diffuse to be resolved in a given survey, as well as any residual Galactic foregrounds that are approximately isotropic. The first IGRB measurement with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) used 10 months of sky-survey data and considered an energy range between 200 MeV and 100 GeV. Improvements in event selection and characterization of cosmic-ray backgrounds, better understanding of the diffuse Galactic emission (DGE), and a longer data accumulation of 50 months allow for a refinement and extension of the IGRB measurement with the LAT, now covering the energy range from 100 MeV to 820 GeV. The IGRB spectrum shows a significant high-energy cutoff feature and can be well described over nearly four decades in energy by a power law with exponential cutoff having a spectral index of 2.32 +/- 0.02 and a break energy of (279 +/- 52) GeV using our baseline DGE model. The total intensity attributed to the IGRB is (7.2 +/- 0.6) x 10(-6) cm(-2) s(-1) sr(-1) above 100 MeV, with an additional +15%/-30% systematic uncertainty due to the Galactic diffuse foregrounds.
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| 2. |
- Armengaud, E., et al.
(författare)
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Physics potential of the International Axion Observatory (IAXO)
- 2019
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :6
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Tidskriftsartikel (refereegranskat)abstract
- We review the physics potential of a next generation search for solar axions: the International Axion Observatory (IAXO). Endowed with a sensitivity to discover axion-like particles (ALPs) with a coupling to photons as small as g(a gamma) similar to 10(-12) GeV-1, or to electrons g(ae) similar to 10(-13), IAXO has the potential to find the QCD axion in the 1 meV similar to 1 eV mass range where it solves the strong CP problem, can account for the cold dark matter of the Universe and be responsible for the anomalous cooling observed in a number of stellar systems. At the same time, IAXO will have enough sensitivity to detect lower mass axions invoked to explain: 1) the origin of the anomalous transparency of the Universe to gamma-rays, 2) the observed soft X-ray excess from galaxy clusters or 3) some inflationary models. In addition, we review string theory axions with parameters accessible by IAXO and discuss their potential role in cosmology as Dark Matter and Dark Radiation as well as their connections to the above mentioned conundrums.
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| 4. |
- Deodati, A, et al.
(författare)
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Serum Levels of Polybrominated Diphenyl Ethers in Girls with Premature Thelarche
- 2016
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Ingår i: Hormone research in paediatrics. - : S. Karger AG. - 1663-2826 .- 1663-2818. ; 86:4, s. 233-239
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Tidskriftsartikel (refereegranskat)abstract
- <b><i>Background/Aims:</i></b> Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants and have shown endocrine disruption properties in experimental studies. The aim of this study was to investigate the association between the exposure to PBDEs and alterations of puberty in girls referred for idiopathic central precocious puberty (ICPP) and premature thelarche (PT). <b><i>Methods:</i></b> A case-control study was conducted in 124 girls: 37 girls with ICPP (mean age 7.4 ± 0.9 years), 56 with PT (mean age 5.7 ± 2.1 years) and 31 controls (mean age 5.4 ± 1.9 years). PBDE serum concentrations, hormone levels and anthropometry were assessed. PBDE concentrations were corrected for total serum lipid content. Individual exposure to PBDEs was evaluated through ad hoc questionnaires. <b><i>Results:</i></b> PBDE serum concentrations corrected for total lipid content were significantly higher in girls with PT (mean 1.49 ± 0.63 log ng/g) than in controls (mean 1.23 ± 0.54 log ng/g; p < 0.05). PT girls showed higher levels of PBDE than ICPP girls (1.49 ± 0.63 vs. 1.37 ± 0.49 log ng/g), though this was not significant. An analysis of the questionnaires revealed no significant differences in exposure between the three groups. <b><i>Conclusion: </i></b>Our findings suggest that higher concentrations of serum PBDEs are associated with PT in girls.
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