We detect a line at 3.539±0.011 keV in the deep exposure data set of the Galactic center region, observed with the x-ray multi-mirror mission Newton. The dark matter interpretation of the signal observed in the Perseus galaxy cluster, the Andromeda galaxy [A. Boyarsky et al., Phys. Rev. Lett. 113, 251301 (2014)], and in the stacked spectra of galaxy clusters [E. Bulbul et al., Astrophys. J. 789, 13 (2014)], together with nonobservation of the line in blank-sky data, put both lower and upper limits on the possible intensity of the line in the Galactic center data. Our result is consistent with these constraints for a class of Milky Way mass models, presented previously by observers, and would correspond to the radiative decay dark matter lifetime, τDM∼6-8×10(27) sec. Although it is hard to exclude an astrophysical origin of this line based on the Galactic center data alone, this is an important consistency check of the hypothesis that encourages us to check it with more observational data that are expected by the end of 2015.
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http://dx.doi.org/10.1103/PhysRevLett.115.161301 | DOI Listing |
Nanoscale
January 2025
State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an, 710049, China.
Two-dimensional (2D) organic-inorganic halide perovskites are promising sensitive materials for optoelectronic applications due to their strong light-matter interactions, layered structure, long carrier lifetime and diffusion length. However, a high gate bias is indispensable for perovskite-based phototransistors to optimize detection performances, since ion migration seriously screens the gate electric field and the deposition process introduces intrinsic defects, which induces severe leakages and large power dissipation. In this work, an ultrasensitive phototransistor based on the (PEA)SnI perovskite and the Al:HfO ferroelectric layer is meticulously studied, working without an external gate voltage.
View Article and Find Full Text PDFJ Low Temp Phys
December 2024
Physik-Department, Technische Universität München, Garching, Germany.
Any experiment aiming to measure rare events, like Coherent Elastic neutrino-Nucleus Scattering (CE NS) or hypothetical Dark Matter scattering, via nuclear recoils in cryogenic detectors relies crucially on a precise detector calibration at sub-keV energies. The Crab collaboration developed a new calibration technique based on the capture of thermal neutrons inside the target crystal. Together with the Nucleus experiment, first measurements with a moderated Cf neutron source and a cryogenic detector were taken.
View Article and Find Full Text PDFEnviron Sci Technol Lett
January 2025
PSI Center for Energy and Environmental Sciences, Paul Scherrer Institute, 5232 Villigen, Switzerland.
Oxidative potential (OP) is increasingly recognized as a more health-relevant metric than particulate matter (PM) mass concentration because of its response to varying chemical compositions. Given the limited research on the OP of complex combustion aerosols, the effects of aging processes on their OP remain underexplored. We used online instruments to track the evolution of OP [via dithiothreitol (DTT) assays] during the aging of wood burning and coal combustion emissions by hydroxyl-radical-driven photooxidation and dark ozonolysis.
View Article and Find Full Text PDFEur Phys J C Part Fields
January 2025
Institute for Particle Physics Phenomenology, Department of Physics, Durham University, Durham, DH1 3LE UK.
Extended dark matter objects (EDOs) are popular dark matter candidates that interact gravitationally with the Standard Model. These gravitational interactions can be used to constrain their allowed parameter space. However, EDOs can have different formation mechanisms, sizes, and shapes, requiring a case-by-case analysis when studying their impact on different areas of cosmology.
View Article and Find Full Text PDFPorcine Health Manag
January 2025
Departament de Sanitat i Anatomia Animals, Facultat de Veterinària, Campus de la Universitat Autònoma de Barcelona (UAB), 08193, Bellaterra, Barcelona, Spain.
Background: Digestive disorders are one of the main health problems in suckling piglets. The correct visual identification of feces in suckling piglets is an important tool for the diagnosis of enteric diseases. The aim of the present observational study was to analyze different physicochemical parameters of the feces of suckling piglets aged 0 to 21 days: visual appearance (color and consistency), fecal dry matter (FDM) content and pH.
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